MVHR Filters

Q: What filter classes are used in Systemair SAVE VTR units?

Most SAVE units use two classes:M5 extract filterF7 (ePM1) supply filterSome models differ: the SAVE VTR 200 (BF), VTR 300 (BF) and VR 250 take a coarser G3 extract filter with F7 supply, the VSR 150 comes with G3 or M5 extract, and the VTC 200 takes G4+G4. Each product page shows the exact classes for your model.

MVHR filters

Customer Reviews

Kõik filtrid selgelt arusaadavad, lihtne tellida.

Aare Kevvai

Facebook review

Ostsin endale Komfovent seadmele uued filtrid. Tarne oli üllatavalt kiire ning tooted täpselt need, mis lubatud. Sain kiirelt ja lihtsalt need ära vahetada ning kõik toimib ideaalselt!

Ronald Y

Google review

Tippklassi teenus ja tooted! Filtrite ostmine oli lihtne ja mugav, ning kaup jõudis kiirelt kohale. Kvaliteet on silmnähtav. Kindel soovitus!

Kaspar K

Google review

Erittäin hyvä palvelu! Mieluisa ostokokemus.

Kenneth Tarvonen

Google review

Korralik kaup, kiire tarne.

Olle-Marek Kaljuvee

Google review

Originaal filtrid turu parima hinnaga, olen väga rahul.

Haljand Martinson

Google review

kaup käes, kõik sujus

Teet Lumeste

Google review

Esialgu saadeti vales mõõdus filtrid, aga seejärel parandati eksimus ülimalt kiiresti. Uus kaup oli juba teel enne algse tellimuse tagastamist!

Silver Tilk

Google review

Need Help? Start Here.

We’ve gathered answers to the most common questions about our products and services. If you can’t find an answer here, please contact us directly.

Which Systemair SAVE models (VTR 150, 275, 300, 500, 700, VSR 200) does your filter range cover?

We supply filters for Systemair's SAVE range – VTR, VSR, VTC and VR models, including the VTR 150, 275, 300, 500 and 700 and the VSR 200 – one of the most widely installed residential and light-commercial MVHR series in Europe. The exact model and variant code (e.g. VTR 300 (PF)) is printed on the label on the unit's front panel – the most reliable way to choose the right filter.

What filter classes are used in Systemair SAVE VTR units?

Most SAVE units use two classes:

M5 extract filter
F7 (ePM1) supply filter

Some models differ: the SAVE VTR 200 (BF), VTR 300 (BF) and VR 250 take a coarser G3 extract filter with F7 supply, the VSR 150 comes with G3 or M5 extract, and the VTC 200 takes G4+G4. Each product page shows the exact classes for your model.

Can I order a multi-year supply of Systemair SAVE filters at once?

Yes, ordering multiple sets several years ahead is a popular choice among SAVE VTR and VSR owners who'd rather order filters once a year than remember to do it separately every 3–6 months. Such bulk orders are usually cheaper per unit than buying one at a time. Before ordering a larger quantity, be sure to confirm your exact VTR model code (e.g. VTR 500 or VTR 700), as filter dimensions vary between different SAVE variants.

Do Systemair SAVE VTR filters need replacing more often in Estonian winters?

Often yes. In the heating season the SAVE unit runs continuously to recover heat, and its defrost cycles and higher fan speeds push more air – and more fine soot from heating – through the supply filter than in summer. The standard 3–6 month interval still applies, but between November and March it's worth checking the filters after about 2–3 months and replacing them earlier if airflow weakens or the control panel shows a filter warning. Changing both filters in the set at the same time keeps the unit balanced.

What filter classes do Vallox MVHR units use?

Most Vallox filter sets are three-piece G4+G4+F7 sets: two coarse G4 filters that protect the heat exchanger, plus a fine F7 (ePM1) filter for the supply air. Some older ILMAVA models use different combinations, such as G1+G1+G4 or G4+M5+F7, so match your set by model or by the Vallox filter set number.

Do all ValloPlus models use the same size filters, or does the size depend on airflow?

No. Each ValloPlus size takes its own filter set: ValloPlus 270 uses set No. 27, ValloPlus 350 No. 22/24, ValloPlus 510 No. 28 and ValloPlus 850 No. 29. Match by the model name on your unit's label.

What does the filter notification on the Vallox control panel mean?

Vallox's digital controllers assess filter contamination based on one or two indicators:

The number of operating hours elapsed
On some models, the pressure difference across the filter

This is a useful reminder, but it's also worth checking the filter visually and assessing airflow manually, especially in the first year after a new unit is installed, when the actual rate of contamination isn't yet known.

Which Vallox models (90 SE, 101 MV, 110 MV, ValloPlus 350/850) does your filter range cover?

We stock filter sets for Vallox's residential range — ValloPlus 270, 350, 510 and 850, numbered Vallox models such as 096, 110, 145 and 245 MV, Digit, TSK Multi and older ILMAVA units — widely installed across Finland and the wider Nordic market. The model name is printed on the unit's label.

What is the Vallox filter set number, and where do I use it?

Vallox groups its filters into numbered sets — for example, set No. 27 fits the Vallox 096 and ValloPlus 270, and set No. 28 fits the Vallox 145 and ValloPlus 510. Our product titles include the set number next to the model names, so if you know your set number you can match it directly. If not, find the model name on the unit's label and search by that.

Vallox is a Finnish brand that’s very common in Estonia – do you keep Vallox filters in stock?

Yes. Vallox is one of the most widely installed MVHR brands in Estonian homes, so we keep filter sets for the most popular models – such as Vallox 90 SE, 101 MV, 110 MV and the ValloPlus series – in stock at all times. In-stock sets are dispatched within 1–2 business days and delivered throughout Estonia via Omniva, SmartPost and DPD, with free delivery on orders from €100. Vallox filters are sold as complete sets (usually two G4 filters and one F7 filter), so you only need to check the exact model name before ordering.

Which Wolf CWL MVHR models (CWL-180, CWL-300/400, CWL-F-150, CWL-F/T-300) does your filter catalogue cover?

We supply filter sets for Wolf's CWL Excellent range — CWL-180, CWL-300/400, CWL-F-150 and CWL-F/T-300 Excellent — the German manufacturer's main residential MVHR line, often installed alongside Wolf heating systems. The model name is printed on the unit's label.

What filter classes are standard in Wolf CWL units?

It depends on the model. For each CWL unit we stock two versions:

CWL-300/400 Excellent — G3+G3, or G3+F7
CWL-180 Excellent — G3+G3, or G3+M6
CWL-F-150 and CWL-F/T-300 Excellent — G4+G4, or G4+F7

The version with the finer supply filter (F7 or M6) is the better choice for pollen and fine dust.

Does pairing a Wolf CWL unit with a Wolf heating system change how often filters need maintenance?

From a filter-maintenance perspective, ventilation and heating functions operate independently, but in combined Wolf systems the recovery unit often runs continuously to support overall home climate control. Because of this, it's worth checking CWL filters towards the shorter end of the standard 3–6 month interval rather than waiting for the maximum period. This is especially relevant in winter, when ventilation intensity combined with heating tends to be higher than in summer.

Do smaller and larger Wolf CWL units use the same filter?

No — filter sizes depend on the model. The CWL-300 and CWL-400 Excellent share one set, while the CWL-180, CWL-F-150 and CWL-F/T-300 each take their own. Confirm your exact CWL variant on the unit's label before ordering, since the series name alone doesn't guarantee a matching size.

What filter classes are used in the different Zehnder ComfoAir models?

Zehnder ComfoAir units use two filter classes:

G4 (ISO Coarse) — protects the heat exchanger; used on the extract side
F7 (ePM1) — for the supply air, capturing fine dust and pollen

For most ComfoAir models we stock both a G4+F7 set and a G4+G4 set. The G4+F7 set is the better choice for allergy sufferers and homes near busy roads.

Does using a compatible Wolf CWL filter instead of an original affect the warranty?

No. The filter is a consumable part, not a structural component, so using a correctly sized, correctly classed compatible filter does not affect the warranty on the CWL unit's heat exchanger, fans or electronics – that warranty covers manufacturing defects, not the brand of filter you fit. What matters is that the compatible filter matches the original's dimensions and filtration class (G3 or G4, combined with G3, G4, M6 or F7 depending on the CWL model) so airflow and pressure drop stay within the unit's design range.

How do I find the right filter for my Zehnder ComfoAir unit (160, 180, 200, 350, 375, 550, Q350)?

Find the exact model on the unit's front panel — for example ComfoAir Q350, Q450 or Q600, ComfoAir 350/500/550, ComfoD 350/450/550 or Zehnder EVO. That is the fastest way to match the correct filter set in our catalogue. If the label is missing, measuring the extract and supply filters directly identifies the right size just as reliably.

Can I order a whole year’s supply of Wolf CWL filters at once?

Yes, ordering a full season's or even a year's worth of CWL filters in one go is a common choice, especially for those who already have a maintenance schedule for their Wolf heating system and want to plan everything together. Ordering several sets at once usually brings the per-unit price down compared to buying one at a time. All you need to do is specify your exact CWL model code so that every filter in the set fits without any issues.

Do the Q350, Q450 and Q600 models use the same size filters?

Yes. The ComfoAir Q350, Q450 and Q600 — and the ComfoAir E350 — all take the same filter set, available as G4+F7, G4+G4 or an activated carbon version. Older ComfoAir models (70, 160, 180, 200, standard 300/375 and 350/500/550) each take a different size, so check your model on the front panel before ordering.

Can I replace Zehnder ComfoAir Q filters myself?

Yes – filter replacement in ComfoAir Q units is designed as a user task. Switch the unit off, open the front panel, pull out the two filters (extract and supply), and insert the new ones in the same positions, following the airflow arrow on the filter frame. Close the panel, switch the unit back on and reset the filter reminder on the control panel or in the ComfoControl app, so the next reminder is timed correctly. No tools or technician are needed, and the job takes only a few minutes. For older ComfoAir models (160, 200, 350, 550) the procedure is similar, though the filter compartment may be at the side or top of the unit.

Why do Zehnder ComfoAir filters need to be checked more often during pollen season?

Because the F7-class supply-air filter is specifically designed to capture fine airborne particles, including pollen, it fills up faster in spring and early summer than during the rest of the year. Even while keeping to the standard 3–6 month replacement interval, it's worth visually checking the filter's condition monthly during pollen season — this helps maintain stable airflow and prevents allergy symptoms from worsening indoors.

Where in Estonia is the best place to buy Zehnder MVHR filters — original or compatible?

Both original and correctly chosen compatible filters work equally effectively, provided the filter class (G4 or F7) and exact dimensions match — both types are made to the same ISO 16890 standard. When ordering online, the most important thing is to check your ComfoAir or Q model code in advance so the filter is delivered without errors. Compatible filters are typically noticeably cheaper than original Zehnder products, which is why many buyers choose them as a more economical yet equally effective alternative.

What filter class is used in Airobot heat recovery units?

Every Airobot filter set we stock — for the L, L5, S1/S2, V3 and V8 — uses the same two-stage combination:

Extract side — M5 filter
Supply side — finer F7 (ePM1) filter

Airobot units adjust airflow automatically from their CO2 and humidity readings, so filters can load up faster during busy periods such as parties, cooking or humid weather. Check them a little more often than the usual 3–6 month interval at those times.

Are the Airobot filters you sell original?

Yes. All the Airobot filter sets we stock are original M5+F7 sets for the L, L5, S1/S2, V3 and V8, so the size and filter class match what the unit was supplied with. Ordering two or more sets at once gives you a bulk discount, which makes it easy to keep a spare set at home for the next change.

Does a clogged filter throw off Airobot’s smart sensors?

Yes. Airobot's demand-controlled algorithm makes its operating decisions based on stable airflow readings, which it interprets together with the CO2 and humidity sensor data. A clogged filter reduces airflow and can force the system to run the fan at a higher speed than actually needed – increasing noise and energy use. Replacing filters on a regular schedule keeps the smart-control logic accurate and lets the unit run on less electricity.

How do I know which filters fit my Airobot unit?

Check the model name on the unit's rating label. We stock original M5+F7 filter sets for the Airobot L, L5, S1/S2, V3 and V8, and each model takes its own size — for example, the L set measures 269×236×46 mm and the L5 set 305×248×92 mm. If the label has worn off, measure the length, width and depth of your current filters in millimetres and match them against the dimensions on each product page.

Airobot is an Estonian brand – do you keep Airobot filters in stock in Estonia?

Yes. Airobot is an Estonian manufacturer and its heat recovery units are especially common in Estonian homes, so we keep original M5+F7 filter sets for the Airobot L, L5, S1/S2, V3 and V8 in stock. In-stock sets are dispatched within 1–2 business days and delivered throughout Estonia via Omniva, SmartPost and DPD, with free delivery on orders from €100. Each model takes its own filter size, so check the model name on the unit's rating label before ordering.

Which Atrea heat recovery units do the filters you sell fit?

We stock original filters for the Atrea Duplex range, including Duplex EC5/ECV5, Easy, Easy2, Pro, Pro-V and Slim units. Filters for the EC5/ECV5 and Easy models come in packs of 10 of one class (G4 or F7), while Easy2, Pro, Pro-V and Slim filters come as sets of two. If you know your unit is a Duplex but are unsure of the exact variant, measure the length, width and depth of the current filter in millimetres and match it on the product page.

How often do Atrea Duplex filters need to be replaced?

Atrea's manufacturer recommendations for Duplex filters cover a few points:

check the filters every 3 months
replace them at least twice a year, even if they look clean
watch for the maintenance reminder shown on the RD5/RD6 controller display, which is triggered once the pressure drop across the filter increases

Following this on-screen reminder rather than a fixed calendar date gives a more accurate result, matched to the actual air quality conditions in your space.

Can I wash and reuse my Airobot filters?

No. The pleated M5 and F7 filters in Airobot units are not designed to be washed or vacuumed. Water and suction damage the filter media and loosen the dust it has already trapped, so a cleaned filter lets more fine particles through and can restrict airflow unevenly. Replace both filters as a set instead.

Can I use a higher-grade filter in my Atrea Duplex unit to reduce allergies?

On most Duplex models, yes. Atrea filters come in two classes: G4 for coarse dust and F7 (ePM1) for fine dust and pollen. For most EC5/ECV5, Easy, Easy2, Pro and Pro-V sizes we stock both classes in the same size, so you can switch from G4 to F7 without any modification — one of the simplest upgrades for households with pollen or dust allergies. A few compact models, such as the Duplex Slim 150, Easy2 200 and Pro-V 160, are available in G4 only.

Why are some Atrea Duplex filters sold in packs of 10?

Duplex EC5/ECV5 and Duplex Easy units use single filters, and Atrea supplies them in packs of 10 pieces of one class — G4 or F7. A pack covers several replacements, so check how many filters your unit takes and order G4 and F7 packs separately if you run a different class on each side. Newer models such as Duplex Pro, Pro-V and Easy2 use matched sets of two filters instead.

Why might two Blauberg units with a similar name need different filters?

Blauberg uses similar model names across many sizes and versions — for example Komfort EC SB 250E, SB 350 and SB 550, or Roto EC SE 200 to SE 600 — and each size takes its own filter set. If a replacement doesn't fit despite a similar name, compare the full model code and measure the physical filter dimensions rather than relying on the series name alone.

How much can I save by buying compatible Blauberg filters instead of original ones?

Our ISO 16890 certified compatible filters for Blauberg units usually cost noticeably less than the manufacturer's original filters, since you're not paying extra for branded packaging. The filtration class, dimensions and airflow figures match the OEM specification, so you get the savings without any drop in indoor air quality or heat recovery performance.

Do I need tools or a technician to replace filters in a Blauberg unit?

No – most residential Blauberg heat recovery units are designed so the filters can be accessed without any tools:

switch the unit off
open the front or side cover by hand
pull out the old filter
slide in the new filter and close the cover

The whole process usually takes just a few minutes and doesn't require calling in an installer – any homeowner or apartment resident can change the filters themselves.

Do you deliver Blauberg filters to parcel lockers in Estonia (Omniva, SmartPost, DPD)?

Yes. Blauberg replacement filters are light and compact, so they fit easily in Omniva, SmartPost and DPD parcel lockers – just pick the most convenient locker at checkout. In-stock filters are dispatched within 1–2 business days, and delivery is free on orders from €100, so ordering two or three sets at once usually makes sense. Before ordering, check the exact model name on the unit, since Blauberg uses similar model names for many sizes and each size takes its own filter set.

Where can I buy Brink filters in Estonia, and do they fit the Renovent Excellent 300 and Flair 325 models?

We keep filters for all the main Brink series in stock, including Renovent Excellent 300, Renovent Excellent 400 and Flair 325, and ship them all over Estonia. For each model, the filters are matched to the unit's exact dimensions, so it's important to state the full model name at the time of ordering (e.g. "Flair 325", not just "Flair"), since different variants of the same name can differ in filter size or configuration.

Which Brink series do you supply filters for – Renovent Excellent, Renovent Sky or Flair?

We carry replacement filter sets for Brink's most common residential lines:

Flair (225, 325/400, 450/600)
Renovent Excellent (180, 300/400/500)
Renovent Sky (150/200, 300)
Renovent HR (250/325, with or without bypass)

The model name is usually printed on a label inside the front cover, next to the filter compartment. If the label isn't visible, send us the exact model number or the filter dimensions and we'll find the right set for you.

What should I do if the Atrea filter I ordered doesn’t fit my Duplex unit?

If the filter you ordered doesn't match your Duplex variant, we accept returns or exchanges as long as the filter is unused and still in its original packaging. The simplest way to avoid this situation in the first place is to send us the exact Duplex model code, or the filter's own dimensions, before ordering – this way you avoid a mismatch and the unnecessary wait involved in a return.

My Atrea Duplex is installed in a summer house that’s only used seasonally – how should I handle filter changes?

For a seasonally used house, plan the filter change around the season rather than the calendar. Fit fresh filters when you open the house in spring, and check them again before closing it for winter – if the unit has been running on a low setting through a damp autumn, the filters may have absorbed moisture and are best replaced rather than left in over winter. If the unit is switched off for months, remove the old filters before the standstill and install new ones when you restart it, so the first air that reaches the rooms doesn't pass through a damp, dusty filter. Store spare Duplex filters in their packaging in a dry room, not in an unheated outbuilding.

What filter class is standard in Blauberg units?

The Blauberg Komfort filter sets we stock use a G4 filter on the extract side and an F7 (ePM1) filter on the supply side. G4 protects the heat exchanger from coarse dust, while F7 captures fine dust and pollen before the air reaches your rooms.

How do I find the right filter for my Blauberg heat recovery unit?

Blauberg produces a broad range of ventilation units, so start with the model code on the unit's rating plate. We stock filter sets for the Blauberg Komfort range — including Komfort EC SB, EC S5B, EC DB, D5B180E, SBE 250E and the Komfort Roto EC models. If the plate is missing, measure your current filters in millimetres to narrow it down in our catalogue.

Do all Renovent Excellent, Renovent Sky and Flair models use the same size filter?

No — filter dimensions differ between the Renovent Excellent, Renovent Sky, Renovent HR and Flair series, and often between sizes within a series (for example, Flair 225, 325/400 and 450/600 each take their own set). Always match by your exact series and model, or measure your current filter directly, rather than assuming sizes carry across the Brink range.

How fast do you deliver Brink filters?

We ship Brink filters all over Estonia, and most orders reach the customer within a few business days. Since a clogged filter gradually reduces airflow and can make the heat recovery unit run less efficiently, we recommend ordering a new set a little before the planned replacement date is due – this way you avoid a period where the unit is running with an overly saturated filter.

Can I order Brink filters for a whole year at once?

Yes. Depending on your replacement interval, a year's supply for a Brink Renovent or Flair unit is usually 2–4 filter sets, which comfortably exceeds the €100 threshold for free delivery. Filters keep for a year or more if stored in their original packaging in a dry, dust-free place away from direct sunlight. Having spare sets at home means you can replace the filters as soon as the unit's filter indicator comes on, instead of running on a saturated filter while waiting for a delivery.

What filter class is recommended for Brink units?

It depends on the series. The Brink filter sets we stock come in these combinations:

Flair and Renovent Sky — G4+G4, or G4+F7 with a fine F7 (ePM1) supply filter
Renovent Excellent 300/400/500 — G3+G3, or G3+F7
Renovent Excellent 180 and Renovent HR — G3+G3, or G3+M6

Choose the version with the finer supply filter (F7 or M6) for better protection against pollen and fine dust, for example near a busy road. The Flair 225 is available as G4+G4 only.

How do I find the right filter for my Brofer heat recovery unit?

Start with the model code on the unit's label — we stock filter sets for the Brofer RDCD25(SK), RDCD35SH, RDCD40SK/RDCD50SK, RDCD50SH and LQR280. If the label isn't legible, measure the extract and supply filters directly (length × width × depth in mm) and match them against the sizes on our product pages.

How often do Brofer filters need to be replaced?

For Brofer units, the standard recommended interval is 3–6 months, and during the first year after installation it's worth checking the filters more often to see how quickly they clog in your particular environment. For households with pets, or where renovation or construction work is going on nearby, it's advisable to aim for the shorter end of the interval – around 3 months – rather than the full six.

How should I store spare Brofer filters so they don’t lose their properties before installation?

To keep unopened Brofer filters fit for installation, follow a few simple rules:

leave them in the original packaging until you're ready to install them
store them in a dry, room-temperature space
keep them away from direct sunlight and moisture

Filter material that's left unwrapped for a long time can absorb ambient moisture, which slightly reduces its ability to trap dust even before the filter is put into use.

What filter classes fit Brofer units?

Brofer units use G4 filters to protect the heat exchanger. For the RDCD models we stock two versions: a G4+G4 set, or a three-filter G4+G4+F7 set that adds a fine F7 (ePM1) supply filter for pollen and fine dust. The LQR280 is available as a G4+G4 set.

Does using a compatible filter instead of an original one void the warranty on my Brofer unit?

Using a correctly sized, ISO 16890 compliant compatible filter does not void the mechanical or heat exchanger warranty on a Brofer unit, since the filter is considered a normal, regularly replaced consumable part rather than a structural component of the unit. Manufacturer warranty terms generally only require that the filter match the specified class and dimensions – not that it carry the original brand name.

What should I do if the Brofer filter I ordered turns out to be the wrong size?

You can return it. We accept returns of unused, undamaged filters in their original packaging. To avoid the situation, measure the old filter in millimetres – length, width and thickness – before ordering and compare it with the dimensions in our catalogue, or send us a photo of the unit's label. Brofer units are sold in several sizes and configurations, so the dimensions are a more reliable guide than the series name alone.

Does Defro make MVHR units, or only heating equipment?

Defro is best known for biomass boilers, but it also makes residential ventilation units with heat recovery, often installed alongside Defro heating equipment. We stock filter sets for the Defro DRX V and OPTI V units, which share the same filter size.

What filter type does a Defro DRX V or OPTI V unit use?

Defro DRX V and OPTI V units use an M5+M5 filter set — one M5 filter on the extract side to protect the heat exchanger and one on the supply side. We stock it as an original set and as a lower-cost house brand set, plus an original set with an activated carbon filter for odour control.

How often do Defro DRX V / OPTI V filters need to be changed, and is it worth buying a year’s supply at once?

The usual recommendation is to check the filters every 3 months and replace them when you notice reduced airflow or increased noise – typically 2–4 times a year, depending on outdoor air pollution and the number of occupants. Buying a year's supply (2–4 sets) at once is a convenient way to make sure you're never caught without a filter at the wrong moment, and buying several sets together usually works out to a lower price per unit than buying one at a time.

Can Defro filters be replaced without a technician?

Yes. The filters in Defro DRX V and OPTI V units sit behind the filter cover and slide out without tools, so you can change them yourself in a few minutes. Switch the unit off before opening the cover and check the airflow arrows on the new filters before inserting them.

Which Electrolux models (e.g. EPVS-200, EPVS-350) do you sell filters for?

We stock filter sets for the Electrolux EPVS-200, EPVS-350 and EPVS-450 and the ERVX-150/250 and ERVX-350 ventilation units, which are most common in the Nordic and Baltic markets. If your unit's model plate is hard to read, filter dimensions are the most dependable way to confirm the right match.

Is there an activated carbon filter option if the Defro DRX V / OPTI V unit is installed next to a biomass boiler?

Yes. We stock an original Defro DRX V / OPTI V activated carbon set (M5+M5 AC). The carbon layer helps absorb smoke and other odours drawn into the fresh-air intake — for example from a nearby wood burner or biomass boiler — while still filtering dust at M5 level. It replaces the standard set and fits in the same two slots.

Are Electrolux ventilation filters the same as filters for other Electrolux appliances?

No – Electrolux is a large brand spanning many product categories, so filters for home MVHR (heat recovery ventilation) units are completely different from the filters used in other Electrolux products, such as:

vacuum cleaners
kitchen range hoods
air purifiers

When looking for the right filter, go specifically by your MVHR unit's model (e.g. the EPVS series) rather than a generic Electrolux household appliance filter – they are not interchangeable in either size or mounting.

Defro is a Polish brand – is it hard to get Defro filters in Estonia?

No. We stock the Defro DRX V / OPTI V filter sets – the original M5+M5 set, a lower-cost house brand M5+M5 set and the original activated carbon set – so there's no need to order from Poland or wait for the manufacturer's own delivery. In-stock filters are dispatched within 1–2 business days and delivered throughout Estonia via Omniva, SmartPost and DPD; only clearly marked made-to-order items have a longer lead time of 5–10 business days. Check the exact model on the unit's label before ordering, or measure the old filter, so the replacement matches your unit precisely.

Which filter class should I choose for an Electrolux MVHR unit?

The Electrolux EPVS and ERVX filter sets we stock are G4+G4 — a G4 filter on both the supply and extract side, which protects the unit and its heat exchanger from coarse dust.

Why are original Electrolux filters more expensive, and do compatible alternatives work just as well?

Original-branded filters carry a premium that comes largely from brand packaging and distribution rather than filtration performance. Our house brand sets for Electrolux EPVS and ERVX units are made to the same G4 class and cut to identical dimensions, so fit and airflow are unaffected.

How do I identify my Ensy MVHR unit (e.g. AHU 300) to order filters?

Ensy is a Norwegian ventilation manufacturer. We stock filter sets for its InoVent AHU range — AHU-200H/V, 300BH/BV, 300HH/HV, 350BH/BV, 400BH/BV, 400HH/HV and 700BH/BV. The model label is usually near the service hatch or filter compartment; if it isn't legible, measure your current filters to find the correct replacement.

How often should I change the filters in an Electrolux EPVS or ERVX unit?

Check them every 3 months and replace the set at least every 6 months. Change them sooner if you live near a busy road or construction site, keep pets, or notice weaker airflow or more noise from the unit — all signs that the G4 filters are clogging up.

What filter class is standard in Ensy MVHR units?

The Ensy InoVent AHU filter sets we stock are F7+F7 — a fine F7 (ePM1) filter on both the supply and extract side. That gives strong protection against fine dust and pollen and keeps the heat exchanger clean.

Can I buy Electrolux MVHR filters for a company or apartment association with an invoice?

Yes. An invoice is sent automatically by e-mail after every order, and on request we can also issue a prepayment invoice, with the goods dispatched once payment is received. Companies with a valid EU VAT number see prices in the cart automatically without VAT (0%) once the number has been verified. If you're ordering more than four filter sets – for example for several apartments or an apartment association with multiple Electrolux EPVS units – contact us first and we'll offer an additional discount tailored to the quantity.

Where can I find the Ensy MVHR user manual, and when does it say to change the filters?

Ensy MVHR user manuals are usually available on the manufacturer's website by specific model (e.g. the AHU 300 ceiling or floor-standing variant), and they specify the recommended filter check interval as well as what the control panel indicator means when it reminds you to change the filter. If you can't find the manual, or it's not in Estonian, follow the general rule of thumb – check the filters every 3 months and replace them sooner if you notice weaker airflow or increased noise.

How do I find the right filter for my MVHR unit?

To find the correct filter for your MVHR unit, you first need to identify the brand and model of your system. You can usually find this information on a label attached to the unit itself. Alternatively, consult the technical data in the maintenance manual.

If you’re unsure about the brand or model, there’s another way to find the right filter: remove the existing filter and measure its length, width, and height. Then, search by size in our online shop. Our filter listings include detailed specifications to help you match the right one.

If you're still not sure, feel free to contact us - send us the filter’s measurements, photos, or any other details, and we’ll be happy to help you find the right match.

How often do Ensy filters need to be changed?

The usual recommendation is to check Ensy filters every 3–6 months, and to replace them when the control panel shows a warning or you notice weaker airflow or a stronger smell indoors. During the cold season, when the MVHR unit works harder to recover heat, the filters can clog somewhat faster, so it's worth checking them earlier than your usual schedule in winter. For summer houses or rooms visited only occasionally, it's convenient to order several sets at once – multi-set orders come at a lower price – so the next set is already at hand.

How do I replace the filters in my MVHR? Where can I find guides and manuals?

Replacing filters is generally a simple, do-it-yourself task with no special tools required. Most of our filters come with detailed manuals or video instructions, available in the “How to change” tab on each product page. Simply find your filter and check that section for step-by-step guidance.

Original Ensy filter or a compatible alternative – is it worth choosing the cheaper option?

Compatible Ensy filters are made to the same F7 filtration class and identical dimensions as the originals, so air cleaning efficiency and fit remain the same. The difference is essentially just price – original Ensy-branded filters are usually more expensive due to packaging and distribution through official dealers, while a compatible alternative lets you save money, especially if you replace filters several times a year. The main thing is to check that the alternative matches the exact dimensions and class for your specific AHU model.

Ensy is a Norwegian brand – do the same replacement intervals apply in the Estonian climate?

Broadly yes. Ensy units are designed for Nordic conditions, and Estonia's climate is similar enough that the manufacturer's 3–6 month interval is a good starting point. Cold Estonian winters mean the unit runs continuously to recover heat, and outdoor air in the heating season carries more soot and fine particles, so filters usually clog faster between November and March than in summer. Check the filters every 3 months in winter and replace them as soon as airflow weakens or the control panel shows a filter reminder.

How often should I replace the filters in my MVHR?

We recommend replacing the filters every 3-6 months, to ensure optimal air quality and system performance.

However, replacement frequency may vary depending on factors such as:

Air pollution levels (e.g. urban vs rural areas);
Allergies or respiratory sensitivities;
Indoor pets or smoking;
Dust from nearby construction sites.

If your system includes a filter change indicator, follow its alerts. Otherwise, check the filters visually – if they appear very dirty or clogged, it's time to replace them.

Which Flexit models (Nordic, UNI, Econordic, SL4R) do you sell filters for?

We supply filter sets for Flexit's most widely used residential lines — Nordic S2/S3, S4 and CL2/CL3/CL4, UNI 2, UNI 3 and UNI 4, Econordic W4/WH4 and SL4R — common across Norway and the other Nordic countries. For Nordic and UNI units you can choose between Flexit originals and our house brand. The model designation is usually printed on the label on the front panel.

What filter class does Flexit use in its Nordic and UNI units?

Our house brand Flexit sets are F7+F7 — a fine F7 (ePM1) filter on both the supply and extract side — and the Econordic W4/WH4 and SL4R originals are F7+F7 as well. That protects the heat exchanger and gives strong filtration of fine dust and pollen in the incoming air.

How do I replace the filter myself in a Flexit SL4R or similar model?

The filter compartment on Flexit units is reached through the front cover or filter hatch, usually without tools. Switch the unit off before opening it, remove the old filters and check the airflow direction arrow on the new filters' frames, then insert them the same way and close the cover. If your model has a filter reminder, reset it afterwards. If you're unsure of the exact steps for your model (e.g. SL4R), follow the procedure in the manufacturer's user manual.

What is the difference between G3, G4, M5, M6, F7 class filters? What filter class do I need?

Filter class refers to the size and quantity of airborne particles a filter can capture. In general, the higher the classification, the more effectively the filter removes fine particles such as pollen, dust, and other pollutants from the air.

For incoming outdoor air, it’s generally recommended to use higher-class filters. However, we always suggest following the manufacturer’s guidance and using the specific filter sets outlined in your unit’s eco-commissioning documentation.

For more information, take a look at our comprehensive guide to filter classes for heat recovery units.

Do Flexit filters for Estonian homes need a special cold-climate version?

No. Flexit's Nordic units are built for cold climates, but that is handled by the unit itself – the heat exchanger, defrost logic and housing – not by the filter. Standard F7 (ePM1) class filters of the correct dimensions are exactly what the unit needs in Estonian winters too. What does change in winter is the loading rate: the unit runs harder and outdoor air contains more soot from heating, so check the filters a little earlier than usual rather than looking for a special low-temperature filter.

Why do Flexit filters often need to be changed more frequently in winter?

Flexit heat exchangers are optimised to work in sub-zero temperatures, so during the cold season the unit often runs at a higher and steadier airflow to maintain heat recovery efficiency. Because of this more intensive operation, filters can fill up somewhat faster than in the warmer months, so it's worth doing an extra check in the middle of winter rather than waiting for your usual schedule. In Norwegian this is called “filterbytte” – filter changing – and the term is often mentioned in Flexit user manuals as well.

Can I order Flexit filters in bulk for a homeowners’ association or several apartments?

Yes, we accept wholesale orders:

for apartment building homeowners' associations
for managers overseeing several buildings
for landlords with multiple Flexit units

A larger discount per unit applies above a certain quantity. Send us the models of your units and the quantity needed – we'll prepare a consolidated order and arrange a convenient delivery schedule, so there's always enough filters for every MVHR unit in the building.

Why don’t I see the name “Holtop” on my unit, even though I found the filters here?

Holtop is one of the world's largest manufacturers of heat exchanger cores and OEM components for MVHR units of all kinds, and its parts are used in many other brands' or regional manufacturers' units sold under an entirely different name. If you see a Holtop part number on your unit's core, fan block, or filter holder, even though the housing is labelled with a different brand, our Holtop filter listing is very likely to be an exact match.

Does using a filter matching the Holtop specification affect my unit’s warranty?

No – using a correctly sized filter that matches your unit's Holtop filtration class specification does not affect the warranty on the heat exchanger core or fan block, since that warranty covers manufacturing defects, not which brand of filter you use. What matters almost always is the correct size and filtration class, not the specific filter brand on the box.

What filter class do your Holtop filter sets use?

The Holtop filter sets we stock — for the Eco-Smart ERV 2.5, Eco-Smart ERV 3.5 and XHBQ-D5 — are G3+G3: a coarse G3 filter on both the supply and extract side that protects the heat exchanger core from dust. They are made in our house brand to the original dimensions.

How do I measure the filter if I can’t find the exact Holtop model in the catalogue?

Remove the filter and measure three dimensions in millimetres:

length
width
thickness

Holtop manufactures its filter holders to a fairly standardised set of sizes across its entire product line, so an exact dimensional match will almost always help you find the right replacement, even if the specific model name can't be determined.

How often should filters be changed in a Holtop-based unit?

The same rule applies as for most residential MVHR units: check the filters every 3 months and replace them at least every 6 months. Since private-label units built on a Holtop core often have no filter reminder, or one that isn't calibrated to your conditions, a fixed calendar interval is the safest approach. Homes near busy roads, with pets or with allergy sufferers should lean towards 3 months, and during the heating season or the spring pollen season it's worth taking a look at the filters even earlier.

How should I describe my private-label unit when asking you which Holtop filter fits?

Three things help us identify the right filter quickly:

a photo of the data plate or sticker on the unit, even if it shows a private-label brand rather than Holtop
the dimensions of the old filter in millimetres – length, width and thickness
the filter class printed on the old filter's frame, if visible (e.g. G4, M5, F7)

With those details we can match the filter to the Holtop core inside your unit, regardless of the brand name on the outside, and confirm the correct size before you order.

My Itho Daalderop HRU ECO filter indicator is on — what should I do?

The filter indicator on HRU ECO units is a maintenance reminder. Check the filters, fit a new set if they are dirty — which they usually are after 3–6 months — and reset the indicator as described in your manual. Resetting it without changing the filters only postpones the reminder while airflow keeps dropping.

Which filter class fits the Itho Daalderop HRU ECO 350?

For each HRU ECO size we stock two original sets:

G4+G4 — coarse filters on both sides, the standard option
F7+F7 — fine F7 (ePM1) filters that also catch pollen and fine dust

The F7 set is the better choice for allergy sufferers or homes near busy roads.

Which Itho Daalderop heat recovery units do you have filters for?

We stock original filter sets for the Itho Daalderop HRU ECO range — HRU ECO 150/200 and HRU ECO 350 — one of the most widely installed balanced ventilation units in Dutch new-build housing. The model code is usually printed on a sticker inside the unit's front cover.

Do the HRU ECO 150/200 and HRU ECO 350 use the same filters?

No. The HRU ECO 150 and 200 share one filter size, while the HRU ECO 350 takes a different set. Check the model code on the sticker inside the front cover before ordering, then choose G4+G4 or F7+F7 in the matching size.

How do I find out the exact model of my Komfovent Domekt unit (e.g. R 400 V or R 300 V)?

The exact model code is usually shown in one of the following places:

On the data plate on the side or front of the unit, usually near the electrical connection or the control panel
On a sticker under the front cover, right next to the filter compartment
In the installation documents or on the purchase invoice

What matters is not just the series name (e.g. Domekt R) but the full code, including the power rating and letter designation (400 V C6, C6M, C8, etc.) — the exact filter size depends on it.

How fast do you deliver Itho Daalderop filters in Estonia?

Itho Daalderop is a Dutch brand and less common in Estonia than the Nordic and Baltic manufacturers, but we stock original G4+G4 and F7+F7 filter sets for the HRU ECO 150/200 and HRU ECO 350. In-stock filters are dispatched within 1–2 business days and delivered throughout Estonia via Omniva, SmartPost and DPD, with free delivery on orders from €100. Clearly marked made-to-order items have a longer lead time of 5–10 business days, so for those it's worth ordering a little before the planned replacement date.

Are filters from the Domekt, Kompakt and Verso series interchangeable?

No, generally they are not. The Komfovent Domekt R, Domekt CF, Domekt S, Domekt P, Kompakt (REGO/RECU) and Verso series all have different filter housing shapes and sizes, and even within the same series (e.g. Domekt R 300 V and Domekt R 400 V) filter dimensions differ depending on the unit's power rating. The controller version (C6, C6M, C8) can also change the dimensions within the same model. Always choose a filter based on the exact model code, not just the series name.

How do I find out the exact model of my Itho Daalderop unit?

To order the correct filters, knowing just the series name (HRU ECO) isn't enough — you need the full model code:

Open the front cover — the code is usually shown on a sticker next to the filter compartment
Check your installation documents or purchase invoice
If you can't find the code, measure the old filter (length, width, thickness) and compare it with the dimensions in our catalogue

The exact code ensures the new filter fits snugly into the housing and doesn't let unfiltered air leak in around the edges.

How often do Komfovent filters need to be replaced?

The standard recommendation for Komfovent Domekt, Kompakt and Verso units is every 3–6 months, depending on filter loading according to ISO 16890. Check filters more often if:

you have pets at home, or there is construction or renovation work nearby
a family member is sensitive to allergens, especially during the flowering season
your home is in the city, close to busy traffic streets

Many Domekt and Verso controller displays show a filter replacement reminder based on running hours or pressure drop — this is a useful signal, but not a substitute for periodic inspection, since the controller doesn't always accurately capture how dirty the filter actually is.

What’s the difference between original and compatible Komfovent filters — is it worth choosing the cheaper option?

Both options meet the same requirements, but differ in a few practical respects:

Certification — both original and our compatible filters are tested according to ISO 16890 filtration classes
Manufacturing — Komfovent makes its original filters at its own factory in Lithuania, while compatible filters are made at other EU manufacturers' factories to the same class
Price — compatible filters are usually noticeably cheaper than originals
Precision — both are cut to the exact Domekt, Verso or Kompakt housing dimensions

Using a correctly sized, correctly classed compatible filter does not affect the unit's warranty, since the filter is a consumable part, not a structural component.

Does Mitsubishi’s Lossnay technology require special filters?

No. Lossnay is the name of Mitsubishi Electric's heat-recovery ventilation line and its heat exchange element — the filters themselves are conventional G4 filters that keep dust off the Lossnay core. We stock sets for the Lossnay VL-250, VL-350 and VL-500 (originals) and the LGH-15RVX to LGH-100VX (house brand). The model number on the casing label confirms the exact size.

Which filter class is used as standard in Mitsubishi Lossnay units?

The Lossnay filter sets we stock are all G4. VL-series units and the LGH-15RVX take a set of two G4 filters, while the larger LGH-25RVX to LGH-100VX take a set of four. G4 protects the Lossnay core from coarse dust and keeps airflow steady.

What filter classes are used in Komfovent Domekt units, and which should I choose for pollen allergies?

Komfovent Domekt units typically run on a two-stage set: an M5 (ePM10) class filter on the extract side and an F7 (ePM1) class filter on the supply side, both rated to ISO 16890. For hay fever or dust allergies, the supply-side F7/ePM1 filter is the one that matters, since it captures the fine pollen and particles coming in from outside – so make sure that side is always fitted with an F7 rather than a coarser M5 filter, and replace it promptly during the spring pollen season. For most Domekt models we stock both an M5+F7 set and a simpler M5+M5 set – for allergy sufferers, choose M5+F7.

How do I replace Komfovent filters myself?

On Domekt, Verso and Kompakt units, filter replacement is designed to be tool-free:

Switch the unit off
Open the front access panel or filter compartment cover
Note the airflow direction marked on the old filter's frame
Slide out the old filter and wipe the housing if it's dusty
Insert the new filter in the same orientation, close the panel and reset the filter timer on the controller

The whole process typically takes just a few minutes.

How often do Mitsubishi Lossnay filters need to be replaced?

Lossnay units follow the standard 3–6 month interval, although many models have a built-in maintenance indicator that warns when airflow drops due to a dirty filter. It's worth treating this indicator as a useful reminder rather than the only criterion for when to replace the filter — especially in urban environments or near busy streets, where the filter gets dirty faster than the calculator suggests.

Do filters fit across different generations of Mitsubishi Lossnay units, or only within the same series?

Filter compatibility generally stays within the same series and the same housing generation, but Mitsubishi has changed internal filter dimensions in some model updates, even while keeping a similar product name (e.g. within the VL or LGH-RVX series). The safest approach is to choose a filter based on the exact model number, or, if you can't find it, to measure the old filter directly before ordering a new one.

Can I replace Mitsubishi Lossnay filters myself?

Yes – Lossnay filters are designed to be replaced by the user without tools or a technician. Switch the unit off, open the maintenance cover or slide out the filter cassette, remove the old filters and note their orientation, then fit the new ones the same way, following the airflow arrow on the frame. Close the cover and switch the unit back on; if your model has a filter reminder on the controller, reset it afterwards. Take care not to knock the Lossnay core while the cover is open – it's the most delicate part of the unit.

Why do some Lossnay filter sets contain four filters?

The larger Lossnay LGH units — LGH-25RVX, 35RVX, 50RVX, 65RVX and 100VX — take four filters in total, so our sets for these models include all four G4 filters. Change them together to keep the airflow balanced. The LGH-15RVX and the VL-series units take two filters.

I have a NIBE heat pump — does that mean I also have a NIBE ventilation unit?

Not necessarily. NIBE is best known for its heat pumps, but its ERS series ventilation units are often installed in the same house alongside a NIBE heating system — they belong to the same brand but operate independently. To identify the correct filter model, check the data plate on the ventilation unit itself, not on the heat pump.

Which filter class do NIBE ERS units use (e.g. ERS 20-250)?

The NIBE ERS 20-250 filter set we stock pairs two classes:

G4 coarse filter
F7 (ePM1) fine filter

The G4 filter keeps coarse dust off the heat exchanger, while the F7 filter cleans the incoming air of fine dust and pollen.

Can I buy the NIBE ERS supply and extract air filters together, or do I need to order them separately?

They come together. We sell the NIBE ERS 20-250 filters as a matched G4+F7 set, since both filters are normally replaced at the same time — it saves ordering, and paying for delivery, twice.

Does the filter’s condition affect the heating efficiency of a NIBE system?

Yes — in integrated NIBE systems, ventilation air quality and heat recovery work together with the heat pump to maintain the indoor climate and control energy consumption. A dirty ventilation filter reduces airflow through the heat exchanger, forcing the system to work harder to maintain the desired temperature. Regularly replacing filters helps not only air quality but also your heating bills.

What should I do if the NIBE ERS filter I ordered doesn’t fit?

Unused, undamaged filters in their original packaging can be returned. We stock the filter set for the NIBE ERS 20-250, and other ERS sizes take different filters, so to avoid a mismatch check the full model code on the unit's data plate before ordering, or measure the old supply and extract filters in millimetres. If you send us the model code or the dimensions, we'll confirm the right set before you place the order.

Where’s the best place to buy NIBE filters, and how fast is delivery?

We ship NIBE ERS filters throughout Estonia, with delivery usually taking a few business days depending on your location. Since NIBE ERS units are often installed together with a NIBE heat pump, and both systems affect your home's microclimate, it's worth keeping a spare set of filters at home — this way you'll avoid any gap in air quality while waiting for a new delivery. Before ordering, check the exact ERS model number so the filter matches your unit precisely.

How do I know which filter fits my Oxygen heat recovery unit?

The model designation is usually printed on the front cover near the filter access panel – for example X-Air C200 or Easy V400E. We stock filter sets for Oxygen Easy and X-Air units in three size groups, each with its own filter size:

C180/C180E, C200/C200E and C250
V200/V200E
V400/V400E, V500/V500E and V600

If the label is worn or missing, measure your existing filter (length, width, thickness) to confirm the right replacement.

What filter classes are used in Oxygen heat recovery units?

For each Oxygen Easy and X-Air size we stock two sets:

M5+M5 – the standard set for general dust protection
M5+F7 – with a fine F7 (ePM1) supply filter for better protection against pollen and fine particles

Both sets fit the same filter cassette without any modifications – only the filter class changes, not the size.

Do the Oxygen X-Air C200 and C200E use the same size filters?

Yes. The letter "E" in an Oxygen model name simply indicates a built-in electric heater for warming the incoming air – the unit's housing and filter compartment are identical in construction. That means the X-Air C200 and X-Air C200E use exactly the same size filters, and you can order them under either model name.

The same rule applies to the other pairs – C180/C180E, V200/V200E, V400/V400E and V500/V500E.

Is it worth choosing an equivalent filter instead of an original Oxygen one?

Yes – our equivalent filters match original Oxygen filters on all the parameters that matter:

Manufactured in the EU
Meet the same ISO 16890 filtration class standards (M5, F7)
Cut to the same dimensional tolerances

Since filters need replacing several times a year, the price difference adds up noticeably over a year, while filtration quality and airflow throughput don't suffer – which makes equivalents a rational choice for routine maintenance, not a compromise.

Do you deliver Oxygen filters throughout Estonia, including the islands?

Yes – we deliver Oxygen X-Air filters throughout Estonia via Omniva, SmartPost and DPD, including Saaremaa, Hiiumaa and the other islands. In-stock filters are dispatched within 1–2 business days; delivery times are counted in business days, and deliveries to the islands may take a day longer depending on the carrier's schedule. Delivery is free on orders from €100, so if your unit is in a summer house or far from a parcel locker, it's convenient to order two or three sets at once.

How often should Oxygen heat recovery unit filters be replaced?

The recommended standard replacement interval is 3–6 months, but the exact timing depends on the environment – in the city or near a road, dust builds up faster than in a rural area. An F7 class filter, which captures finer particles, usually needs replacing a bit more often than an M5, since its fibre clogs faster.

In spring and summer, during pollen season, it's worth checking the filter every 4–6 weeks, especially if there are people with allergies in the household.

How do I find the right filters for my Paul heat recovery unit (Climos, Novus, Focus)?

Paul heat recovery units are divided into several series – we stock filter sets for the Climos (F) 200, Novus 300/450 and Focus 200. The exact model is shown on the label on the unit's front panel, not just the series name.

The Novus 300 and Novus 450 share one filter set, while the Focus 200 and Climos (F) 200 each take their own size, so check the full model name or measure the current filter – that's the surest way to get an exact match when ordering.

What filter classes are used in Paul heat recovery units?

It depends on the model. The Paul filter sets we stock come in these combinations:

Novus 300/450 and Focus 200 — G4+G4, or G4+F7 with a fine F7 (ePM1) supply filter
Climos (F) 200 — M5+M5, or M5+F7

Because Passive House buildings get all their fresh air through the MVHR unit, the version with the F7 supply filter is usually the better choice for indoor air quality.

What is the Paul ISO Defroster DN 160 filter, and how is it different from the unit’s own filters?

The Paul ISO Defroster is a separate duct-mounted component (DN 160) rather than an internal part of the heat recovery unit itself, and it has its own filter. We stock a G4 replacement filter for the ISO Defroster DN 160.

This filter does not replace the unit's own filter set – both need changing on schedule. When ordering, go by the defroster's DN diameter rather than the heat recovery unit's model.

What is MVHR?

MVHR stands for Mechanical Ventilation with Heat Recovery. It's a ventilation system that continuously extracts polluted, stale, or humid air and supplies fresh, filtered air into the premises. As the air flows through the system, a heat exchanger transfers warmth from the outgoing air to the incoming air - without mixing the two. This helps maintain indoor air quality while reducing heating costs and energy waste.

Is it worth choosing an equivalent filter instead of an original Paul one?

Yes, as long as the filter is made to the same ISO 16890 standards and matches the original's dimensions exactly. Our equivalent Paul filters:

are manufactured in the EU from the same quality filtering fibre
are cut to the same tolerances as the original filter
fit without any modification to the housing

Since filters need to be replaced several times a year, and in a passive house they play a particularly important role in air quality, an equivalent lets you save money without reducing either filtration efficiency or the unit's operating reliability.

How often should Paul heat recovery unit filters be replaced?

The standard interval is 3–6 months, but in passive houses, where the recovery unit is the sole source of fresh air, it's recommended to check the filters more often – every 2–3 months, especially the F7 filter on the supply air side. A clogged filter not only worsens indoor air quality but also increases the load on the fan and energy consumption, since the unit has to work against greater resistance.

During pollen season (April–June), it's worth checking the filter every month.

Can I store spare Paul filters for a year without them deteriorating?

Yes. Unused filters keep their properties for a year or more as long as they're stored correctly: in their original packaging, in a dry, dust-free room, away from direct sunlight and strong odours. Avoid unheated garages, cellars or outbuildings, where humidity can affect the filter media. Since Paul units in Passive Houses rely entirely on the MVHR unit for fresh air, keeping a spare set at home means you can replace a saturated filter immediately instead of waiting for a delivery.

How do I find the right filter for my Recom heat recovery unit?

The quickest option is the model code on the front cover label. We stock filter sets for the Recom 2RT, 2SR, 3SEF, 3SR, 4RT, 4S(E), 4SR, 6S(E), 6SR, EPP2SE and EPP3SE. If the label isn't legible, measure the extract and supply filters directly and match the dimensions on our product pages.

What filter classes are used in Recom heat recovery units?

The Recom filter sets we stock are G4+F7: a G4 filter that protects the heat exchanger from coarse dust and a fine F7 (ePM1) filter that cleans the incoming air of fine dust and pollen. They are made in our house brand to the original dimensions for a precise fit.

What’s the best way to maintain my MVHR system?

In between filter replacements, it’s also a good idea to clean the inside of your unit. This helps maintain not only your health but also the performance and lifespan of your heat recovery system.

You can do this yourself by removing the filters and unscrewing the front cover. This gives you access to the heat exchanger, which can be cleaned with a vacuum or a soft cloth.

Is it worth choosing an equivalent filter instead of an original Recom one?

Yes – our equivalent Recom filters are made to the same dimensions and ISO 16890 filtration class (G4 or F7) as the original manufacturer's filters, only manufactured in the EU and at a lower price. Since filters need replacing several times a year, the price difference becomes significant over a year.

If you're unsure of the exact size, send us the model code or the filter's dimensions before ordering – we'll check the match in advance.

Can I vacuum clean my filters?

Some filters (such as wire-framed or coarse pre-filters) can be gently vacuumed to remove surface dust and extend their lifespan. If your unit's manual allows it, you can usually vacuum the filter up to three times before replacing it. Always avoid using high suction settings, and handle the filter with care to avoid damage.

How often should Recom filters be replaced?

Recom sets combine a G4 extract filter with a fine F7 supply filter, and in Recom units it's recommended to check the filters every 2–3 months and replace them once you notice reduced airflow or increased noise. The standard maximum interval is 3–6 months, but in a dusty environment or near a busy street it's worth checking more often.

Regular checks protect not only air quality but also the recovery unit's own heat exchanger from premature contamination.

Can I wash my filters?

No, MVHR filters are not designed to be washed. Washing can damage the filter material, reduce its efficiency, and affect the shape, which may lead to poor fit and airflow issues. If you're looking to remove light surface dust, it's better to gently wipe the filter with a soft, dry cloth. For optimal performance, we still recommend replacing the filters regularly.

Which Salda heat recovery unit series do you carry filters for?

We stock filters for Salda's widely installed residential lines:

RIRS series (EKO 3.0)
RIS series
Smarty series (2X, 3X, 4X and 2R)

They are especially popular in Estonia and the other Baltic and Nordic countries. The series and airflow size (e.g. RIS 400, Smarty 4X P) are printed on the unit's label – the easiest way to identify your exact model before choosing a filter set.

Why is filter replacement so important?

Clean filters are essential for both your health and the performance of your ventilation system. Over time, dust, bacteria, and fungi can accumulate in the filters, the system, and the air ducts. If the filters become saturated, your MVHR unit has to work harder to maintain airflow - using more energy and increasing your costs.

Dirty filters can also reduce indoor air quality by allowing harmful particles and microorganisms to recirculate, which may negatively affect your health and well-being.

How do I determine the exact model of my Salda Smarty unit (e.g. 2R Ver Plus)?

On Salda Smarty series units, the model code is usually made up of several parts – for example, "Smarty 2R Ver Plus" indicates the size group (2R), while "Ver Plus" marks a specific version with additional features. This whole code, not just "Smarty", is shown on the front cover or inside on the technical data plate.

Since filter size depends on the specific version, giving the exact model code when ordering lets you get the right size set straight away, without needing to measure the filter itself.

Why do my filters get dirty so quickly?

Several factors can cause your MVHR filter to become contaminated faster than expected, including both environmental conditions and the type of filter used:

Outdoor air quality: if you live near busy roads, industrial zones, or construction sites, your system may pull in higher levels of dust and pollution. In these cases, filters can become saturated in less than two months.
Filter efficiency: higher-grade filters (such as F7 or ePM1-rated) capture finer particles, which improves air quality - but they may clog more quickly due to the higher amount of trapped pollutants.
Filter quality: low-cost or poorly made filters (especially those from non-EU sources) may have higher pressure drops, reducing airflow efficiency and requiring more frequent replacement. They can also increase energy consumption over time.
System airflow rate: running the MVHR system at more powerful airflow settings means a greater volume of air moves through the filters each hour, which can lead to faster filter contamination.

If you notice filters getting dirty unusually fast, it may be worth reviewing your filter class, local air conditions, or even upgrading to a multi-stage filtration setup.

How fast do you deliver Recom filters in Estonia?

In-stock Recom filters are dispatched within 1–2 business days and delivered throughout Estonia via Omniva, SmartPost and DPD – to a parcel locker or directly to your address. Delivery is free on orders from €100. Only clearly marked made-to-order items have a longer lead time of 5–10 business days. Since a clogged filter gradually reduces airflow and efficiency, we recommend ordering the next set a little before the planned replacement date rather than after the filter warning appears.

Why does an MVHR system use two filters?

MVHR systems typically use two filters, some models may even include three or four - depending on the design and filtration requirements.

Usually one filter is used for extract air and one for supply air, each serving a different purpose:

The extract filter captures dust and particles from the indoor air as it’s removed from your home. This helps protect the internal components of the MVHR unit and reduces buildup in the ventilation system.
The supply filter cleans the outdoor air before it’s brought into your premises. This improves indoor air quality and protects your health.

Using both filters ensures that your MVHR system remains efficient while maintaining a clean and healthy indoor environment.

Do Recom filter sets include a finer F7 filter for pollen?

Yes. Every Recom set we stock is a G4+F7 set: the G4 filter protects the heat exchanger from coarse dust, and the F7 (ePM1) filter captures fine particles and pollen in the incoming air. There's no separate upgrade to order – just make sure each filter goes in its correct slot, following the markings on the frame, and replace both together.

Why do you only offer sets of 2 Blauberg filters instead of 3?

Initially, Blauberg MVHR units have three filters installed. The third filter is added temporarily during or shortly after construction to protect the main supply filter from construction dust and debris. It is intended to be removed once construction is complete and you move into the premises.

After that, the system is designed to operate efficiently with two filters: one for the extract air (stale indoor air going out) and one for the supply air (fresh air coming in). Using more than two filters during regular operation is unnecessary. So when replacing the filters, only the two main filters need to be changed.

Are the filters of the RIS and Smarty series interchangeable?

No – even within the same series, filter size depends on the unit's airflow capacity, so RIS or Smarty filters are not automatically interchangeable with each other. For example, the filter from a lower-capacity RIS model usually won't fit a larger unit in the same series.

Before ordering, always check the full model code on the unit or, if you're unsure, send us the dimensions of your current filter – that way you'll avoid having to send back the wrong size.

Why are there 3 filters in the Vallox replacement filter pack?

Vallox systems use a three-filter setup to ensure optimal air quality and protect the system. Our replacement filter set includes two G4 filters and one F7 filter.

One G4 filter captures coarse particles from the extracted indoor air, protecting the system from dust and debris buildup. The second G4 acts as a pre-filter on the supply side, trapping larger particles such as insects and debris before they reach the main F7 filter. The F7 filter performs the greatest filtration function, capturing finer particles such as dust, pollen, and allergens, thereby improving indoor air quality.

This combination helps extend the system’s lifespan and maintain efficient performance.

What filter class is used in Salda RIS and Smarty units?

It depends on the series:

Most Salda RIS and RIRS EKO 3.0 units – an M5 extract filter and a fine F7 (ePM1) supply filter; for some sizes an M5+M5 set is available too
Older RIS models differ – the RIS 400 P1/P2 5.0 takes G4+G4 and the RIS 400 VED G4+M5
Smarty 2X, 3X and 4X – a G4 extract filter with either a G4 or an F7 supply filter
Smarty 2R – M5 filters

Check your exact model before ordering – each product page shows the filter classes in that set.

Can MVHR filters help with allergies?

Yes. Using higher-grade filters (such as F7 or ePM1-rated filters) can significantly reduce allergens like pollen, dust mites, and pet dander, improving indoor air quality for allergy sufferers. Regular replacement is key to maintaining this benefit.

Is it worth choosing an equivalent filter instead of an original Salda one?

Yes – our equivalent Salda filters match the originals in filtration class (G4, M5 or F7) and exact dimensions, but are manufactured in the EU and cost less. Since filters need replacing several times a year, and the RIS and Smarty series are especially popular in Estonia, keeping equivalent filters in stock lets us deliver them faster than waiting for originals to arrive from abroad.

There's practically no difference in quality, as long as the filter is made to the same standards and fits your model exactly.

What’s the difference between EN 779 and ISO 16890 filter classes?

EN 779 and ISO 16890 are two different standards for classifying air filters. While they serve the same purpose, describing how efficiently a filter removes particles from the air, they use different testing methods and naming systems.

EN 779 (now outdated) used categories like G4, M5, F7, etc. ISO 16890, which replaced it, classifies filters based on their efficiency against specific particle sizes (PM10, PM2.5, PM1). For example, a filter that used to be called F7 under EN 779 may now be labeled as ePM1 60% under ISO 16890.

We include both classifications on our product pages to help you find the right match for your system.

My Salda unit shows a filter alarm — how do I reset it?

The filter alarm on Salda units is a reminder that the service interval has passed. Replace both filters first, then reset the filter timer from the controller — the exact menu depends on your controller type, so follow the unit's manual. Resetting the alarm without changing the filters only hides the reminder while airflow keeps dropping.

What is the difference between original and house brand products?

Original filters are made by or for the ventilation unit’s original brand, through certified production partners. They follow the brand’s specific manufacturing and packaging standards.

House brand filters, on the other hand, are made by trusted independent manufacturers who meet strict quality requirements. We work closely with our production partners and carry out our own quality control to ensure a precise fit and reliable performance. Since they’re not tied to a specific brand label, house brand filters are often more affordable - offering excellent value without compromising on quality.

What filter classes do Samsung MVHR units use?

The Samsung ERV filter sets we stock use F7 (ePM1) filters throughout: two filters for the ERV 250 and four for the ERV 350/500 and ERV 800/1000. F7 captures fine dust and pollen and keeps the heat exchanger clean.

Does Samsung make heat recovery ventilation units?

Yes. Samsung makes ERV (energy recovery ventilation) units, often installed alongside Samsung air conditioning systems. We stock house brand filter sets for the Samsung ERV 250, ERV 350/500 and ERV 800/1000. If your unit carries a Samsung nameplate, match it by model code or measure the filters directly.

How often should Samsung MVHR filters be replaced?

The standard interval is every 3–6 months, though it's worth shortening in these cases:

There are pets in the home
There are allergy sufferers in the household
Nearby construction or renovation work is increasing the amount of dust in the air

Regular replacement not only maintains air quality but also protects the unit's heat exchanger and fans from excessive strain.

How do I find the right filter if I don’t know the exact model of my Samsung MVHR unit?

First check the sticker on the unit's casing or front panel — it usually shows the full model code. If there's no sticker or it's been peeled off, remove the old filter and simply measure its width, height and thickness in millimetres — these dimensions let you find an accurate match even without knowing the model name. Since Samsung recovery units are found in Estonia less often than more popular MVHR brands, we recommend confirming the dimensions before ordering so the filter can be sent out without delays.

Do you also supply filters for Samsung ERV units installed in offices and commercial spaces in Estonia?

Yes. Samsung energy-recovery ventilation units are more often found in offices, shops and commercial buildings than in homes, and we supply filters for them on the same terms. An invoice is sent automatically after every order, companies with a valid EU VAT number see prices in the cart without VAT (0%), and for orders of more than four filter sets we offer additional discounts – contact us with the model codes and quantities. If the model code isn't visible, the dimensions of the existing filter are enough to find a match.

Does a compatible (non-original) filter work just as well as the original for a Samsung MVHR unit?

Yes — if the filter class (F7) and dimensions match those specified by the manufacturer, a compatible filter filters the air just as effectively as the original, since both are made to the same ISO 16890 standard. The only real difference is price: because Samsung isn't a major manufacturer in this segment, its original filters can sometimes be harder to find and more expensive. The most important thing is to accurately identify your unit's model and filter dimensions before ordering.

How often should SAVE VTR or VSR filters be replaced?

The standard interval is every 3–6 months, depending on air pollution, pets and the number of people in the household. Systemair SAVE units are used in both large commercial buildings and homes to the same engineering standards, so the residential filter is also designed to withstand continuous, reliable operation. Regular filter replacement maintains stable airflow and protects the heat exchanger from premature clogging, especially in the intensively used SAVE VTR 500 and VTR 700 models with higher airflow rates.

Do Systemair SAVE VTC and VTR variants use the same filter?

No. VTC and VTR are different unit designs, and each model in the SAVE range takes its own filter set — for example the VTR 300 and VTC 300 use different sets, and a VTR 300 (BF) takes a different set than a VTR 300 (PF). Check the full model code, including PF or BF, on the front panel label before ordering.

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Which Systemair SAVE models (VTR 150, 275, 300, 500, 700, VSR 200) does your filter range cover?

What filter classes are used in Systemair SAVE VTR units?

Can I order a multi-year supply of Systemair SAVE filters at once?

Do Systemair SAVE VTR filters need replacing more often in Estonian winters?

What filter classes do Vallox MVHR units use?

Do all ValloPlus models use the same size filters, or does the size depend on airflow?

What does the filter notification on the Vallox control panel mean?

Which Vallox models (90 SE, 101 MV, 110 MV, ValloPlus 350/850) does your filter range cover?

What is the Vallox filter set number, and where do I use it?

Vallox is a Finnish brand that’s very common in Estonia – do you keep Vallox filters in stock?

Which Wolf CWL MVHR models (CWL-180, CWL-300/400, CWL-F-150, CWL-F/T-300) does your filter catalogue cover?

What filter classes are standard in Wolf CWL units?

Does pairing a Wolf CWL unit with a Wolf heating system change how often filters need maintenance?

Do smaller and larger Wolf CWL units use the same filter?

What filter classes are used in the different Zehnder ComfoAir models?

Does using a compatible Wolf CWL filter instead of an original affect the warranty?

How do I find the right filter for my Zehnder ComfoAir unit (160, 180, 200, 350, 375, 550, Q350)?

Can I order a whole year’s supply of Wolf CWL filters at once?

Do the Q350, Q450 and Q600 models use the same size filters?

Can I replace Zehnder ComfoAir Q filters myself?

Why do Zehnder ComfoAir filters need to be checked more often during pollen season?

Where in Estonia is the best place to buy Zehnder MVHR filters — original or compatible?

What filter class is used in Airobot heat recovery units?

Are the Airobot filters you sell original?

Does a clogged filter throw off Airobot’s smart sensors?

How do I know which filters fit my Airobot unit?

Airobot is an Estonian brand – do you keep Airobot filters in stock in Estonia?

Which Atrea heat recovery units do the filters you sell fit?

How often do Atrea Duplex filters need to be replaced?

Can I wash and reuse my Airobot filters?

Can I use a higher-grade filter in my Atrea Duplex unit to reduce allergies?

Why are some Atrea Duplex filters sold in packs of 10?

Why might two Blauberg units with a similar name need different filters?

How much can I save by buying compatible Blauberg filters instead of original ones?

Do I need tools or a technician to replace filters in a Blauberg unit?

Do you deliver Blauberg filters to parcel lockers in Estonia (Omniva, SmartPost, DPD)?

Where can I buy Brink filters in Estonia, and do they fit the Renovent Excellent 300 and Flair 325 models?

Which Brink series do you supply filters for – Renovent Excellent, Renovent Sky or Flair?

What should I do if the Atrea filter I ordered doesn’t fit my Duplex unit?

My Atrea Duplex is installed in a summer house that’s only used seasonally – how should I handle filter changes?

What filter class is standard in Blauberg units?

How do I find the right filter for my Blauberg heat recovery unit?

Do all Renovent Excellent, Renovent Sky and Flair models use the same size filter?

How fast do you deliver Brink filters?

Can I order Brink filters for a whole year at once?

What filter class is recommended for Brink units?

How do I find the right filter for my Brofer heat recovery unit?

How often do Brofer filters need to be replaced?

How should I store spare Brofer filters so they don’t lose their properties before installation?

What filter classes fit Brofer units?

Does using a compatible filter instead of an original one void the warranty on my Brofer unit?

What should I do if the Brofer filter I ordered turns out to be the wrong size?

Does Defro make MVHR units, or only heating equipment?

What filter type does a Defro DRX V or OPTI V unit use?

How often do Defro DRX V / OPTI V filters need to be changed, and is it worth buying a year’s supply at once?

Can Defro filters be replaced without a technician?

Which Electrolux models (e.g. EPVS-200, EPVS-350) do you sell filters for?

Is there an activated carbon filter option if the Defro DRX V / OPTI V unit is installed next to a biomass boiler?

Are Electrolux ventilation filters the same as filters for other Electrolux appliances?

Defro is a Polish brand – is it hard to get Defro filters in Estonia?

Which filter class should I choose for an Electrolux MVHR unit?

Why are original Electrolux filters more expensive, and do compatible alternatives work just as well?

How do I identify my Ensy MVHR unit (e.g. AHU 300) to order filters?

How often should I change the filters in an Electrolux EPVS or ERVX unit?

What filter class is standard in Ensy MVHR units?

Can I buy Electrolux MVHR filters for a company or apartment association with an invoice?

Where can I find the Ensy MVHR user manual, and when does it say to change the filters?

How do I find the right filter for my MVHR unit?

How often do Ensy filters need to be changed?

How do I replace the filters in my MVHR? Where can I find guides and manuals?

Original Ensy filter or a compatible alternative – is it worth choosing the cheaper option?

Ensy is a Norwegian brand – do the same replacement intervals apply in the Estonian climate?

How often should I replace the filters in my MVHR?