Holtop Eco-Smart ERV 3.5 Filters

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.

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.

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.

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.

Check the filters every 3 months and replace them at least every 6 months. Coarse G3 filters hold a lot of dust before airflow drops, so don't wait for them to look completely grey — if the unit gets louder or the air feels stuffier, change the set straight away. Vacuuming or washing G3 filters is not a substitute for replacement, as it damages the media.