Itho Daalderop HRU filters

Both options are made to fit the same HRU or WPU housing geometry and the same filtration class (usually F7):

• Original filters — manufactured to Itho Daalderop's specifications, often more expensive
• Compatible (equivalent) filters — made by other EU manufacturers to the same dimensions and ISO 16890 class, at a lower price

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

We supply filters for the two most popular Itho Daalderop series:

• HRU (including the HRU ECO and HRU ECO 150/200/350 models) — a standalone balanced ventilation unit
• WPU — ventilation integrated with a heat pump system

Both series are widely used in new-build homes in the Netherlands. You'll usually find the exact model code on a sticker under the unit's front cover, next to the filter compartment.

The HRU ECO 350 and similar HRU models usually come with two F7-class filters — one on the supply air side and one on the extract air side, although some variants use a simpler G4 filter on the extract side. F7 (ePM1) class captures fine dust and pollen, making it suitable for more sensitive households. Check the exact set (F7+F7 or F7+G4) against your specific model code, as different HRU variants can differ.

The ventilation filters themselves are maintained independently of the heat pump function, but in WPU systems the ventilation runs continuously, supporting both heating and air quality. As a result, the filters can accumulate more running hours per year than in standalone HRU units — it's worth checking them more often, closer to the 3-month mark rather than 6 months.

To order the correct filters, knowing just the series name (HRU or WPU) 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.

The usual interval for Itho Daalderop HRU units is every 3–6 months, and most models also have a filter indicator on the unit or in the app that tells you when it's time. In practice, homes near busy roads, with pets or with allergy sufferers should lean towards 3 months, while a quiet suburban home can often go 6. If the indicator comes on earlier than expected, it usually means the outdoor air has been dustier than usual – for example during the spring pollen season – rather than a fault with the unit.