Atrea Duplex Easy 300/400 filters

Atrea's guidance for Duplex filters covers three checkpoints:

• Check filters every 3 months
• Replace them at least twice a year, even if they still look clean
• Watch for the RD5/RD6 controller's on-screen maintenance reminder, which triggers once pressure drop across the filter rises

Following that on-screen prompt rather than a fixed calendar date gives the most accurate result for your specific air quality conditions.

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.

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.

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.

For living spaces in continuous use, Finnish design guidance applies supply air class SUP 2, and in normal outdoor air conditions (ODA 1) that translates into an ePM1 50% filter on the supply side — the class that used to be called F7. On the extract side a coarser class is enough, since its job is to protect the heat exchanger and ducts rather than to clean the air you breathe. For a Duplex unit the practical rule follows from this: keep the supply filter at the class the system was designed around. Dropping a step to save money changes what actually reaches your rooms, which is the one thing the class is there to control.

If a filter you've ordered turns out not to match your Duplex variant, we accept returns or exchanges as long as the filter is unused and in its original packaging. Sending us your exact Duplex model code or the measured filter dimensions upfront is the easiest way to avoid a mismatch in the first place.