Enter your room and this calculator estimates the clean-air delivery you need (at five air changes an hour), how many air changes a typical CR box would give, and whether a four- or five-filter build suits — plus a rough cost.
681 m³/h CADR, MERV-13, under 35 dB — powerful whole-home clean air — no proprietary lock-in, ships from the UK.
Check price →Use code CORSI10 for 10% off at checkout.CR box build calculator — enter your room to see the clean air you need and a suggested build.
Room length (m): width (m): height (m):
How it works
It multiplies your room volume by five (a good target air-change rate for allergy, smoke and pollution), then compares that to a well-built box's typical ~450 m3/hr. Larger rooms may need a five-filter build or two boxes. For the reasoning, see the air-changes calculator and build instructions.