Most heat recovery ventilation manufactures recommend that HRV filters be changed at least once a year, but this is subject to where you live and the conditions of air quality around your home.

If you live in a town or city or beside a busy road, air pollution tends to be greater so your HRV filters will need to be changed more often.

Best practice is to check and clean your heat recovery ventilation filters every 3 months. In city areas MVHR filters should be changed every 6 months.