Each recuperator needs to be changed every few months. Their task is to protect sensitive elements inside the device as well as to filter the air supplied to the house, room. Filters for the recuperator retain any airborne particles harmful to human health, which is why it is so important to use filters with high filtration efficiency. On average, the filters for the recuperator are replaced once every 4 months. Each recuperator has a filter on the supply and exhaust, we always exchange the set. It is a good practice to purchase two sets of filters for the recuperator in order to prevent the device from working with a clogged filter.