The optional particulates filter keeps pollen and particulates such as diesel particles from entering homes. The filter is easy to replace yourself.
Bothered by hay fever? Do you live near the highway? Or in a busy city? Sensitive lungs? Then your life can be considerably more pleasant if you filter the air coming into your house. The particulates filter in Fresh-r stops even the tiniest particles.
Larger dust particles get caught by the heat exchanger. This way, the Fresh-r particulates filter lasts for a year.