I own a log home which has two units to supply heating and cooling. I am hoping to become educated by the experts from this forum. The downstairs unit is in the crawl space and the upstairs unit is in the attic. Both are extremely difficult to access. Both units have return air filters at the units. There are return air grills in our walls. My question is, can I filter the air from the existing return air grills? I'd much rather modify the return air grills then go under the house and up in the attic each time the filters need changed.
Your help is much appreciated.