markdouglas
Happy Customer
I run my dc variable speed furnace motor all winter and in the summer when the AC is on so I try to change the filter every month. I buy a box of 12 Purolator filters which are mid range, or better, quality filters. The price is good and the convenience of having the filters on hand vs. driving to the big box store to get a couple is great. Box of filters arrives without damage and holds the filters next to the furnace for the year. By running the fan 24/7 air is continuously moved through the house and helps prevent cold and hot spots.

