Furnace filter recommendation?
In the U.S. they are in green packages at the HD. After dealing with the performance of the restrictive performance of the 3M Filtrate, I switched a few years ago to the Merv 8 filters to avoid choking the system.
I have a slight allergy to cats, medium to ragweed/goldenrod and severe to horses. Fortunately, no horses in the house and my 2 large, black cats never bother me and my filters are quite clear when I change them every month or two. I run the fan 24 hours for 5 months when heating/circulating and on automatic when cooling.