Following are the best air filters 1) AIRx Health 1" MERV 13 Furnace Filters. 2) Honeywell FC100A1037 Ultra Efficiency 4" Furnace Filters. 3) Nordic Pure 4" Furnace Filters. 4) FilterBuy 1" Furnace Filters. 5) AIRx ALLERGY 1" Furnace Filters. 6) Filtrete Micro Allergen 4" Furnace Filters. 7) X6673 Lennox 4" Furnace Filters.

It's basic function is to clean the air that circulates through your heating and cooling system. Filters trap and hold many types of particulates and contaminants that could affect your health and comfort, including: Dust and dirt.

When choosing heating fuels or systems, consumers may want to compare the cost of different heating fuels or energy sources. Because heating fuels are measured and sold in different units, such as gallons of oil and propane, cubic feet or therms of natural gas, or kilowatthours (kWh) of electricity, comparing the price of fuels in dissimilar units