What Size Gas Forced Air Furnace Do I Need

Size matters the furnace s specifications.

What size gas forced air furnace do i need. If you get the sizing wrong you will have a hard time escaping winter s chill and or your energy bill. Note that the efficiency of your furnace will decrease with time and usage. An insufficient return system or one too large will reduce the efficiency of the heating and increase energy bills. You need to purchase the right size furnace to heat your home effectively and manage your energy costs.

Understanding furnace efficiency ratings. Some electric furnaces are 100 percent efficient. That means the furnace will produce 80 000 btu of heat. And if you re in need of a new furnace now is the time to act.

At 40 to 45 btus per square foot you d need a 100 000 to 112 500 btu furnace to heat your 2 500 square foot home. Leave it to our expert furnace size estimators. A mid sized home of 2 000 square feet would need approximately 50 000 to 60 000 btu to heat it properly. For example a furnace with an input btu can have an efficiency of 80.

But the average homeowner can t simply go out and buy just any furnace. Typical residential gas furnaces will be available in various sizes between 44 000 btu h and up to 120 000 btu h. If the furnace is putting out 1 000 cubic feet per minute of air flow the return system must collect 1 000 cubic feet and take it back to the unit. In the example above using an 80 efficient furnace the 2000 square foot home above would require a 100 000 btu input furnace which will produce the necessary 80 000 btu s output of heat.

If that same furnace has an efficiency of 95 the furnace will produce 95 000 btu of heat. Most furnaces are offered in 15 000 20 000 btu increments so you just need to get close in terms of sizing. With a less efficient furnace operating at 80 percent efficiency this would require a. The most common types are gas furnaces which are required to have at least a 78 percent efficiency rating with the most expensive models approaching 97 percent.

More than 500 specialists in residential heating and air conditioning told us about their experiences in installing and maintaining heating equipment.