Buying a new furnace isn’t as easy as buying something in a box and
plugging it in. Furnaces come in a variety of sizes and need to be chosen
carefully based on the square footage of your home. If the furnace is
too small, it won’t be powerful enough to warm your entire home,
which can lead to it running constantly and suffering wear and tear too
quickly. On the other hand, if the furnace is too large, it will run in
shorter cycles that also won’t provide even, adequate heating, plus
it will result in higher operating costs due to constantly turning on
and off. A professional HVAC technician uses a special formula to calculate
the size and AFUE needed for a particular space.