What is the Importance of a Properly Sized Furnace System?


In today’s world, bigger is often considered better. That isn’t necessarily the case when it comes to heating and air conditioning systems. While you may be tempted to opt for the largest furnace if you can afford it, that’s not the wisest decision. Before purchasing a new furnace, your HVAC professional should properly size your home to determine the best units for your needs.

The Correct Way to Size a System

Correctly sizing a heating system means much more than simply determining the square footage of your home. As a responsible heating contractor, we use the Manual J “Residential Load Calculation,” published by the Air Conditioning Contractors of America (ACCA).

The calculation takes into consideration a number of different factors such as local climate, size, shape and orientation of your home, insulation, window area, location and type, air infiltration rates, number of occupants, along with the types and efficiencies of lighting and major home appliances. The most common mistake made is purchasing a furnace that is too big for your home.

Importance of Proper Sizing

Furnaces that are too small for your home will heat it too quickly, making it difficult to control the comfort level and also placing unnecessary stress on the unit. Systems that are too large for your home will short cycle, or turn on and off frequently.

Proper sizing will also include a Manual D calculation to determine the proper number, size and location of air ducts to ensure that the heated air is properly delivered. Manual D calculations are also important because they can point to a needed upgrade of your home’s ductwork if it is found lacking.

Benefits of Proper Sizing

Bellingham Proper Furnace SizeWith a properly sized furnace, you should not be able to hear the unit or the heated air running through the ducts. Neither should you experience any odors.

Expect comfort levels to remain consistent throughout the house with no rooms that are too drafty or too warm. If temperature changes from room to room, your system was not properly sized or balanced.

The most important benefit of a properly sized furnace is that it will run more efficiency, which can mean considerable savings in energy bills. Coupled with the overall higher efficiency in furnaces manufactured over the last decade, a new furnace will often pay for itself through energy savings over a handful of years of operation.

Are you looking for the right furnace size for your Bellingham home? Eagle Plumbing and Heating can help, just Call (360) 318-9999, to get reliable service from the professionals.