By DON RACKLER, Jon Wayne Heating & Air Conditioning
SAN ANTONIO - Did you know that over half of all home cooling systems installed in the U.S. are the wrong size? If you have an older HVAC system, it was probably oversized in order to compensate for air leakage in your home.
Sizing HVAC systems is important because oversized HVAC equipment is not only more expensive to install, it also operates inefficiently, breaks down more often, and costs more to operate.
So, if you’re experiencing the symptoms of an improperly sized system, consider a replacement. Here are some things you should know about sizing HVAC systems:
1. Don’t go by the label - Some contractors use the label, or nameplate, when sizing a replacement HVAC system. The label on your HVAC equipment offers information such as the BTU per hour output, SEER ratings, etc. Using this information offers only part of the picture. Your contractor also needs to do calculations based on several factors in your home.
2. Manual J and Manual D calculations - The Air Conditioning Contractors of America (ACCA) has developed two methods for sizing HVAC systems. Manual J Load calculations determine heat loss from the building through walls and ceilings, leaky ductwork, and infiltration through windows, doors, and other access points, as well as heat gain due to sunlight, people, lights and appliances, doors, walls, and windows, and infiltration though walls.
Manual D is the standard method that contractors use to design residential HVAC duct systems.
Key factors for correctly sizing a cooling system include the following:
- Local climate
- Type and amount of insulation
- Windows- how many, where located
- Size, shape and orientation of the home
- Number and ages of occupants
- Air infiltration rate
Homeowners should insist that contractors use a correct sizing calculation before signing a contract. Since so many factors are involved, a thorough inspection of all above factors is necessary.
So, if you’re looking at a system replacement, remember—size matters! A properly sized system provides better home comfort, reduces your energy bills and breaks down less often.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about sizing your HVAC system and other HVAC topics, download our free Home Comfort Resource guide.
Jon Wayne Heating and Air Conditioning services San Antonio and the surrounding communities of Seguin, New Braunfels, Bulverde, Boerne, and Comal County. To get started, check out our current promotions...
Jon Wayne Heating & Air Conditioning
9272 US Highway 87 E
San Antonio, TX 78263