In addition to consuming excess energy, oversized air conditioners do a poor job of providing indoor comfort. These units cycle on and off rapidly throughout the day. This phenomenon, called short cycling, interferes with proper function of the evaporator coil. Humidity is not adequately extracted from the air. In addition, room temperatures tend to be inconsistent and continuously in flux. The repeated on/off action also increases wear and tear and leads to early failure of expensive components like the compressor.
Undersized equipment does not produce adequate cooling or heating. These units will remain in the “on” cycle for extended periods of time just to reach thermostat settings. This wastes energy, contributes to excessive greenhouse gas emissions and reduces the expected service life of the unit.
Accurate HVAC sizing requires the use of Manual J, the industry standard software for load calculations. As part of the sizing procedure, the contractor inputs room-by-room data specific to the home, including its orientation to the sun, square footage, number of windows and type of glass, airtightness of the structure, amount and type of insulation and ductwork condition. The software converts the data into a load calculation that can be matched to the specifications of an A/C or furnace that accommodates the home’s requirements efficiently and in the most environmentally-sound manner.
For added efficiency, choose Energy Star-qualified equipment. Rebates and federal tax credits can make this investment easier for many homeowners. Check the Energy Star website to see what equipment is eligible for rebates in your area.
For more information about proper HVAC sizing for your home renovation, contact the professionals at Sage Builders LLC in Newton.