Why Are Heat Loss and Heat Gain Calculations Important For Homeowners?

As we explained above, oversized central furnaces and central air conditioners almost always result in less efficient heating and cooling. This sizing problem, of course, also leads to higher energy bills every month. Instead of blindly trusting an HVAC technician's recommendations, homeowners can utilize heat loss and heat gain calculations to appropriately size the most efficient heating or cooling unit for their home.

Is It Worth Discussing Heat Loss and Heat Gain Calculations With Your Contractor?

The National Renewable Energy Laboratory (NREL) finds that oversized HVAC equipment is responsible for higher energy use rates due to increased on/off cycling and parasitic off-cycle power. Essentially, the extra power of larger central air conditioners and furnaces will more quickly get your home to its desired interior temperature, thus causing it to cycle on and off more frequently. This cycling requires extra energy usage and can also negatively affect the lifespan of your HVAC equipment. As a useful comparison, the short bursts of energy that happen with oversized HVAC equipment can be likened to the worsened gas mileage drivers get when driving through stop-and-go traffic during rush hour. Though your contractor may charge extra money for a detailed heat loss and heat gain calculation, this should ensure that you properly size the HVAC equipment for your home renovation. This step usually results in lower upfront costs as smaller equipment is generally cheaper. It will also save you money in the long run through increased operational efficiency. Finally, an oversized system will result in reduced comfort. An oversized air-based system will result in uneven temperatures throughout the home unless the fan is set to run independently of the need to heat and cool. An oversized air conditioner won't be able to remove as much humidity that is responsible for much of our summertime discomfort.

Are Heat Loss and Heat Gain Calculations Useful For Various House Certifications?

Heat loss and heat gain certifications are usually part of a more comprehensive energy performance certificate required by LEED and other sustainable home certifications. These certification programs can help homeowners apply for national and local tax rebates and other necessary zoning allowances. The couple hundred extra dollars you pay for an in-depth heat loss or heat gain calculation should be able to pay for itself down the road.