air conditioner sizing

Before you start looking for the right air conditioner for your home, you need to have a load calculation done. Some contractors will simply ask you whether or not you were happy with the performance of your last air conditioner when determining the size of the new one. This could lead you to a decision that will cost you thousands of dollars.

A load calculation could be one of the most useful exercises you conduct to find out what the heating and cooling load is for your home. Making this calculation verifies that the new HVAC equipment will be the right size. If you do the calculation early enough in the selection process, you could also lower the conditioning load, which saves money on the equipment and your monthly utility bills.

A load calculation takes into account these factors about your home:

  • Its cubic footage
  • Insulation levels in the walls and attic
  • Windows, their placement and energy efficiency
  • Air infiltration rates
  • Preferred indoor temperatures
  • Appliances that create heat indoors
  • Age and number of home occupants
  • Landscaping factors

Going through the analysis with your contractor ahead of time tells you where the weak points of your home are, which you may be able to change to reduce the conditioning load. Adding insulation and sealing air leaks are two affordable and durable ways to cut the conditioning load.

Besides reducing the initial cost of the equipment and your ongoing conditioning expenses, the load calculation assures that the equipment you do select will be the right size for your home. Systems that are too large short-cycle, which means they turn on and off frequently. Short cycling increases your energy bills and the wear and tear on the equipment, prompting more frequent and serious repairs. An air conditioner that’s too large won’t remove as much humidity, and a heating system that’s too small won’t heat your home adequately during our coldest weather.

After you’ve finalized the size of the new HVAC system, the next step is determining the ductwork design, which is as important as the equipment itself. A ductwork system that’s been properly sized helps reduce the noise associated for forced-air HVAC equipment and ensure that all rooms in your home are comfortable.

If you need to have a load calculation performed, have a Reliance Home Comfort Advisor do it for you. Click here for details.

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