Questions to Ask before Installing an Air-Conditioning System

Questions to Ask before Installing an Air-Conditioning System

Posted by
Ed Miller on Thu, Aug 11, 2011

It’s hard fact of life – air conditioners do not last forever. The upside? Replacing your old system with a new one will save you more money that you thought. Efficiency has improved a lot since that old hunk of metal and noise was first installed in your back yard.

The right air conditioning system is wholly dependent on your family’s needs. Here are three essential questions you should ask your contractor prior to installation:

1. How will the new air conditioner be sized?

The proper way to size heating and cooling systems is to calculate the actual heating and cooling loads for your home. To do so, the contractor has to measure the house completely, get all the insulation R-values, window types, orientation, infiltration rate, duct leakage, and more. Then they put all that into their load calculation software and find out how many BTUs per hour your home needs.

Proper sizing is important because an air conditioner does two jobs: cools the air and dehumidifies the air. In a humid climate, an oversized air conditioner will cool fine but won’t dehumidify well. Also, oversized systems go on and off a lot, and all those start-ups and shut-downs will shorten the life of your air conditioner.

2. Does the contractor test for duct leakage?

It requires a lot of functions and process to make your home cool and comfortable. One of the biggest features is the distribution system. If you’re paying a lot of money each month to run your air conditioner, you don’t want to waste that cooling through a lot of leaks in your ducts.  A duct leakage test will determine how bad your ducts are.

3. Does the contractor assess the air flow in the duct system and make recommendations for repairs?

Duct leakage isn’t the only problem with getting cool air into your home. Many duct systems don’t move as much air as they should because of ducts that are too small, kinked, too long, or have other types of constrictions. At a minimum, your HVAC contractor should measure the total external static pressure and make sure it’s within the limits specified for the equipment they’re installing. Ideally, they’ll also measure the air flow to each room to make sure your home will be heated and cooled.




Air Conditioning,



Air Conditioning Ducts

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