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Kilowatt Heating, Air Conditioning and Electrical Blog

Why Air Conditioning System Sizing From Professionals Is Necessary


Years ago on our blog, we warned customers about the dangers of purchasing HVAC equipment online. There are plenty of reasons for this, such as getting a system with a voided warranty. A common item people purchase on their own is high-tech thermostats, thinking they can’t go wrong with basic climate controls. Unfortunately, a mismatched HVAC system and thermostat can end up damaging the HVAC system.

But the most important reason to never purchase HVAC equipment online is the issue of sizing. Unless you’re a professional HVAC technician, you won’t know how to properly size a new air conditioner to work correctly for your house. Sizing must be precise. A system that’s too large or too small means years of trouble from an AC that never seems to work right.

The Problems of Incorrect Sizing

The size of an air conditioner means how much cooling it provides a house, measured in how much heat it extracts. The term for an air conditioner’s cooling capacity is tons. One ton equals 12,000 BTUs of heat removed from 500 square ft. per hour. To give you a sense of average tonnage, commercial spaces need at least 25 tons of AC capacity, and may require over 50 tons. For homes, the number can range from 2 to 12 tons. And you can’t just guess based on the square footage of your house, since many other factors determine heat loss and heat gain.

The problems with an undersized air conditioner are obvious: the system will not be able to produce enough cooling for the desired comfort. The AC will run and run as it attempts to reach the setting on the thermostat, which it won’t be able to.

The oversized air conditioner presents a different problem—and unfortunately, people choosing to go with a bigger system “just in case” is a common trouble. The oversized AC will blast out cool air so rapidly that the thermostat will register it’s finished the job too early. It will then shut down the AC before its cooling cycle is done. The rapid start-and-stop will cause massive energy waste and wear the system down too early.

Professionals Can Do Sizing Right

You can find guidelines online about how to calculate the tonnage you need from an air conditioner. But any of these guidelines is a mere “guesstimate.” You are still at a high risk of purchasing an air conditioner that’s not sized right for your house, and it isn’t a mistake you can undo unless you replace the whole system.

Since you need to have professionals handle the installation of a new AC, have them on the job early to help choose the new unit. Experts will perform a complete load calculation on the house: this takes into account square footage, heat loss and heat gain from insulation and sun exposure, heat from appliances and lights, and the effect of the number of people in the home.

You can depend on our technicians for correct sizing and the finest air conditioning installation in Beverly Hills, CA, and throughout Los Angeles and the San Fernando Valley. We won’t take shortcuts: we’ll see you have the ideal AC.

Call our certified service technicians 24/7 for exceptional customer service! Kilowatt Heating, Air Conditioning and Electrical is here to help you survive summer in the coolest way.

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