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What Size AC Does My House Need?



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A home’s air conditioning system needs to be sized properly in order for it to cool the home properly and operate as efficiently as possible. The problem is, there are several factors that can impact the size of a central air conditioning system. This is why it is so important to trust a professional with this task. But, if you want to learn what goes into this delicate process, the following information will help you learn how to size your air conditioning Wilmington NC.

What Sizes of AC are Available?air conditioning repair wilmington nc

Many homeowners think that central air conditioning systems are custom-made for each home and this is not usually the case. Central air conditioners are measured in what is known as “tons.” It is important to recognize that in relation to AC systems, “tons” does not reflect the weight of the system. Instead, it is the figure that is used to measure an air conditioner’s ability to cool. In this case, one ton is equivalent to 12,000 BTUs (British Thermal Units).

A BTU is the amount of energy that’s required to heat or cool one pound of water by one degree Fahrenheit.

So, when an air conditioner is labeled as a one ton AC system, it is capable of cooling 12,000 BTUs (or cooling 12,000 pounds of water by one degree) in an hour. If the system is a two ton system, then it can cool 24,000 BTUs (or 24,000 pounds of water by one degree) per hour.

Residential air conditioners typically range in size from one to five tons with increases occurring in half-ton increments. Anything over five tons is generally considered a commercial HVAC system and if a home is large enough to require a commercial system, then in most cases, a zoned system will be installed consisting of two or more smaller systems.

Why is Sizing Important?

Some homeowners think that if a home is designed for a three ton air conditioner, then upgrading to a four ton system will provide more effective cooling. But, this is actually incorrect. A modern HVAC system is designed to operate in a cycled fashion, meaning the system turns on, runs for a short period, and then turns off. This enables the system to cool the home gradually and keep the interior temperature consistent.

If a system that’s too large for the home is installed, then the system will turn on, cool the home very quickly, and then turn off. The on and off cycle will be much lengthier, allowing heat to build up in the home until the system kicks back on again. This makes for a very inefficient way to cool a home and with energy costs as high as they are, energy efficiency needs to be the primary concern.

On the other hand, if a smaller-than-recommended system is installed, then it will run constantly because it simply won’t be able to maintain the temperature you want your home to be for very long. And, since the system will run and run, your energy bills will climb and climb.

Air Conditioning Sizing Equation

The standard equation used to estimate a home’s air conditioner size is as follows:

Required tons = the square footage of the home multiplied by 25 with the answer divided by 12,000 and that answer subtracted by 0.5.

Here’s an example for a 2,000 square foot home:

  1. 2,000 x 25 = 50,000
  2. 50,000 / 12,000 = 4.16
  3. 4.2 – 0.5 = 3.7

So, in this case, the home can accommodate either a 3.5 or 4 ton system.

Get Air Conditioning Repair  Wilmington NC – Call Tidewater Today

In order for your home to be as comfortable and energy efficient as possible, it needs to have the right sized air conditioner installed. The above information is just a guideline. In order to ensure your system is properly sized, you need to hire a professional AC installer because there are still other factors that can affect the sizing of your system, such as the type of insulation your home has, the height of the ceilings, and more. For the best results, trust Tidewater Heating and Cooling.

Tidewater Heating and Air Conditioning is fully licensed and insured and we’re committed to your satisfaction and comfort. Just call us today at 910-499-4755 for prompt air conditioning repair Wilmington NC service and professional installation.