Installing a new HVAC system is one of the more significant expenses you’ll face as a homeowner. Given the sheer cost, it’s tempting to only look at the price and choose your system based on what seems reasonable to you. However, this often leaves you with an improperly sized system, which won’t serve your home effectively. Discover what HVAC size means, why it’s important, and how to determine the proper size units for your home.

Understanding Sizing

HVAC sizing refers to the capacity for either generating heat for or transferring heat from your home. HVAC units use British Thermal Units, also referred to as BTU, to signify their size. A single BTU is the amount of heat needed to raise one pound of water by one degree Fahrenheit.

You’re not trying to heat water in your home’s air, so how does BTU translate into heating or cooling? The BTU is simply a measure of heat and heat transfer. Scientists and engineers have studied how much BTU is needed to heat or cool homes for over 120 years.

Generally speaking, the higher the BTU rating on an HVAC system, the more heat it generates or transfers. While it may seem that getting more capacity would more effectively control the temperature in your home, this is not necessarily the case. Let’s unpack why.

Why Getting The Right Size Is Important

Let’s explore why getting the right size HVAC system for your home is critically important. The short answer is that getting the right size system ensures that it will effectively heat or cool your home.

When you choose a system that’s too small because you focused on a price instead of need, you’ll increase your operating costs. Your system will end up running longer heating and cooling cycles, consuming more energy. The longer cycles also mean increasing the wear on your system, leading to more repairs and shorter service life.

Conversely, as mentioned previously, an oversized system with too much capacity is just as problematic. These units end up tripping sensors designed to protect the system from damage. This causes the system to turn off before it has completed a reasonable cycle. This process is called short cycling and leads to more starts of the system, which is the most wearing part of the cycle and consumes the most energy. Therefore, when your system short cycles you never get to your ideal temperature, but you experience higher utility bills, more repairs, and shorter service life.

There Is No One Size Fits All Answer

When it comes to sizing the unit for your home, there is no one-size-fits-all answer that works for every home. Each home is unique in its heating and cooling needs, even if they are the same size.

When working with a company to get new HVAC units, it’s important to find a company that understands proper size calculations. This should go beyond simply your home’s size in square feet. This is one factor that separates HVAC professionals from simple hobbyists or the generic “handyman.”

Factors in Determining the Right Size

You can see why installing the right size system is so important and how it will save you money in the long run. To get the appropriately sized system, HVAC technicians use an algorithm known as the Manual J calculation. This starts with the serviceable area, which isn’t just the square footage of your home. Rather, it starts with the cubic feet of serviceable area, so your ceiling height is a factor.

Then it looks at how your home either generates or transfers heat on a normal basis. This takes into account your windows, doors and insulation. It also considers how much shade your home receives and how your home sits compared to the path of the sun throughout the day. It also considers heat-generating appliances in your home, including not only your kitchen but things like high-power computing equipment. Finally, it considers how many people occupy your home and how you use the space in it. All of this helps a technician recommend both size and type of HVAC system to meet your particular need.

People around Lake Elsinore have trusted Polar Express Heating & Air Conditioning to provide trusted HVAC service since 2014. Our team provides heating and air conditioning installation, maintenance and repair combined with air purification, filtration, and humidity control solutions. Call to schedule your consultation with one of our HVAC installation experts to find the right size system for your home today.

Meet the Author
Anthony Dieringer
Anthony Dieringer

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