Whether you’ve been planning to replace your old AC or it breaks down unexpectedly, beginning your search for a new AC unit can be a bit overwhelming. There are several important factors to consider and a wide range to choose from. Understanding what you’re looking at when your HVAC contractor shows you different units can go a long way toward making the AC choice as easy as possible.
SEER ratings, or Seasonal Energy Efficiency Ratio ratings, are used to help potential buyers make a more informed choice of AC units for their homes. Much like a car’s miles per gallon, a SEER rating tells you how efficient the unit is while cooling your home. The higher the rating, the more efficient the unit.
Keep in mind that the SEER rating is not the same as how much the AC unit can cool. Instead, it tells you the AC’s efficiency when doing so.
The measure of how much an AC unit can cool your space is called the cooling capacity. Expressed in BTUh (British Thermal Units per hour) and often referred to as “tonnage,” this concrete measure represents the power of your AC unit. More specifically, it measures how much heat the air conditioner can remove from the air in one hour. Residential AC units range from 1.5- to 5-ton units, moving up in 0.5-ton increments.
Size and Other Variables
One of the most important factors in deciding the right AC unit for you is the size of the AC unit, which correlates to the size of your home as well as some other variables. While bigger is typically better — especially in Texas — AC units shouldn’t be too big or too small for your home. If the unit is too small, it won’t be able to keep you comfortable. If it’s too big, the strain on the system from short, frequent cycles will cause problems, such as early replacement down the line.
Have a professional conduct a load calculation to determine the proper AC size, or BTU requirement, of your home. In addition to square footage, variables factored into the calculation include:
- The number of residents
- Types and amount of heat-generating appliances
- Amount of direct sun exposure
- Number of windows
- Quality of insulation
- Regional climate
- Siding type
- Airflow quality
Once this load is calculated, you should stick to the given size range in order to receive the best results from your new AC unit.
As you head toward your next AC purchase, the most important thing to remember is that professional analysis is your biggest tool. If you find a trustworthy, experienced HVAC contractor to walk you through the buying process, it will be less stressful and more successful.