HVAC Efficiency 101

When a young man considers the purchase of an engagement ring, he is told to remember the three Cs: clarity, cut, and carat. Real estate agents know that a homebuyer needs to know more about their purchase of a home than “location, location, location,” and helps them to explore the details involved in a real estate transaction. The same advice is commonly available to anyone purchasing an HVAC, but it takes a little research to get past the industry acronyms.

Everyone wants a good deal, but the total price of purchase is only a portion of the “bargain” equation. This is a large purchase: how can you know what you are buying? Do you just take the sales staff’s opinion?

Government agencies, trying to ensure the quality of HVAC products, require quality testing and publish the results of the tests on each component. However, to FULLY understand your purchase options, you would need to have a firm grasp of BTUs and kilowatt hours. Most people’s eyes glaze over before the explanation ends. So, government agencies do what they do best–they couch the results behind acronyms. But unless you educate yourself at least a little you will miss information that will help you make a better decision. Here is a quick guide on the most often-used acronyms associated with HVAC products.

EER and SEER Ratings

These acronyms are found on air conditioning products and represent Energy Efficiency Ratings or Seasonal Energy Efficiency Ratings. Simple enough to understand; but what does it mean? The tests measure the amount of electricity required to change the temperature in a defined space.

• EER is a measurement of electric energy needed to cool a given space under exact conditions—reducing the temperature from 95⁰ F to 80⁰ F with 50% relative humidity.
• SEER is more commonly published. It is an average of EER ratios under different temperature and humidity settings.
• A higher SEER number denotes better energy efficiency. In Texas, the minimum SEER for air conditioners in 2023 is 15, while higher efficiency units have a 26 SEER.
• What SEER cannot tell you is how well it will perform in your home. Other factors, such as insulation and the number of windows, also play a factor.

HSPF and AFUE

These acronyms demonstrate the energy efficiency of heating equipment for HVAC systems; one measures the energy efficiency of heat pumps and the other of gas and oil furnaces. The Heating Seasonal Performance Factor (HSPF) measures a heat pump’s efficiency and is very similar to the SEER number above.

• Your air conditioner uses heat pump technology, by moving heat from inside your house to the outside of your house. The same equipment is used during the heating season to move heat available outside to the inside of your home.
• HSPF is similar to the SEER number above since it is an average of the heat pump’s efficiency under a large range of temperature and humidity settings. The number reflects the amount of heat claimed from outdoors using a given amount of electrical energy (kWh).
• A higher HSPF number denotes better energy efficiency. Expect to see an HSPF number between 8 and 10; 13.5 is currently the most energy-efficient heat pump available.
• What HSPF cannot guarantee is how well it will perform in your home. Other factors, including insulation and weather stripping, also play a factor.

Fuel-powered furnace systems are also tested and have their own acronym—Annual Fuel Utilization Efficiency or AFUE. When fuel is burned, the system captures as much heat energy as it can; however, a portion of the heat energy escapes up the flue in the exhaust.

• AFUE numbers are simply a percentage of the energy captured by the system. A 78.0-rated furnace captures 78% of the heat energy available in the fuel but releases 22% into the atmosphere.
• As you would expect, the higher the number, the better the energy efficiency of the furnace. The most energy-efficient gas furnaces have a 98.5% rating.

Electric-powered forced air furnaces capture 100% of the heat energy available.

Hopefully, this information helps with your HVAC Efficiency purchasing decision. Keep in mind that higher energy HVAC Efficiency ratings generally cost more during the initial purchase but save money each month with lower utility bills.

Have Questions about HVAC Efficiency?

For more information about R.M. Mullinix and HVAC Efficiency, schedule an appointment, or visit our HVAC Maintenance information page.