According to the U.S. Environmental Protection Agency (EPA), every dollar invested in HVAC energy efficiency can produce a double or triple return on investment. If your equipment is over 10 years old, upgrading to high efficiency equipment can pay for itself in a surprisingly short period of time. But, when looking to purchase or upgrade your equipment, what do HVAC energy acronyms actually mean?

Btu (British Thermal Unit): Most commonly used unit of measure for energy use in heating and cooling equipment: one Btu is the amount of heat required to raise one pound of water by one degree Fahrenheit. The higher the Btu rating, the greater the heating capacity of the system. 

SEER (Seasonal Energy Efficiency Ratio): Essentially, this measures your cooling equipment’s average efficiency over the course of a calendar year. A higher SEER rating equates to greater energy efficiency. Depending on what area of the country you’re in, your equipment should have a rating anywhere from 14-25. While a system with a higher SEER rating may have a higher initial cost, your annual energy savings will more than offset those higher upfront costs. 

EER (Energy Efficient Ratio): Like SEER, EER is also used to measure your system’s efficiency. The terms differ in that EER is calculated under specific test conditions that represent peak load during the highest temperatures of the season, while SEER is measured seasonally over the course of a year. In other words, if your office or business is located in an area with extreme temperature fluctuations, such as Arizona, EER might be a more relevant efficiency rating than SEER. For EER, look for a rating anywhere from 11.5-14.5

In either case, it’s important to look at both to get an accurate idea of the unit’s performance under different operating conditions.