Confused about Energy Efficiency Ratings? We can Help!

For anyone not directly involved in the HVAC industry, efficiency ratings can be a bewildering jumble of acronyms and numbers.

What efficiency ratings mean to you:

Efficiency ratings are determined in a laboratory where an exact set of indoor and outdoor conditions are specified by the US Department of Energy. Because each piece of equipment is evaluated using the exact same conditions, the rating can be used in comparing the performance of equipment from different air conditioning and heating manufacturers. The government uses the same test requirements for several types of energy ratings, such as AFUE, HSPF and SEER.

It is important to understand efficiency ratings especially when you are shopping for a new air conditioner, heat pump, or gas furnace. The more efficient the system, the lower your utility bills will be. All AFUE, HSPF and SEER ratings are derived from standard tests which are issued by the government and come from industry professional organizations.

Is buying more efficient HVAC equipment really worth the cost?

  • In many cases, yes. There are, however, a number of important factors that must be considered to answer this question. How much money you will actually save on utility bills depends on personal comfort preferences, utility rates (electricity, gas, etc.), and weather conditions – all of which can vary greatly.

  • Not to be overlooked is the aspect of quality. More efficient air conditioners and heat pumps are often built using higher quality materials and may have better warranties.

  • It is wise in all cases to consider the Total Cost of Ownership (TCO): Initial Cost + Cost to Operate ÷ Life Expectancy = TCO

We can help you sort through all the factors and custom design a system that’s right for you.

COMMON HVAC RATINGS:

SEER

The Seasonal Energy Efficiency Ratio is a measure of the cooling efficiency of your central air conditioner or heat pump.  It is the amount of cooling that an air conditioner (or heat pump) delivers per watt of electricity used.  The higher the SEER number the better the system is at converting electricity into cooling your home.  The industry minimum SEER is currently 14.00.

HSPF

The Heating Seasonal Performance Factor is a measure of the heating efficiency of a central heat pump. The higher the HSPF number the better the heat pump converts electricity to heat for heating your home. HSPF is a measure of a heat pump’s energy efficiency over one heating season. Heat pump industry minimum HSPF is currently 8.2.

AFUE

The Annual Fuel Utilization Efficiency tells how efficiently a gas or oil furnace converts fuel into heat. An AFUE of 80% means that 80% of the fuel is used to heat your home while 20% is wasted. AFUE is limited in that it only refers to the unit’s fuel usage and not its electrical consumption.  The industry minimum AFUE is currently 80%.

COP

The Coefficient Of Performance is a measure of heating capacity (in Btu/h) at standard heating conditions divided by its electrical input (in watts).  The higher the COP, the more efficient the unit is at converting electricity into heat.  This rating is commonly used for geothermal heat pumps where the source of heat (ground) is a stable temperature year round so does not require “seasonal” averaging like SEER or HSPF. The industry minimum COP for geothermal heat pumps is currently 3.6 on closed loop systems and 4.1 on open loop systems (water-to-air).

EER

The Energy Efficiency Ratio is a measure of cooling capacity (in Btu/h) divided by its electrical input (in watts). The higher the EER, the more efficient the unit is at converting electricity into cooling.  EER is not seasonally averaged (see SEER above).   The industry minimum EER for geothermal heat pumps is currently 17.1 on closed loop systems and 21.1 on open loop systems (water-to-air).

Anna Caddell