The 411 on HVAC energy efficiency ratings and terms
(BPT) - Whether you’re looking to lower heating and cooling costs, or have a passion for protecting the environment, maximizing the energy efficiency of your heating, ventilation and air conditioning system is a smart move. The more energy efficient your system, the less you’ll spend running it every year, and the smaller your home’s environmental footprint will be.
Efficiency ratings are intended to help you decide which products are best for your home, so it’s important to understand what all the related terms mean.
Launched in 1992 by the U.S. Environmental Protection Agency, the ENERGY STAR program is a voluntary labeling system designed to help consumers identify energy-efficient products. ENERGY STAR rates products in more than 70 categories. Over the past 20 years, ENERGY STAR-rated products have helped consumers save $362 billion on energy bills and reduced greenhouse gas emissions by more than 2.4 billion metric tons.
Products that earn the ENERGY STAR rating are proven to operate using less energy.
Federal regulations require heating and cooling equipment to carry an EnergyGuide label that provides an estimate of how much energy the equipment will use. The label also compares the unit’s energy use to that of similar products, and gives an estimate of how much it will cost to operate the equipment in a year.
In addition to energy efficiency labeling, it’s important to know some measurement terms. Generally, for all these terms, a higher number equates to better efficiency.
SEER measures the energy efficiency of air conditioning systems and heat pumps. The ratio measures the amount of cooling provided by an air conditioner in comparison to the amount of energy the system uses — measured in watts per hour — over a hypothetical season. SEER can give you an idea of how energy efficient a unit will be under average conditions. However, a number of factors, such as how you use and maintain a unit, can influence energy efficiency, so it’s important to realize a unit might perform differently in your home.
EER is very similar to SEER, except instead of measuring efficiency over a season, EER tells you how efficient an air conditioning unit might be when operating at a typical temperature.
HSPF is meant to help you understand a heat pump’s energy efficiency over a season. It’s typically referenced alongside SEER to give a better picture of a system’s probable energy efficiency. The HSPF formula uses BTUs (British Thermal Units, a measurement of heat) to estimate the useful heat output divided by the total electricity (in watts per hour) the heat pump uses during a heating season.
One more energy measurement to know is the Annual Fuel Utilization Efficiency rating. The AFUE measures average efficiency for furnaces, boilers and water heaters. Like SEER and EER, the measurement is for a theoretical heating season.