## What is the difference between the SEER and EER rating of an air conditioner?

Friday, August 10, 2018

The Seasonal Energy Efficiency Ratio (SEER) is an evaluation of the energy usage over a typical cooling season, based on a constant indoor temperature of 80º F and varying outdoor temperature of between 65º and 104º F. It is a ratio of output cooling energy in BTU’s (British Thermal Units, a measure of heat production) to input electrical energy in watt-hours (one watt of electricity for duration of one hour). Because it is a ratio, there is no unit of measurement attached to it.

The difference between SEER and EER (Energy Efficiency Ratio) is that EER is an evaluation of the operating efficiency at the same indoor temperature setting of 80º F, but with a constant 95º F outdoor temperature.

The SEER rating is stated on the stickers on the outdoor (condenser) unit of an HVAC system, and a higher SEER means a more energy-saving system. Changing out a 15-year old system with at SEER of 10 to a new system with the current minimum SEER allowed by the U.S. Department of Energy of 14 would reduce your energy consumption by about 30% (the calculation is 1 minus 10/14).

Basically, SEER more accurately states the operating efficiency over  variable weather, while EER expresses the efficiency at one operating condition. Because EER is based on a more difficult scenario, it is a lower number and typically about 0.875 of SEER. So a heat pump or cooling air conditioner with a SEER of 15 would have an EER of around 13.

Also, see our blog post How can I find out the SEER of my air conditioner?

• • • • • • • • • • • • • • • • • • • • • • • • • • • •

How can I find out the SEER of my air conditioner?

My air conditioner won't turn on. What's wrong?

How can I find out the size of my air conditioner?

How can I tell whether the condenser (outdoor unit) is an air conditioner or heat pump?

Where is the air filter for my central air conditioner and furnace? I can’t find it?

Does an old air conditioner use more electricity as it ages?

What is wrong with an air conditioner when the air flow out of the vents is low?

Why has the thermostat screen gone blank?

Why does it take so long to cool a house when an air conditioner has been off for a while?

Why is my air conditioner not cooling enough?

What are the most common problems with wall/window air conditioners?

Visit our HEATING AND AIR CONDITIONING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.

How To Look At A House

site-built, mobile/manfuactured and modular homes

Search

This

Site

Attics

Air Conditioner & Furnace Age/Size

AFCI, CAFCI,

DFCI, & GFCI

Bathrooms

Aging in Place

Appliances

Click Below

to Collections

of Blog Posts

by Subject

Cracks

Doors and Windows

Electrical

Energy Efficiency

Fireplaces and Chimneys

Heating and Air Conditioning

Home Inspection

Hurricane Resistance

Electrical Receptacle Outlets

Electrical Panels

Garages and Carports

Common Problems

Exterior Walls & Structures

Insulation

Insurance

Life Expectancy

Mobile/Manufactured Homes

Older and

Historic Houses

Modular Homes

Metal Roofs

Plumbing

Pool and Spa

Roof and Attic

Remodeling

Safety

Site

Stairs

Termites, Wood Rot

& Pests

Structure and Rooms

Wells

Water Heaters

Water Heater Age

Septic Tank Systems

Plumbing Pipes

Sinkholes

When It First

Became Code

Park Model Homes

Shingle Roofs

Stucco

Wind Mitigation Form

"Does A Home

Inspector...?"

"What Is The Difference Between..."

Brick

Concrete and

Concrete Block

Foundations

Rain Gutters

Condominiums

Crawl Spaces

Building Permits

Clay Soil

Floors

Toilets

Generators

HUD-Code for

Mobile Homes

Flat (Low Slope) Roofs

Sprinkler Systems

4-Point Inspections

Building Codes

Inspector Licensing

& Standards

Washers and Dryers

Kitchens

Electrical Wiring

Plumbing Drains

and Traps

Smoke & CO Alarms

Top 5 results given instantly.

Click on magnifying glass

for all search results.

Lighting

Sinks

Electrical Switches

Siding

Water Intrusion

Electrical - Old

and Obsolete

Foundation Certifications

Tiny Houses