Understanding What Energy Efficient Window Labels Mean

4.8

Rating by 7,250+ Customers

(opens in a new tab)


Energy efficient windows are a great addition to your home that can make you more comfortable and keep your heating bills down.

Once you decide to replace your home’s windows, you’ll have plenty of brands and models to choose from. This can be a bit overwhelming if you don’t know which type of windows are right for your home.

Energy efficient windows come with labels, but the average person isn’t likely to understand what they say. Knowing what those labels mean can help you compare windows and choose which features are right for you. You’ll be able to make an informed decision rather than just choosing windows at random or relying on somebody else’s advice.

  • Manufacturer’s Label
    This will include the name of the manufacturer and the model number. It will also provide more information including the frame materials used, the number of panes, the type of gas that fills the gap in multi-pane windows, the glazing style, and Low-E information.
  • NFRC Label
    You should see four or five numbers in a large bold font. These are from an independent organization that tests and certifies the windows. The following numbers will be listed on the NFRC label:

    • U-Factor
      Measures the effectiveness of the windows keeping heat inside your home. Lower numbers mean more energy efficiency during the heating season.
    • Solar Heat Gain Coefficient
      Measures the effectiveness of the windows blocking unwanted heat from the outside. Lower numbers mean more energy efficiency during the cooling season.
    • Visible Transmittance
      Measures the amount of light a window lets in. Higher numbers let more light in which can save you on artificial lighting.
    • Air Leakage
      Measures how much air a window lets in. Lower numbers mean tighter air seals.
    • Condensation Rating
      Measures how well a window can resist condensation. Higher numbers mean more resistance.
  • Energy Star Label
    This label will feature a logo if the window meets guidelines for your geographic area.

To find out more ways to keep your home warm, contact Wolfers Heating at 503-220-1901.

Recent Posts

Beginning work on a furnace

Don’t Wait for Winter: Signs Your Older Portland Furnace Needs Repair or Replacement This Fall

An air conditioner being worked on outside a home

Is Your AC Running Non-Stop But Your Portland Home Stays Warm? Here’s Why

White wall-mounted split AC unit with the front panel open and dark vent louvers visible inside the grill.

Can I Add Air Conditioning to an Older Portland Home Without Ductwork?

Contact Us

Name(Required)
I'd like to receive SMS messages about Wolfer’s Home Services.
By submitting this form, you authorize Wolfer’s Home Services to contact you regarding your inquiry, appointments, or services requested. Messaging frequency varies. You can opt out at any time by replying STOP. Reply HELP for assistance. Message and data rates may apply. We will never share your personal information with third parties for marketing purposes. You can opt out at any time. Consent is not a condition of purchase. | Terms & Conditions | Privacy Policy

Unbeatable Heating, Air Conditioning, Plumbing & Electrical Services

From everyday repairs to major home comfort upgrades, Wolfer’s Home Services is ready to help. Our experienced technicians provide dependable HVAC, plumbing, and electrical solutions backed by more than 125 years of service and our commitment to five-star customer care.