What are Window U-Values and how do they work?

Understanding the various ratings applied to windows and doors can leave a lot of homeowners confused. Generally, when a potential customer sees a high overall energy rating, they’ll believe that it means the window is great in every category.

However, a windows energy rating is comprised of several different measurements. Including the solar factor, air leakage and thermal transmittance. In this article, we’ll be taking a look at thermal transmittance, more commonly known as U-Value. Plus, the key information you need to know to keep your customer informed.

What is a U-Factor?

The U-Factor of a window (or thermal transmittance), is a measure of the rate at which heat transfers through the window itself. We measure this using three main factors, which we will later cover.

Generally, the lower the U-Value of a window the better. Low U-Values indicate that a window will perform well in maintaining the indoor temperature of a customer’s home. Recently building regulations have changed, meaning that new windows must have a u-Value below 1.6 W/m2k.

We’re proud to say that our liniar profile system achieves a u-Value of 0.9 W/m2k.

How do Window U-Value measurements differ from other surfaces?

For windows, there are some specifics that differ when making U-Value measurements compared to other surfaces, these include:

  • Ug Value = Which measures the thermal performance of the glass.
  • Uf Value = Indicates the thermal performance of the window frame.
  • PSIG = Which indicates the thermal performance of the frame spacers.

These factors combined give you the final U-Value of your window.

Are low U-Values always positive?

Whilst new buildings are required to have a u-Value of 1.6 W/m2k or lower, there are some cases in which a low U-value may not be ideal. This is generally only an issue in hotter climates, however, where warmer air needs to escape the home in order to prevent overheating.

The same could also be said for conservatories. If you were, for example, to have a conservatory without windows that open, the heat buildup in summer could become a problem. Therefore, we always recommend our clients select windows that provide them with greater flexibility throughout the seasons.

TruFrame windows provide a fantastic u-Value rating of 0.9 W/m2k, making our windows incredibly efficient. Partnering with a window supplier who is dedicated to providing not only stunningly beautiful and secure windows but also amazingly efficient, helps our clients win jobs. And impress when they do.

For more information about becoming a TruFrame installer, get in touch. Or follow our blog for the latest industry news.

18th November 2020

How To Use Social Media in a Double Glazing Business

In recent times, social media has become an integral part of our everyday lives, the same can be  said in business. Social media can be a valuable, cost-effective tool for businesses to market and promote their business to a wider audience, increasing their customer base and thus impacting sales.  The double glazing or fenestration industry […]

Read on

18th November 2020

How To Gather More Customer Reviews and Build a Reputation?

There are many factors that go into a customer’s decision when choosing a trusted window and door installer.  One of these factors is recommendations from others about your business.  What other people are saying about your business can have a drastic influence on a potential customers’ decision to hire you or not. Word of mouth […]

Read on

22nd October 2020

How To Generate Referrals From Existing Customers

As a business, you have most likely invested money into marketing your business and the services you provide, to attract new customers, and ultimately increase sales.  But marketing does always mean spending money directly on new customers. A bit of TLC to existing customers can pay dividends, not only in loyalty, but in generating referrals. […]

Read on