Everything You Need To Know About R-Value vs U-Value

Window shopping is more than just selecting a pretty window frame that fits the aesthetic of your house. Energy efficiency and insulation need to be taken into account as well, so you can stay comfortable and protected during the changing seasons!

You will often encounter various ratings and numbers when choosing a window, such as the R-value and U-value. There is a difference between these values, but both are related to measuring heat that passes through the window.

We’re pitting R-value vs V-value against each other in this ultimate guide.

What is R-Value?

The R-value measures a barrier’s thermal resistance and insulating properties. This value measures a window’s capacity to resist heat flow from one side to another.

When looking at the R-value of glass windows, ensure you aim for a high number between 0.9 and 3.0. The higher value means more excellent resistance to heat conduction that passes through the window.

What is U-Value?

On the other hand, U-value measures the rate of heat loss in your window. This unit also checks the performance of how well your U-value windows hold in heated or cooled air.

Have you ever encountered the term ‘U factor’? It means exactly the same thing as U-value. Either way, the numbers generally range from 0.1 to 1.0. So the next time you see one of these terms on a window, look for the lowest value as much as possible for little to no heat loss.

U-Value vs R-Value: Reading Energy Performance Labels

Buying replacement windows will expose you to various energy performance labels certified by the National Fenestration Rating Council (NFRC) or Energy Star. You’ll find the following values displayed:

• U-Factor;
• Solar Heat Gain Coefficient;
• Visible Transmittance; and
• Air Leakage.

Reading a window label will give you detailed information about a window’s energy efficiency. Simultaneously, the numbers you see for each rating serve as benchmarks for product comparison.

Energy performance rating labels typically don’t feature R-value ratings. Don’t worry if you don’t see it—it’s easy to compute its value. You only need to use this formula:

(R-value = 1/U-value)

For example, if a window’s U-value is 0.16, then R-value would be 6.25.

When it comes to R-value, remember that the ideal number should be higher since this means better resistance.

R-Value vs U-Value: Why Are They Important?

Just to recap, the U-value measures the heat escaping through the window, while R-value concerns heat resistance. If you think about it, they’re the inverse of each other!

Learning the U-value and R-value of a window will lead to the purchase of products with excellent energy efficiency. In fact, this eco-friendly decision could make you eligible for the Green Ontario Fund Rebate Program, which enables you to enjoy the following benefits:

1. Low Energy Consumption

A low U-value and a high R-value window increase your home’s energy efficiency. These qualities lessen heat loss and slow down heat flow through the barrier caused by the difference between indoor and outdoor temperatures. As a result, the energy used by your furnaces and air conditioning gets reduced dramatically.

2. Higher Cost Savings

Low energy consumption means higher cost savings! Investing in an energy-efficient window is one of the easiest ways to lower your utility bills.

3. Better Insulation

Choosing a window with a high R-value can keep you comfortable throughout the seasons. This kind of rating slows down the flow of heat, maintaining your indoor temperatures and keeping them unaffected by the outside climate.

Tips on Choosing the Right Windows for Your Home

Here are a couple of reminders to keep in mind when shopping for windows:

Don’t Settle for the First Window You See

Buying new windows is an investment—you wouldn’t want to experience regretting your window choices. Instead of settling for the first energy-efficient window you see, keep your options open. Keep “window shopping” until you find one with ratings that match your standards.

Consider Your House’s Architecture

Maximize your home’s natural light by learning about its architecture. Rooms that get direct sunlight should have windows with low U-value and high R-value ratings. This will prevent your room from overheating and maintain a comfortable temperature throughout the day.

Familiarize Yourself With Materials Used for Windows

Aside from window ratings, you need to be aware of how materials affect the performance of your windows. The most common materials used are vinyl, wood, aluminum, and fibreglass. Each has its own set of pros and cons; you must consider your needs and preferences to select the best window material.

Stay in the Loop with Ontario Window Reviews

Even though the U-value is more commonly seen on labels vs the R-value, they’re equally important when determining the energy-efficiency of a window. That’s why you should consider them both before you buy a new set of fixtures for your home.

Now that you know the basics of R-value vs U-value, it’s time to start shopping!

Ontario Window Reviews is a reliable portal that compiles reviews of the best window companies in Ontario. Through our site, you’ll learn about their offered services, customer ratings, and other key factors that can help you choose a a reliable window and door manufacturer.

Check out our comparison chart for more detailed information.