Garage Door Education: R-Value 101

Nov 15, 2022

Garage Doors

7 minute read

The garage is often the largest opening to a house, making it very vulnerable to extreme weather conditions. An insulated garage door can help reduce the transfer of heat or cold air into your garage and other areas of your home, thus improving your home’s overall energy efficiency.

When researching different types of garage doors, you may come across an “R-value” measurement associated with garage door insulation. This article will examine how to calculate the R-value of your garage door, and provide insight into the benefits of installing a new garage door with a higher rating.

The R-value of your garage door can help keep your home’s heating bills under control.
R-value of your garage door can help keep your home’s heating bills under control.

R-value explained

R-value is defined as the measure of thermal resistance to heat flow. A well manufactured insulated garage door consists of an exterior surface, an interior surface and an insulated core. The Door and Access Systems Manufacturers Association International (DASMA) lists a number of Technical Data Sheets (TDS) that provide more in-depth details around R-Value.  According to the DASMA information regarding R-value, your garage door can feature the insulating effect of air on a vertical surface, known as “air film.”  

Each of these elements has its own R-value that combines to create the overall garage door R-Value. The calculation is as follows:

R air films + R outside surface + R insulation + R inside surface = R section.

Also known as “Calculated Door Section,” the R-value assumes that air will be stagnant inside of a closed garage door and that the exterior of your home will have air moving against it.

R-value is an important consideration used throughout the construction industry. Many garage door manufacturers will highlight R-values to show the energy efficiency of their products. These calculations are based on the thickness of the insulation and its chemical properties. 

R-value calculations are based on the thermal conductivity of your garage door.

Foam Insulation has its own unique R-value, which is based exclusively on thermal conductivity (also known as a k-factor). As outlined by DASMA TDS #163, some garage doors will have varying thicknesses of insulation across their individual sections. If this is the case, an estimate of the total R-value is calculated by determining the thickness of the individual insulation sections and combining the results.

How R-value relates to your garage door

Now that you’re aware of how R-value is calculated, you may be under the assumption that a higher score indicates a garage door with better insulating properties. Although the materials within your door may individually have high insulation levels, this doesn’t mean that an R-16 value garage door is twice as effective as an R-8 rated alternative.

In this example, the higher-rated door doesn’t offer twice as much thermal resistance or twice the energy savings. A value of R-16 offers a 5% reduction in heat flow and a 5% improvement in energy efficiency over an R-8. 

This insulation r-value chart details the differences between the two, as well as other rating classifications.

This guide illustrates R-values and their associated energy efficiencies.
This guide illustrates R-values and their associated energy efficiencies.

The R-value of your garage door is typically rated between 0-20. Although a higher rating is possible, most residential doors fall somewhere in this range. A rating of 0 indicates that there is no efficiency for heat flow reduction at all.

If you tend to avoid going out to your garage in winter months — or you feel a chill in the air of your garage, even in warmer temperatures — chances are you’ve got a garage door with a low R-Value. Extreme temperature fluctuations shouldn’t occur within the interior of your garage. If you occasionally need an extra layer of clothing to take out the recycling, you may want to consider upgrading your garage door to an insulated unit with a higher R-value. 

The benefits of a higher rating go beyond personal comfort. Let’s examine how selecting a new garage door with a corresponding R-value can provide energy savings and home insulation improvements.

How will insulated garage doors help improve energy efficiency?

Whether you’re shopping for a new garage door or considering replacement of your existing door, a higher R-value equals greater overall value for your property. Wood or steel garage doors can contain the same R-value ratings, and any renovation project should factor in more than the aesthetic or curb appeal of your home. Here’s what you can expect to get out of your new garage door following a successful installation of your insulated garage door.

Temperature regulation

For attached garages, doors with an R-value of 10 or higher will help reduce the unwanted air transference that contributes to temperature fluctuations. If your garage is stuffy in the summer or freezing in the winter, injection foam insulation will help reduce air leakage and large heat variances. If you have an attached garage in your residence, the air in the garage can travel through the doorway to your living area. An insulated garage door will reduce the transfer of air from the outside to the interior of your home.

For detached garages with insulated garage doors, you’ll still want to select an R-value of at least 10 in order to properly protect stored items or vehicles. 

Lower energy costs

Poor quality garage doors, or doors with an R-value of less than 11, tend to lose heat faster than doors with higher ratings. If you find that you’re unable to keep your garage cool in the summer, for example, it is an indication that your energy efficiency is being affected dramatically by a lack of proper thermal insulation. Sourcing a new garage door or revitalizing your existing unit will improve the energy efficiency of your entire home and lower your annual utility expenses. 

Improved overall quality 

Regardless of whether your garage houses your vehicles or acts as a personal workout space, an insulated garage door can greatly affect the comfort level you enjoy while you’re in it. Homeowners who utilize the extra storage space or prefer to view their garage area as an extension of their living room all desire comfort when it comes time to step foot outside their homes. 

A garage is often the last barrier between the indoors and the world beyond: It’s also a shelter from the elements and can protect the quality of your vehicle as well as temperature-sensitive items that are typically stored within it, such as paint or fluid.

If you’re looking to maintain the quality of your stored items, select a door with an R-value of at least 10. Should you look to install a home gym or convert your garage space into a home office, an R-value of 16 or higher is recommended. Regardless of your selection, remember that proper care and maintenance of your garage door will contribute to its effectiveness. 

Amarr provides a complement of garage door designs with R-values to improve the energy efficiency of your home.

Amarr offers superior R-value garage doors

Amarr offers a variety of garage doors, each with a superior R-value that translates into energy savings for your home. Our Designer’s Choice line features triple-layer construction and insulation R-values of 13.35 or 19.40 depending on the unit.

Insulated Amarr garage doors feature polyurethane insulation, the industry-leading type of material that has a commonly rated R-value range of 12.0 – 18.0. Our insulation standards are in accordance with DASMA specifications and have received actual independent testing from their Commercial & Residential Garage Doors division.

When it comes to designing and installing an insulated garage door, we strongly recommend you source an experienced provider who understands garage door manufacturing.  

Having the right insulation product can make all the difference for your home’s thermal regulation capabilities. The choice between pre-expanded injection foam or rigid insulation materials can be difficult to make. Batt Insulation, for example, is commonly made of fiberglass and can reduce the R-value of your door if it becomes compressed or wet. Rigid foam insulation types such as the polyurethane material that new Amarr garage doors use aim to offer a consistent thickness throughout the sections of the door’s surface.

Amarr partners with a network of independent, professional garage door dealers who can walk you through this selection process to ensure you are getting the best insulated garage door to meet your needs.  

Find an Amarr Dealer near me to get started!