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Some of us only experience the summer heat for a few months out of the year, but others live in perpetually hot environments nearly year-long. If you are one such individual or simply want to ensure lower utility bills, choosing garage door insulation for hot environments may be the best option for you. Insulated garage doors are well-known for their energy efficiency and, thus, their ability to give homeowners a reprieve from higher-than-normal utility bills. However, they are a great option for those who want to use their garage as a secondary living space. Read on to discover the best garage door insulation for hot environments.

Things to Keep in Mind

Before choosing an insulation kit, you need to know what you’re buying and how it will help, if at all. A few facts about garage door insulation for hot environments need to be covered first. To do this, we need to take a brief look back at chemistry classes at school. 

Three Types of Heat Transfer

  • Conduction: When you think of conduction, think of when you turn on a stove to boil water. The heat transfers from the stovetop to the pot. Conduction is heat transfer from one stationary object to another through contact. 
  • Convection: This is the transfer of heat from a liquid, either in liquid or gas form, from one location to another. Also referred to as the spreading of heat.
  • Radiation: Heat from the sun is a good example of radiation, which is when heat is transferred through electromagnetic waves. 

U-Factor and R-Value

In order to determine what the best garage door insulation for hot environments is, two important measurements are used: the U-factor and the R-value. These measure the effectiveness of the insulation. 

  • U-factor: You may also see this referred to as a “U-value,” but these are interchangeable terms and mean the same thing. This measures the thermal efficiency of the garage door and heat transfer on a scale from 0 to 1. It operates purely in decimal form and on a reverse scale from the R-value. The lower the U-factor, the better the insulation will be. For example, a 0.5 U-factor is better than a 0.10 U-factor.
  • R-value: Whereas the U-factor measures the thermal efficiency of the garage door insulation, the R-value measures heat loss and efficiency of the insulation material, not the garage door itself. This is one of the most popular measurements used by manufacturers and operates on a scale of 0 to 16; the higher the number, the better. 

Garage Door Insulation Types

Garage door insulation kits come in many types, such as radiant barrier, fiberglass, cellulose, and foam. Each type has its benefits and downsides. Because the garage is one of the places in the home that could benefit most from better insulation, it’s a good idea to know the differences between each insulation type. 

Radiant Barrier

A radiant barrier is one of the best options for garage door insulation in hot environments. This material is made out of aluminum and is highly reflective. Better yet, it’s inexpensive. This insulation type is best for blocking heat instead of absorbing it. Typically, radiant barriers feature two layers with an air space in between. The air space layer reduces both conductive and convective heat flow. 


Unlike radiant barrier insulation, fiberglass absorbs the heat instead of blocking it. Fiberglass is most commonly used in insulating homes, making it a popular choice for garage door insulation. Fiberglass has a high R-value and low cost, making it a great option, but it is messy to work with. 


Cellulose is made from organic materials, such as plant fibers, cotton, and wood, which makes it an eco-friendly alternative. This does, however, make it the most expensive insulation material. Cellulose contains a fire-resistant borate treatment which is a huge plus to homeowners looking for a material to keep their home safe from fires. Like the other garage door insulation kit options, it does an excellent job retaining garage heat.


There are two types of foam insulation available, spray foam and rigid foam. 

  • Spray foam: This is the most inexpensive insulation available. As the name suggests, spray foam is a substance that can be sprayed onto a garage door to insulate. Unfortunately, it is not the most effective insulation material. 
  • Rigid foam: Also known as foam core, rigid foam is made from Styrofoam. It is lightweight, user-friendly, and affordable. There are three different types of rigid foam you will commonly find: expanded polystyrene (EPS), extruded polystyrene (XPS), and polyisocyanurate (polyiso). 

What is the Best Garage Door Insulation for Hot Environments?

If you live in a hot climate, the best insulation kit for you is a radiant barrier. As mentioned before, radiant barrier insulation is made of aluminum and reflects the sun’s rays. Bob Vila recently did a best-of buying guide of their top picks for garage door insulation kits. If you are in the market for garage door insulation for hot environments, look no further than the Best Garage Door Repair experts in Houston, TX. We can answer any questions you might have and install garage door insulation to keep your garage cool and your utility bills low. Contact us today.