ThermaDoor™ > Garage Door Insulation

Garage Door Insulation

Why should you insulate your garage?

Your garage can allow up to 25% of all sources of heat and cold into your home daily. Not only are you losing money, you're also losing comfort. Insulating your garage door with ThermaDoor Garage Door Insulation can help you save money on your energy bills, make your home more comfortable and help you get more use from your garage, year round.

Why should you use ThermaDoor Garage Door Insulation?

ThermaDoor Garage Door Insulation is a construction grade EPS (Expanded Polystyrene) insulation panel, laminated with an impact resilient, easy to clean, Vinyl finish. ThermaDoor Garage Door insulation has been specifically designed to fit to the internal panel of most sectional garage doors.

Insulating your garage door with ThermaDoor Garage Door Insulation can help you save money on your energy bills, make your home more comfortable and help you get more use from your garage, year round.

ThermaDoor Insulation Panels have acoustic qualities that help provide a sound insulating barrier, and has an R Value of 1.47 that contributes to your homes energy efficiency.

Understanding Insulation

The level of living comfort is determined by the quantity of heat that must be added to, or removed from a building; and Insulation is designed to control this factor.

Heat always flows from warmer to colder areas i.e. from a heated building interior towards colder air outside or from hot outside air to cooler interiors. This movement or transfer of heat occurs by one or any combination of the following methods:


Heat energy is transferred directly through a material, or between two materials, in contact with each other, where a temperature difference exists. Heat transfer along a metal rod is a simple example of conduction such as the heat conducted along a teaspoon in a hot  drink.


Air when heated, becomes less dense than the surrounding air, and rises upwards. The denser and cooler air flows downwards. When these air movements (convection currents) occur in spaces between the framing members of ceilings or walls, a significant amount of heat may be lost (winter) or gained (summer) reducing energy efficiency.


Heat energy may be radiated across an air space and then be absorbed by another body. Radiant energy from the sun is an example where this energy may be absorbed as heat or reflected by roofs and walls even on cool days. Consider the options for controlling horizontal heat flow across a 50mm vertical air space in a wall. This chart shows the reduction of horizontal heat flow in a typical 50mm wall space.

Understanding Insulation Graph

What is (EPS) expanded polystyrene system

It is a lightweight cellular material consisting of fine spherical shaped particles which are comprised of 98% air and 2% polystyrene. This air is trapped within a number of closed hollow cells in each particle.

Thermal Conductivity of EPS

The low thermal conductivity of EPS is a result of the combination of

The smallest contribution to thermal conductivity of EPS is the Polystyrene itself, and this contribution is in the order of 10% of the total.

Air that is not moving is an excellent insulating material. Because of this, the permanently entrapped air within the cells of EPS ensures its very low conductivity.

It is this factor which gives EPS its outstanding thermal insulation properties.

How EPS Insulates

How EPS Insulates

Heat is slowed dramatically passing through EPS by trapped air. Temperatures are more easily controlled as heat does not readily escape or enter through the panel. This makes it ideal for Garage door Insulation.

Heat Flow Terms and Comparisons

Within a material or between materials in close proximity heat will flow from a higher temperature to a lower temperature through one, or any combination of all three heat transfer methods conduction, convection and radiation.

The rate at which heat will flow through a material or between materials is dependent not only on the nature of the materials, but also upon the difference in temperature between the hot and cold sides.

Comparison of the effectiveness of insulation must be made on a basis, which excludes the influence of variable factors such as thickness and temperature differences. This comparison of thermal conductivity can be measured by the Thermal Conductivity ('k' value).

Thermal Resistance – R Value (m2K/W)

The R value, or thermal resistance of a material, expresses the ability of a particular thickness of that material to resist heat flow i.e. R = thickness of material/k value. It is the inverse of Thermal Conductance.

The R value is a measure of the ability of a particular material to resist heat flow.

EPS and the environment

Where EPS is used to insulate buildings it has a negative carbon footprint, saving far more in CO2 emissions than it emits during manufacture and disposal.

EPS insulation panels cut building CO2 emissions by up to 50%. The energy used to produce EPS is recovered in less than six months. As the insulation performance of EPS does not deteriorate it continues to reduce the energy requirement, fossil fuel dependence and energy related emissions of a building over its full lifespan. The performance characteristics of EPS do not deteriorate over time. EPS panels have been removed from buildings after 30 years with no noticeable change in insulation performance or appearance.

EPS is highly energy efficient. The energy saved over the lifetime of EPS insulation panel in reduced heating demand, more than comprises for the raw material used in its production.

The effective applications of EPS insulation can cut carbon dioxide emissions by up to 50%. The energy used in its manufacture is recovered within 6 months by the energy saved in the building when EPS is used to insulate buildings.

EPS do not contain ozone depleting substances in manufacture and composition. EPS is made without CFC's, HCFC's or HFC's. Manufacturing is done with blowing agents that have Zero Ozone Depleting Potential (ODP).

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By simply adding ThermaDoor Garage Door Insulation to your garage door, you will increase the thermal comfort of your garage, reduce your energy bills, and provide an additional barrier against noise, creating a TRUE and COST EFFECTIVE extension of your home.