Radiant Barrier Insulation Benefits

This home improvement article on radiant barrier insulation looks at the benefits of installing a radiant heat barrier in your attic. We'll take a look at these benefits and see how they relate to different aspects of your home.

The first major long term benefit provided by installing radiant barrier insulation using materials such as radiant foil in your loft space is in the cost savings you will enjoy on your power bills. The savings aspect is often noted, but what exactly are the savings that are passed on to the homeowner when a radiant barrier installation option is considered?

Thermal Integrity Improvement

A study conducted by one authority on the subject, the Florida Solar Energy Center, concluded that correct installation of a radiant barrier is able to improve the thermal integrity of an attic space by providing an R value of 19. They reported a 16 percent reduction in energy consumption on a test site during peak demand during a summer cooling season.

This level of protection also significantly lowers the energy costs of a home over a typical heating season.

attic insulationThis level of insulation can be improved further with more energy savings by fitting additional insulation in conjunction with the radiant barrier. It has been confirmed by the Tennessee Valley Authority with studies that highlight the combination of a radiant barrier along with R-11 insulation turns out to be as efficient as R-19 insulation.

They have also confirmed that by combining a radiant barrier with an existing R-19 insulation package, you get the same benefit as a standalone R-30 installation. Savings of 10-30 percent can be made in a typical home protected by R-19 insulation combined with a radiant barrier system, although this depends on the placement being optimum for this kind of application.

Energy Saving

Efficient attic systems such as a radiant barrier is a great method for providing energy savings while improving the comfort level inside your home. Costs for installing will vary from manufacturer to manufacturer although average costs for both materials and installation labor is typically from 12 - 35 cents per square foot at the time of writing.

Costs are also dependent on location, so it is always best to consult several local companies for quotes. But when you consider the savings you will make each season on your energy bills for the life of the installation, which can be from 10-25 years, the initial cost is a sound investment for your future.

Radiant Barrier Installation

There are a number of ways that a radiant energy barrier can be installed in an existing home or a new build. It's worth knowing that all radiant barriers will have at least one surface that is of low emissivity (reflective).

This is in the form of a thin sheet or coating of aluminum. The sheet's emissivity is expressed by a value of between 0 and 1 and is arrived at by making a comparison with an opaque material that has no reflectivity.

With this type of insulating material, such as a foil barrier panel, there should be a value of approx 0.9, meaning that it has a reflectivity value of 90 percent. To function properly the reflective panel needs to face an open, unobstructed air space.

The best method of installation is in a brand new home build, although is not difficult to retrofit an existing home. The way in which this is done is by placing sheets of radiant barrier over the existing insulation that is installed in the attic space and is known as an attic floor installation.

The sheets are overlapped rather than being stapled in generally, to allow access to any wiring or plumbing pipes that may be underneath. The reflective side of the barrier must always be facing upwards and not touching the insulation to ensure the presence of dead air space.

This means that heat cannot be directly transferred from the insulation to the radiant barrier, preventing heat loss or gain in the home during winter or summer respectively.

A second method of installing a radiant energy barrier is by attaching the foil sheets closer to the roof itself. It is also possible to use insulating paint to increase the effectiveness.

This can be done in a new house build prior to the roof decking being installed by draping the foil sheets over the rafters, or attaching the radiant barrier directly to the base of the roof decking. To do this for a retro-fit, the foil sheets are attached to the underside of the roof's rafters, which allows for a minimum 3/4 inch gap of dead air space.

Ventillation is Important

An important consideration is to ensure that the attic is properly ventilated to prevent any water vapor forming beneath the radiant heat barrier which may condense and freeze in homes located in colder climates. To ensure there is proper air flow up in the attic space, new constructions often use a system of vented roof peaks and vented soffits to accomplish that.

In existing homes, installing an attic fan can help prevent this problem occurring. Certain radiant heat barrier manufacturers build a series of perforations into their panels to further ensure the air space breathes properly, while others have a substrate that allows water vapor to be naturally expelled without the need for holes being made in the foil panels.

Overall, fitting this type of roof insulation is a sound, long term economic decision as the homeowner the benefits of attic insulation from not only the cost savings on power bills, but also plays a part in helping the environment by reducing power consumption. This results in a double benefit where everyone wins.