What are radiant barriers?
Radiant barriers are materials that are installed in buildings (can be in walls or roof) to reduce heat during summer time and to keep the heat loss in winter, and hence to reduce building or home heating and cooling energy usage and electric bills to keep the environment safe.
The potential benefit of attic radiant barriers or radiant barrier insulation is primarily in reducing air-conditioning cooling or warming loads in warm or hot climates respectively. Radiant barriers usually consist of a thin sheet or coating of a highly reflective material, normally aluminum, applied to one or both sides of a number of materials.
This material includes Kraft paper, plastic films, cardboard, plywood sheathing, and air infiltration barrier material depending on the construction.
Types of radiant barriers
A radiant barrier utilizes aluminum foils to reduce heat gains and losses during summer and winter respectively. They mainly are used under roof in the attic area.
Radiant barriers come in many forms and shapes for different applications:
- Single-sided foils backed by a supportive material like polypropylene or Kraft paper
- Foil-faced roof sheathings like foil-laminated OSB
- Double-sided foils with a strengthening material between the layers like polyethylene bubble-pack
- Foil-faced insulation (reflective insulation)
- Multi-layered foils; and radiant barrier chips
How to install a radiant barrier
Radiant barriers may be installed in attics in several different ways depending on the construction.
The simplest and easiest is to install the radiant barrier directly on top of existing attic insulation, with the reflective side facing up. The facing upside will reflect the heat waves coming from the roof top. This is normally called the attic floor application in builders’ terms.
Another way to install a radiant barrier is to attach it near the roof. The roof application has several different variations.
- hook the radiant barrier to the bottom surfaces of the attic truss chords or rafter framing
- drape the radiant barrier over the tops of the rafters before the roof deck is applied
- attach the radiant barrier directly to the underside of the roof deck in the attic.
Depending on the construction of the house, there can be several different ways to install radiant barrier insulation. Make sure to consult with an expert and chose the most cost effective way of installation.
How radiant barriers works
Radiant barriers perform a function that is similar to that of conventional roof insulation, in that they reduce the amount of heat that is transferred from the attic into the house through heat waves from the sun.
They vary in the way they lower the heat flow. Radiant barrier insulation reduces the amount of heat radiated across an airspace that is right next to the radiant barrier.
The primary function of conventional roof insulation is to trap still air within the insulation and hence reduce heat transfer by air movement in the attic area. The insulation fibers, chips or particles also partially block radiation heat transfer through the space occupied by the insulation.
Upwards of 90% of ceiling heat gain in summer months can be attributed to heat from the attic space above caused by radiant energy transferred by the sun. The radiant heat from the sun is engrossed by roofing shingles and transmitted it to the roof decking beneath and into the attic space. Conventional roof insulation absorbs much of this heat and six times its saturation point has been met, this heat is then transferred to the living spaces below through the ceiling.
When stapled to the bottom of roof rafters in an attic space, radiant barrier insulation can block 90% of the radiant heat from the roofing surface during summer time which in turn lowers overall attic temperatures by 35 degrees bringing the attic temperature closer to the true outdoor temperature or even lower.
By lowering the temperature in your attic, you can reduce the amount of heat transferred to your living spaces below by up to 45% giving you greater comfort in your home and reducing the load on your air conditioning unit. No matter what radiant barrier insulation you select, make sure to read radiant barrier insulation reviews before picking the right brand of the product.
The cost of a radiant barrier in Dallas/Fort Worth Texas
A radiant barrier costs within ranges of 10 cents to $25 per sq. ft for a single-sided barrier and $45 to $1 per sq. ft for double-sided ones. This, however, does not include labor costs for installation. Normally, the cost of installing a radiant barrier in Texas, USA ranges between 10 cents to $1 per sq. ft. The total cost may be around $300-$500 for a 1,500 sq. ft attic area. Most importantly, keep in mind that costs will always vary.