Does Radiant Barrier Work
Many customers do not know the importance of the correct levels of insulation thickness (R-Value) by the climate zone that they live in. This is crucial to lowering your energy bills as well as solves that hot room in the summer and cold room in the winter syndrome. Ventilation is also a key factor in the South, as the faster your remove the heat, the cooler the home becomes. Radiant Barrier is also a great means of lowering energy bills and in this blog, we will discuss all 3.
In South Texas we are in Zone 2 as shown by the Energy Star Map below. And the closer your home is to the water requires a higher R-Value. For most of The Texas Gulf Coast Area R38 and R-44 are sufficient for the humidity, as well as hot and cold temperatures. Energy Star recommends R38 for optimal energy savings for most of Zone 2. R-Value is a mathematical equation that simply determines a thickness of insulation to block the average temperatures of a certain region that takes in consideration the wall thickness with air gap. The thicker the insulation, the higher the R-Value but must have adequate space for that thickness. Compressing R-19 in a 2x4 wall is actually less effective than installing the proper thickness for that size wall as it reduces the air-gap which reduces the R-Value and efficiency.
For the Houston Area, the minimum recommended level is R-30 of 10.25-11 inches of insulation on the attic floor. Energy star recommends R-38 of 12.75-13 inches of insulation for maximum Energy savings and comfort. If you are within a few miles (5 miles) of the coast or a body of water, the minimum thickness recommendation is R-38 with an Energy Star recommended R-44 in the attic. In most cases the difference in cost between R-38 and R-44 is a few hundred dollars from a reputable company. We offer free evaluations of your insulation needs.
Ventilation is often overlooked by handyman services and inexperienced insulation companies as it is a bit more complicated to obtain the correct balance of air coming into the attic and venting out the top with the rise of heat. Many older homes have had ridge vents added while leaving the gable vents in place as well which causes many issues for a home. When adding a ridge vent the optimal vent to pull air in from is the roof eve vent as that causes the heat to rise from the bottom edge of the roof to the top. If the gable vents are still in place with a ridge vent, then the air below the gable vent does not rise out as quickly. So seal out the gable vent if you have a ridge vent and calculate the proper square feet of soffit eve vent for the size of the ridge vent. With a balanced ventilation system, the home will remove heat and humidity quickly. We offer free evaluations of your ventilation needs.
Radiant Barrier is a wonderful means of saving energy. However, there are good and bad products out there so read up on actual savings. Painted on radiant barrier, as well as radiant barrier roof decks, are the lower end in savings. On average a home owner will save between 5%-10% per year. Once the paint or deck gets hot, it has no means of heat removal so it radiates heat.
Single sheet foil barriers are better performing than the above and are installed to the roof rafters, which creates a chimney affect for your hot roof. This space in between forces the heat to exit the home. It must be installed correctly by leaving an air gap at the bottom and stop 8-10 inches from the ridge vent to allow the ridge to pull the air without creating a vacuum affect at the lower end by the outside walls. Average Real World Savings with Radiant Foil is 10-15% yearly.
Bubble Radiant barrier has an inherent R-Value as it has a built in air-gap in the materials so it performs much better than all of the above and in most cases is more expensive. The built in air gap slows the radiant transfer even further. For our area this is the best performing product. We use a double bubble material and our customers save an average of 30% yearly. Add R-38 upgrades to the insulation and you can expect to see an average of 35-45% per year with a properly ventilated attic.
There are other factors that help lower energy costs as these are just a few. We recommend having a proper Energy Audit and this in many cases can be free with your electric company. We offer a free energy audit of your insulation and ventilation needs with all of our estimates. A home properly insulated with radiant barrier and proper ventilation is more comfortable as well as more Energy efficient. With all insulation upgrades dont forget the Attic Tent as that seals out the home even further!