Attic Radiant Barrier Calculator
This entry was posted on June 22, 2014.
An attic radiant barrier is designed to reduce the amount of energy flow from the roof deck to the attic floor in the home attic environment, which thereby also reduces the temperature in the attic. Ideally, they're designed to reduce heat loss in the winter time and minimize heat gain in the summer time, which have a direct effect on heating and cooling costs.
The million-dollar question that most homeowners have when the topic comes up is, simply, do I need a radiant barrier? In other words, will a radiant barrier help with heating and cooling costs, which are seemingly always on the increase?
It's a tough question to answer without knowing more about your specific attic and city climate in order to get a good feel for whether or not it would be worth it to have one installed. But now, the Oak Ridge National Laboratory (the Tennessee Department of Energy lab that is also home to many of the world's most powerful supercomputers) has developed a tool to help you gauge whether or not a radiant barrier would make sense in your home.
Oak Ridge has put together a simple radiant barrier calculator and it only takes a few minutes for users to fill out their information to get a good read on things. Here is how it works:
- Step 1: Select a climate zone on the interactive map or choose from one of seven listed cities to decide on an area of the country that best reflects the type of climate you live in.
- Step 2: Enter the square footage of your attic floor size.
- Step 3: Select the type of attic insulation you have.
- Step 4: Detail the ductwork in the attic.
After you enter the information about your attic, all that's left to be done is click the "calculate" button on the bottom of the page. After the calculations have been made, you will be shown the approximate savings per square feet of attic, both with and without adding insulation (if applicable) as well as the approximate savings after one, six and 20 years.
Pretty simple, huh? It's a lot of good, thorough information that you can attain in just a few short steps.
It should not come as much of a surprise that the homes that yield the best savings are those that are southern located with unconditioned or conditioned HVAC installs, poor insulation and ducts in the attic. Here are the details for a hypothetical home in a Miami, FL-based climate, with a 2,000 square foot attic floor, less than R-30 insulation and ducts present in the attic:
- Savings of 9 cents per square foot with a radiant barrier.
- Savings of 11 cents per square foot with a radiant barrier and insulation.
That is a total of $180 and $220 per year, respectively - seemingly well worth the investment of installing a radiant barrier.
Conversely, a Minneapolis-based home, with quality attic insulation, a 2,000 square foot attic floor and no ducts in the attic would not yield any type of energy savings if a radiant barrier was added. Like we already noted, the homes that have the most to gain from adding a radiant barrier are those that are poorly insulated, have duct work and are also southern-based, where the weather plays more of a factor.
So next time you are staring down your utility bills wondering why they are so high and thinking of possible solutions, you can get a good read on a very practical solution just by heading on over to ORNL.gov to calculate your approximate energy savings in the radiant barrier calculator.