Central Florida Energy Consultant  

How Can an Energy Audit Help the Average Home Owner Save on Their Utility Bill?

How can the average home owner make a difference in their indoor air quality?

Q: What is a radiant barrier?

A: A radiant barrier is an energy saving product installed in the attics of homes and buildings that is excellent at reflecting heat and poor at absorbing heat. A good example of a radiant barrier is aluminum foil that is placed on top of a casserole to keep the top from burning. It works by reflecting the heat back into the oven. A properly installed radiant barrier does the same thing in your home, reflecting the sun's heat back out of the home, reducing the heat load on your home.

Q: How does it work?

A: Radiant heat is generated by many of the things around us. In summer, the sun is the primary source of radiant energy. It heats the exterior of your home, and this heat is radiated into the interior, primarily into the attic.

Q: Won't my home's insulation do the same thing?

A: No. While insulation is extremely important, it will not stop radiant heat transfer. In fact, a properly installed, radiant barrier actually increases the effectiveness of your insulation, in some cases by as much as R15.

Q: If I have a coat of radiant barrier on the underside of my roof, do I still need insulation and ventilation?

A: Yes. Radiant Barriers work in combination with effective insulation and proper ventilation to create the total Heat Defense System solution.

Attic Insulation

Q: What is the benefit of insulation?

A: Heating and cooling systems consume 50% to 70% of the energy used in the average American home. You'll save on your energy costs if you reduce the amount of energy needed for heating and cooling. Insulation helps your home retain heat in cold weather and reject heat in warm seasons.

Q: Doesn't my house already have insulation?

A: It may not have enough. In much of the housing in America, attic insulation levels are minimal at best. That's because many homebuilders only offer standard (minimum code compliant) levels of insulation in order to maintain competitive selling prices. Couple this with the fact that older insulation tends to settle over time, so if you live in an older home, you probably need to add insulation. But even in a newer home, additional insulation will save enough money in reduced utility bills to pay for itself, and those savings will, of course, continue. Upgraded insulation will also increase the value of your house.

Q: How does insulation work?

A: Heat flows naturally from a warmer to a cooler space. In cold weather, it flows from heated rooms to the unheated attic, garage or basement, or to the outdoors. In hot weather, heat flows from outside your home to its interior. To maintain comfort, the heat lost in winter must be replaced by your heating system, and the heat gained in summer must be removed by your air conditioner. Insulation resists the flow of heat, preventing unwanted circulation. The living space of a well-insulated house will stay warmer in winter and cooler in summer, with less energy costs.

Q: What is R-value?

A: The R-value rating refers to the insulation's thermal resistance - its ability to resist heat flow. The higher the R-value, the greater the insulating effectiveness. The R-value of thermal insulation depends on the specific type of insulation, its thickness and density. Installing more insulation in your home increases the total R-value and resistance to heat flow.

Q: What is the best kind of attic insulation?

A:  Blown fiberglass and cellulose attic insulation. Honestly both products are good insulators.

• Fiberglass is very light and tends not settle over time like cellulose might.
• Fiberglass has a R value or 3 per inch
• Cellulose is more dense than fiberglass and therefore is a better barrier for air movement through holes in walls and ceilings.
• Cellulose has a R value of 3.6 per inch   

Attic Ventilation

Q: Why ventilate the attic?

A: The primary reason to ventilate the attic is to remove the excessive heat that can build up due to the blazing Central Florida sun. With attic temperatures upwards of 160 degrees, an extremely hot attic puts a tremendous "heat load" on the living space coming from the ceiling area.  Attic ventilation is a cost effective method for removing this heat before it can penetrate your ceiling.

Q: What about adding more attic insulation rather than venting?

A: Insulation is a very important part of your home's defense against heat intruding into the living area. But in the case of an un-vented, super-heated attic, insulation cannot stop the heat from getting through. Remember that insulation is designed to RESIST heat transfer, not STOP it. The heat will eventually get through. The best solution is to have your insulation SLOW the transfer of heat long enough for your attic vents to remove it.

Q: What is the best way to vent my attic?

A: It depends. Be leery of any energy management contractor who uses only one type of attic venting system. Each home is unique. Ideally, solar powered vents are recommended for removing heat and moisture from the attic. Another method is to use an electrically powered attic vent.

Q: What are the Pros and Cons of each attic vent type?

Solar Attic Vent

Pro: Runs year round using no electricity. Very quiet yet moves a LOT of air, over 1275 CFM. No thermostat, i.e. does not require a "heat load" to start running. Comes on when the sun comes up.

Con: Does not work as well on the north side of home. This shortcoming can sometimes be overcome by putting the solar vent on a turbine base to elevate the vent.

Electrically Powered Attic Vent

Pro: The most powerful vent on the market, moving up to 1600 CFM. Can be installed anywhere. All steel construction. Virtually indestructible.

Con: Uses electricity to operate, which offsets some of the savings of attic venting.

Q: Wouldn't the most energy-efficient home be one that is the most airtight?

A: Controlled ventilation and air leakage are different matters. Sealing unwanted air leakage is vital to a home's energy efficiency. However, controlled ventilation in your attic is also very necessary.  Sealing off the attic space from the living space with expansive foam (see Building Envelope below) and/or an Attic Tent stair seal, then vents the attic area to remove the heat buildup.

Q: How does attic ventilation improve energy efficiency?

A: Ventilation promotes a cooler attic in the summer and a drier attic in the winter. By exhausting heated air from the attic, a good ventilation system will help keep the rest of the house cooler with less energy usage. In cold months, ventilation prevents moisture build-up in the attic. As warm, moist air rises into a cold attic, it can condense under the roof deck, causing the decking and shingles to distort and deteriorate. Excessive heat and excessive moisture can both lead to serious roof damage.

Q: Where does that moisture come from?

A: It comes from normal household activities, such as showers, laundering and cooking - activities that can release as much as two and a half gallons of water vapor a day. If this water vapor becomes trapped in the attic, it can cause roof decking and shingles to warp and distort. Lack of appropriate ventilation can void your home warranty or create a mold friendly environment.

Q: How does the vent system work?

A: As the sun comes up, the solar panel converts the suns light into "free" electricity, running the fan to remove the air as it BEGINS to warm up. As the sun increases in intensity, the fan reaches its maximum speed, increasing the air flow thus keeping the attic "heat bubble" from forming. As the sun sets, the fan speed decreases, thus not drawing moisture laden evening air into the attic. And because the vent uses a 20 watt solar panel, it even runs on cloudy days. The end result is that the attic is ventilated during the hottest part of the day, reducing the heat load on the home, making the home more comfortable and cost efficient to own. All without using ANY other power source than the sun to run the fan.

Q: What is the biggest advantage of this approach?

A: Instead of energy-consuming electrical fans, this system uses only the sun's energy to move air. It's highly efficient and costs nothing to run, paying for itself in as little as 5 years.

Building Envelope

Q: What do you do to stop air leakage from the home or in some cases into the home?

A: Durring a home energy audit or evaluation your home is assessed looking for indicators of air leakage. The most common culprits are as follows:

1. AC ducts and plenums - all duct joints should be properly sealed including the duct boots at the ceiling plane.

2. Attic Access Stairs - using an Attic Tent, we both insulate but also air seal the pull down stairs.

3. Recessed Light Fixtures - we install a duct board box over the recessed light and foam it to the sheetrock, eliminated air leakage while not affecting the performance of the light.

4. Exterior light and outlets - by installing air sealing gaskets behind all the covers.

5. Weather-stripping all doors and windows - using our proprietary weather-stripping.

6. Plumbing and Electrical Penetrations - using one part or two part polyurethane foam.

Savings - Return on Investment

Q: How much energy can I save?

A: The amount of energy saved depends on several factors, including your local climate; the size, shape, and construction of your house; the living habits of your family; the type and efficiency of the heating and cooling systems; and the fuel you use. According to a national survey of building improvements, you can save 10-20% on your heating bills just through improved insulation alone, so it's reasonable to expect even higher savings through the combination of insulation, ventilation and the addition of a radiant barrier.

Q: How soon will I see a return on my investment?

A: The average payback for installing energy saving systems in your home is 1 to 4 years depending on the type of systems and characteristics of your home.   As utility rates increase, the payback period will decrease, making these already attractive improvements in your home even more compelling.