As the summer heat increases, cranking up the air conditioning to keep temperatures down only makes your brain boil when the electricity bill comes in the mail. Those extra clicks on your thermostat also are leaving a much heavier carbon footprint.
Global Green, a nonprofit agency helping create sustainable buildings and cities, offers tips and resources to homeowners and builders to keep home energy costs down through its Build It Back Green (BIBG) program.
BIBG's energy efficiency fellow Myron Warden offers these suggestions to keep your house cool while reducing energy consumption — and sticker shock from your electricity bill.
Seal it up. Sealing attic floors and doors and windows is a year-round must. Warden says the biggest challenge is for older homes built before HVACs became the norm — and before air sealing and insulating and weather-resistant barrier systems were taken seriously, leaving homes to leak cold air through windows and doors, and through wire, plumbing and other holes in the wall. Look for environment-friendly and formaldehyde-free caulk.
Create a breeze. Use ceiling fans, but without an air-sealed room, they'll just be pulling air from outside — "hot-humid NOLA with 'air you wear,'" Warden says.
"It's all about ventilation, not infiltration," he says. "Infiltration is air moving through cracks and openings through pressure differences. Ventilation is controlled movement of air, i.e. a well-sealed forced-air system that brings [in] fresh air from outside. It's important to know where the air you're breathing is coming from."
Also be sure bath and kitchen exhaust fans are blowing air to the home's exterior — air being pushed into the attic will rain through the cracks and openings on its floor.
Insulate. While air sealing resists air, insulation resists heat. Target attic floors first, then underneath the home, then the walls. "Air sealing the exterior and interior walls, as well as air sealing the attic floor and air sealing the cavities underneath the house is more cost effective than drilling holes along the exterior walls and filling them up with insulation," Warden says. "Always remember that in this hot, humid climate, moisture will get in the wall cavity and it must be able to dry to the interior."
Most spray-foam insulations are petroleum byproducts, but Warden says the good from energy savings from a properly insulated home will outweigh the bad. Louisianans also have the option of a more sustainable insulation made from sugarcane byproduct.
However, "all insulations are only as good as they're installed," Warden says.
HVAC. Central air conditioning: Seal the ducts, make sure refrigerant levels are correct (a yearly tune-up should do the trick, scheduled before the busy summer and winter seasons), and change the air filter regularly. These changes can account for a 10 percent to 30 percent increase in efficiency.
Never mind the extra 30 minutes or so it might take to cool the house down when you get home from work — keeping the thermostat at 85 degrees when you leave and bumping it down when you get home doesn't negate the energy saved during the day. Warden also says to make sure you've read your manuals. Know your HVAC.
As for window units, "Generally, the bills are lower," Warden says, but you'll only be cooling one room and will have to tackle the humidity. Follow the above sealing steps, too. Don't install HVAC unless your home has been renovated to support an appropriate wall system. New HVAC systems should be SEER 13 (seasonal energy efficiency ratio) or higher and ... installed correctly.
Shade. Keep the sun away from windows, and for older homes, use solar screens and awnings. Also, replace incandescent light bulbs with compact fluorescents (CFL) — incandescents require more energy and give off heat, which increases the need to cool a space.
Dial it down. Lower your water heater temperature to 110 degrees, or from "hot" to just above "warm." Warden also suggests using a thermometer to check the water temperature, and water heater blankets and pipe insulation also help.
For more information about energy efficiency and vendors, visit www.globalgreen.org/bibg or visit Global Green's Green Building Resource Center (841 Carondelet St., 525-2121). Residents who make 80 percent or less of the median income for the area qualify for a free home energy assessment.