Posted: 10:05 a.m. Thursday, June 13, 2013
By Jerry Kronenberg
BOSTON (MainStreet) — "Green" technology can turn the hot weather baking much of America this summer from a drag on your home's air-conditioning bill to a source of free solar energy — if you know what improvements to make.
"Green upgrades can give you a good return on investment, a lifestyle that's more pleasant and let you feel good about what you're doing to help the environment," says Harvey Sachs, senior fellow at the American Council for an Energy-Efficient Economy.
Sachs estimates homeowners can recoup the costs of carefully chosen energy improvements over five years — and enjoy a much more comfortable indoor climate in the meantime.
"By bringing your home's energy systems under control, you'll get rid of drafts, kill a lot of equipment noise and eliminate rooms that are too hot or too cold," he says. "That's worth a lot right there."
Here's a look at five high-tech moves the expert believes every homeowner should consider this summer to maximize their property's energy efficiency:
Cost figures are estimates for a typical four-bedroom home and were provided by Complete Home Evaluation Services, a Maine energy-efficiency consultancy.
Get a home energy audit
Cost: $200 to $750
Sachs recommends getting a "Home Energy Rating System" review or other comprehensive audit of your property's fuel efficiency before even thinking about installing a solar panel or new air conditioner.
"Instead of just blindly throwing money at energy efficiency, you want to invest in a consultant with the right tools and get the right 'road map' of what to do," he says.
Home-energy audits typically take around a half-day and involve checking your home's heating and cooling systems, as well as using high-tech infrared heat detectors and negative-air-pressure machines to find gaps in your property's insulation.
Audits typically cost a few hundred dollars, but your local utility or state energy commission will sometimes offer them for free or at a reduced cost.
Fix your home's "envelope"
Cost: $4,000 to $5,500
Once you've done an energy audit, you should fix any gaps the review has uncovered in your home's "envelope" — the insulation that separates heated or cooled living spaces from unheated attics or the outdoors.
"Getting the envelope right is the first step toward getting the smallest energy bills possible," Sachs says. "Fix the envelope and you've maximized your freedom to do anything else you want, whether you're just improving the air conditioning or putting in solar heat."
DeWitt Kimball of Complete Home Evaluation Services says air leaks account for 50 percent or more of a property's energy loss, and sealing them helps heat and cool a property more efficiently.
"People think you just insulate a home for the winter, but I get rave reviews in the summer from customers who say: 'It's unbelievable how much more comfortable my house is,'" he says. "Good insulation keeps the summer heat out and the cool in."
In addition to cutting your energy bills, eliminating air leaks will allow you to install smaller heating or air-conditioning systems — saving you even more cash.
Sachs added that you won't have to fix insulated air ducts, which typically let some 30 percent of your system's heat or coolness escape. If you have a well-sealed home, hot or cold air that leaks from these ducts will simply stay inside the house.
Add a high-efficiency heater/air conditioner
Sachs advises installing a high-efficiency combination heater/air conditioner if your home has an older, inefficient model.
Consider replacing any furnace or boiler that's more than 15 years old and has an 80 percent or lower annual fuel utilization efficiency rating.
You also want to think about replacing older forced-air or hot-water systems that lack modern "condensing" capabilities. That's where your furnace or boiler recaptures heat from the system's hot water or flue gases as they cool and condense.
Also replace any aging air-conditioning system with a new unit that includes a variable-speed fan and either a two-stage or variable-modulating-speed compressor (also called an "inverter drive compressor").
Basic central-air systems have just "on" or "off" positions, but two-stage units have "high" and "low" settings and variable-modulating systems essentially have an infinite set of speeds. Coupled with a variable-speed fan, such advanced systems can independently control your home's temperature, humidity or both — keeping you comfortable whether it's warm and muggy or hot but dry.
Best of all, Sachs says, such units also typically run at low speeds 80 percent or 90 percent of the time. That will save you big bucks over single-speed systems, which run full blast even when it's only a tad hot out.
Install a solar water heater
Cost: $10,000 to $12,000
You can take advantage of the summer sun by installing a solar water thermal heater on your rooftop to heat water for free.
These units basically pipe water onto your home's roof where the sun heats it, then transfers water to an indoor water tank for later use.
"A solar thermal water-heating system will give you free hot water all summer long — and most of the winter, too," Sachs says.
The only downside is its hefty cost — around $10,000 and up, according to Complete Home Evaluation Services.
Sachs concedes that at that price, installing a solar water heater is "not likely to be quickly cost effective."
Add photovoltaic electricity
Cost: $14,000 and up
The sunlight baking so much of the country this summer contains more than enough energy to meet many homeowners' needs — if they install photovoltaic roof panels to turn it into electricity.
These systems are expensive, but Sachs says you can cut costs significantly by installing photovoltaic panels that produce enough electricity for most but not all of your power consumption.
"Trying to meet your home's entire electric load with solar power instead of relying on your local utility for the last little bit can easily double the cost of a system," he says. "You might only have a couple of hundred hours a year when you use the maximum amount of air conditioning. But if you decide to size your solar unit to meet that load, you'll need a much larger photovoltaic system."