Use insulation for year round energy savings
When summer finally graces northern Minnesota and the heat is on, your first instinct to keep your home cool and your family comfortable may be to turn up the air conditioner.
Sarah Hayden, with Creative Energy Services, said there are more environmentally friendly and cost saving alternatives.
There are many ways to keep your home cool during the summer that don’t include cranking the thermostat down and your electric bill up, Hayden said. Many of these solutions are cheap or even free. There is assistance for many of those that aren’t, and almost all of them will pay for themselves over time.
The most vital step in decreasing summer energy costs is to become acquainted with your energy uses and inefficiencies.
“That’s always your starting point, to know as much as you can about how you are using it (energy) and what options are available,” Hayden said, “which is why I always recommend having a home energy audit done because almost everybody is surprised by at least one or two things in the audit — even people who feel very aware and knowledgeable about their home and how it works.”
Home energy audits can identify where you are spending most of your money on energy. This can include inefficient lighting sources, low-efficiency appliances, energy-saving habits and even insulation problems.
The last of these is not only vital to keeping heating costs low during the winter, but also to keep cooling costs low during the summer.
“A lot of the things that you are going to be doing are going to benefit you all year round, regardless of summer, winter, spring and fall,” Hayden said. “In fact, the most important thing in keeping your house cool is to have a very well insulated attic.”
Minnesota can experience hot and humid summer days, but also benefits from many cool summer nights. Hayden said homeowners can take advantage of nighttime temperatures for free cool air that can last throughout the day.
“Any time the outside temperature drops below 70, if you have a well insulated, well sealed house, and you are a conscientious user of your house, there’s no need for air conditioning,” Hayden said. “The biggest thing I will say for saving on your air conditioning bill is to take advantage of the natural cooling that we have by having your windows open at night, airing out and cooling your house, closing them during the day and keeping that cool air in.”
With insulation, there are a few issues to keep in mind. The first is the “R-value” of your insulation. This is the number used to measure your insulation’s resistance to heat.
If your R-value is high, heat will not easily pass through your attic and into your house during the winter, or from your house and out through your attic during the summer.
Locally, the recommended R-value is at least R-50. For cellulose insulation, this can mean 16-18 inches of insulation. For fiberglass it can be even more, but the thickness of your insulation isn’t all that you need to consider.
“Of equal importance to the depth of insulation in your attic is making sure you don’t have any air leaks in your attic. If you have anyplace where the air from your attic can go around the insulation and go into your house or vice versa, then that is going to be a huge heat loss in the winter and a huge opportunity for the heat to come into your house in the summer,” Hayden said.
These air leaks can be common in older buildings, but even newer construction projects can have them. They are often found around features or items that pass through your attic, which can include chimneys, plumbing, access doors, cabinets and electrical conduits.
“Each one of those can make a hole where air can pass through. Each one of those should be sealed very tightly, and often they aren’t,” she said.
Sealing these leaks isn’t as simple as stuffing them with insulation, as air can still pass through. Instead, spray foam and caulk are commonly used, though Hayden mentioned that fireplace flues need special care to prevent fire hazards. Even so, insulation is only part of the process.
“Your strategy for keeping your house cool in the summer requires that you keep the cool in, and not add any heat to your house,” Hayden said.
It is important to remember that light fixtures, appliances and cooking can produce heat in your home. You can decrease this heat by cooking outside, eating cold foods or those that require less heat to prepare, venting appliances that produce heat, drying clothes on a line, and even switching to high efficiency light bulbs.
“Any light bulbs you have left that are still incandescent, switch them to compact fluorescent or, if for any reason you don’t care for compact fluorescent, go right to the more expensive but higher quality LED lights,” Hayden said.
High efficiency bulbs will not only lower electricity costs, but they will also produce less heat in your home. As little as 5 percent of the energy used by incandescent light bulbs is actually light, as they can use more than 90 percent of that energy to produce heat energy.
It is for this reason that these same bulbs are used to make children’s ovens.
Compact fluorescent bulbs, on the other hand, can produce up to 75 percent less thermal energy and equal light, yet use less energy overall. LEDs are even more cost effective and efficient. Furthermore, compact fluorescent lights and light emitting diodes (LEDs) each last much longer than incandescent bulbs.
“LEDs in theory will last forever. They don’t have any gas or filament to burn out in them,” Hayden said. “Of course, in practice the electronic components can break, but there’s not an expiration date, expected lifespan on the LED bulbs. They are intended to last 10 years or more.”
Considerations include keeping doors and windows closed to preserve cool air, closing curtains and blinds, using light-colored shingles and siding, and surrounding your home with light colors on decks and driveways that don’t absorb heat.
In a home with a finished basement, if you have a ceiling fan, there is often a switch that can turn the blades the opposite direction, drawing cold air up from the basement for less cost than an air conditioner, or you might just position a fan in a stairwell.
Overall, before you undertake any project, you should carefully plan first.
“If you’re going to be spending a few thousand dollars on your house, spend it on the project that you’re going to get the most return out of,” Hayden said. “Start there. It’s another reason to get an audit and help prioritize those and spend your money wisely.”
Many of these home improvements can continue to save you money year-round. A well insulated home will continue to cost less when it comes time for heating during the winter, and light-colored shingles can often contribute to fewer ice dams on your roof, which can prevent damage to gutters and roofing.
“I really encourage people to take effort and time to consider their energy use. It’s something that pays off monetarily, and with your conscience and future, too,” Hayden said.
(Sarah Hayden is certified as an Energy Manager through the American Association of Energy Engineers. She conducts home energy audits and is a consultant on energy efficiency projects and project management.)