Heating systems come in many varieties. An efficient woodstove can make a great space heater.
Photo courtesy COURTESY VICTORIAN FIREPLACE SHOP
This winter, many people are facing much higher heating bills. The costs of fuel oil and electricity are rising, and natural gas prices are up to 50 percent higher than last year, according to the U.S. Department of Energy (DOE).
As fuel prices rise, it’s tempting to look for the single solution that will shave off a large part of your heating bill, but there are numerous ways to improve the energy efficiency of your home. Many of these are simple, inexpensive steps that can reduce your energy use and bring you immediate savings. You also should keep in mind home improvements that will lead to long-term savings, including purchasing more efficient windows, additional insulation or an energy-efficient heating system. When you’re building a home, remodeling or buying a new heating system, choosing the most energy-efficient options can bring you significant savings over time.
Over the past 12 years, I’ve had the enjoyable job of performing energy audits in thousands of homes, both new and old. What I like to tell people is that energy efficiency shouldn’t be a hardship - in fact, it can be very rewarding. Not only is increasing the energy efficiency of your home a step toward a sustainable use of fuel and less pollution, it also offers you greater security and independence, lower energy bills and can make your home a more comfortable place to live.
Adjust the Thermostat
The most obvious way to reduce your fuel use is to turn down the thermostat. Think of it as a valve between your fuel supplier and your wallet. For every degree you turn it down, you will use up to 3 percent less heating energy. A 10-degree setback overnight or while you’re at work will cut your heating bill by up to 10 percent.
When you use a programmable thermostat, you save energy without even thinking about it - simply adjust the settings to turn the temperature down automatically while you’re away from home. Keep in mind that it doesn’t take long to heat your home to a comfortable level - only about 15 minutes. Never adjust the thermostat above the desired temperature; doing so will not heat your home any faster.
Some heating systems allow you to provide temperature control to different heat “zones” in the house. If you are installing a new heating system, make sure you have enough zone control to keep seldom-used areas of the house at cooler temperatures.
Repair Drafty Windows
Older windows are often big energy wasters. When you’re ready to invest in new windows, many energy-efficient options are available (see High-performance Windows and Install Your own Windows). But before you buy, you should know there are several inexpensive repairs that can improve the performance of your current windows.
When assessing the condition of your windows, look for the number of panes of glass (also called glazing), and how tightly the windows close. If the sashes and frames are rotten, then it’s time to think about new windows. Any drafts you feel when standing next to a window are likely due to air infiltration around the window frame or sash perimeter. Address drafts by installing sash locks and weatherstripping around the perimeter of the window. For double-hung windows, consider side-mounted sash locks that pull the window tight to the sides of the frame, not just where the sash rails meet.
You can remove the inside trim surrounding the window to see how it was installed into the framing cavity. Any air space between the house shell and the window frame can cause significant air leakage and should be sealed. If the gap is not too wide, then it can be sealed with caulk, backer rod or nonexpanding foam. For windows with ropes and pulleys, buy pulley seals to stop air infiltration there.
You can reduce heat loss through windows by covering them with plastic window film or insulating window inserts, such as those available at www.windotherm.com. Another option is to make simple window quilts by sandwiching a piece of Bubble Wrap between two pieces of cloth material, which can be rolled up and down as needed.
Efficient Heating Systems
A typical heating system will last about 20 years, although some have been around much longer. If yours is 15 years old or more, then it is a good candidate for replacement: Efficiency can range from about 60 percent in older equipment to 95 percent or higher in modern systems. The Annual Fuel Utilization Efficiency (AFUE) is a standardized test of a heating appliance’s overall efficiency and is listed on the yellow EnergyGuide tags found on heating equipment. A boiler AFUE rating of 85 percent or better qualifies it for the Energy Star label, while a furnace requires a rating of at least 90 percent to receive an Energy Star label.
But before you buy a new heating appliance, consider low-cost maintenance and relatively inexpensive upgrades, which offer significant energy savings to anyone with a furnace, boiler or combination system.
Maintenance you can do yourself: Preventive maintenance is the best way to maximize the efficiency and life of your heating system. Simple things you can do include:
Keep any air registers, grills and radiators clean and clear. Furniture, drapes, dirt or other obstructions block heat.
If you have a steam boiler and there is noise coming from one of the radiators, or it isn’t producing heat, then you probably need to bleed trapped air from the line.
If you have a furnace, regularly clean or replace the air filter. Do this whenever you can see dust buildup, which may be once a month or more during the heating season. If the air handler (the blower fan) is also used for air conditioning, then service the filter throughout the year.
Clean the furnace blower motor and fan blades when you change the air filter. Only do this yourself if you’re completely sure you have shut off the electricity to the furnace. The fan is usually behind the air filter, but check your owner’s manual.
Check for soot, rust and corrosion in, on and around the furnace and on the floor surrounding it. Such signs indicate the system requires immediate service.
Professional maintenance: To keep your heating system operating smoothly and safely, you will need to have it cleaned, tuned and adjusted annually if it’s oil; every two years if it’s gas. Here are a few things a technician can do during that service:
Remove any excess soot. On oil-heating equipment, even an eighth of an inch of soot on the heat exchanger can increase fuel consumption by 8 percent.
Test the efficiency. Nothing runs at 100-percent efficiency, but if the service technician cannot bring the efficiency up to at least 75 percent, then ask about the costs and benefits of equipment upgrades or replacement.
For a forced-air system, balance the supply and return ductwork. This adjusts the airflow to and from each room for maximum efficiency.
Repair ducts in forced-air systems: Unless ducts are perfectly sealed and insulated, they waste valuable energy and compromise the quality of your indoor environment. Studies of homes across the United States have shown that a modest investment in duct repairs (often about $200) can achieve average annual heating energy savings of 17 percent.
Heat passing through ducts will be readily lost to colder areas because ductwork often runs through unheated spaces, such as basements and attics, and through the interior of outside walls. Air leaks in the supply side of the ductwork allow conditioned air to move into unconditioned spaces, while leaks in the return side can suck air from places such as the attic and basement, circulating this potentially lower-quality air throughout your house. Small leaks can lead to large increases in energy costs, poor delivery of conditioned air, as well as a dusty house and decreased comfort.
A technician can test for air leaks in your ductwork. Typical repairs include sealing all seams with UL-181-approved foil tape or mastic, which meets industry standards for air ducts. Do not use regular cloth duct tape - studies have found that it fails after about six months. Another professional method for repairing ducts is to spray a sealant called Aeroseal into the ductwork. As the product finds its way out of leaks, it expands to seal the hole. After sealing, the ducts should be wrapped with at least R-5 insulation. (R-values measure resistance to the flow of heat; the higher the R-value, the better the insulator.)
Equipment improvements for boilers: Things that a professional heating contractor can do to improve the efficiency of your boiler include:
Install a time-delay relay that allows water to circulate before the boiler comes on. In warmer weather, the warm water already in the boiler may be enough to heat the house.
Install adjustable radiator vents or valves on hot water or steam boilers so you can shut off heat in unused rooms.
Install a modulating aquastat on your boiler to automatically adjust the boiler water temperature based on the outside temperature.
Air Sealing and Insulation
Air leaks between the inside and outside of a building are often the biggest source of heat loss. How do you find the leaks? Sometimes you can feel the drafts; you also can walk around the inside of the house with a smoking incense stick on a windy day and watch for changes in the direction of the smoke. But air leaks are usually hidden, so the best way to find them is to hire an experienced energy auditor. The cost of a home energy audit can vary widely - most are between $100 and $500 - but the expense quickly pays for itself in energy savings. Some utilities and state energy programs offer free or low-cost energy audits; check to see what services are available in your area.
Once you have identified air leaks, many inexpensive options for air-sealing improvements are available. These can include using caulk to fill gaps no wider than half an inch; filling larger gaps with expanding foam; adding weatherstripping around windows, doors and attic hatches; and putting foam gaskets behind outlet and switch plates.
The DOE recommends different R-values for different climates. (Go to www.eere.energy.gov/consumer/tips/insulation.html to search recommendations by ZIP code.) Based on my experience as a home energy auditor, I strongly encourage you to insulate your home to these levels. In fact, local building codes may require higher R-values for new homes than those listed by the DOE. An energy auditor or insulation contractor can tell you how much insulation you have in your walls, ceiling, floors and basement; make recommendations for improvements; and give you an idea how much such improvements will cost.
Spending what may seem like a large amount of money to upgrade insulation in a new or existing home can offer significant savings during the long-term ownership of your home. If your budget is limited, attics are an easy place to add insulation at a minimal cost, and it’s easy to do yourself. Many attics can be insulated to recommended levels for only $200 to $500.
Adapted from The Home Energy Diet: How to Save Money by Making Your House Energy Smart, a Mother Earth News “Book for Wiser Living” by New Society Publishers.