Smarter Living: Energy
Cold Weather Planning: Seven Steps to a Warmer Home
Photo: Andrea R/Flickr
As winter nears and the nights take on a chill, you may find yourself dreading the arrival of your energy bill. Driving that bill down, however, just requires taking a few steps to make your home more efficient. By spending a little now, you can keep yourself from losing a lot later when energy prices rise. The key is to look at your house as a system, from its exterior envelope in, and to prioritize the changes that will give the most return for the cash spent. Here is a step-by-step plan to winterize your home effectively. You may not be able to afford every step, but following them in order will give you the biggest payback for the expense.
Start with the Basics
Regardless of the time of year and what upgrades you may be able to afford, getting rid of wasteful habits will cut your energy bill.
Here are five basic habits to adopt:
1. Don't leave lights on. Install a motion-sensing light switch if you have to.
2. Unplug chargers and appliances when not in use. If this is too much of a bother, there are power strips available that turn off automatically when applicances aren't in use. See our Energy Vampire Calculator to determine how much money you may be wasting now.
3. Make sure you're operating your TV for home use rather than for a display floor. If the screen is super bright, dim it down to a comfortable level. See "Power-Hungry Televisions" for more information.
4. When washing your hands or soaking pans in the kitchen, turn hot water taps up to full heat rather than halfway to ensure that the hot water gets to you quickly. If you turn the taps up only halfway, hot and cold water mix in the pipes, and as a result it takes much longer for the water to arrive at the temperature you want it. In the meantime, all you've done is warm up the pipes.
5. Line-dry your clothes. Clothes dryers are a major energy hog in the home (our Clothes Dryer Calculator will tell you how much yours uses). But if your home is well sealed and insulated, fabrics will dry quickly hanging on a rack or indoor line. Which leads us to our first step.
Step One: Arrange for a Home Energy Audit
A home energy audit will determine how efficient your house is and where you can make improvements. You may already know whether your furnace is working poorly, or you may be aware of drafts near your front door, but other major sources of heat loss are much harder to identify. Problems can include poorly insulated walls or cold flows from direct openings to the outdoors in your attic or other hard-to-access spaces. Certified raters will track these problems down and propose solutions. If you're going to be comprehensive about it, the $300 to $500 for a home energy audit is money well spent. Certified raters and contractors in your area can be found through listings at the Building Performance Institute and at the Residential Energy Services Network.
The energy audit will provide you with a HERS rating of your home. This index ranges from zero to over 150, with the standard home hitting about 100. While this number helps give you a sense of where your house stands, the real benefits come from the detective work done during the audit to trace exactly where your house is wasting energy. For any audit, make sure your rater walks through your home, conducts a blower door test (which measures how much air your home leaks), tests your ducts, checks out your furnace and identifies colds spots and the locations of air leaks.
To see how much specific upgrades suggested by the audit might save you, fill out the Home Energy Saver questionnaire provided by the Lawrence Berkeley National Laboratory. The U.S. Department of Energy provides an online guide to home energy audits that is helpful whether you choose to do it yourself or hire a professional.
Step Two: Install a Programmable Thermostat
This is an easy and cheap way to improve the efficiency of your current system. Programmable thermostats will automatically dial down the temperature when you're asleep or away at work and boost the heat when you need it. Once you've programmed the settings, you won't need to bother with it again until the season changes.
Just remember that if you replace your old thermostat yourself, you should check to see if it has a mercury switch. These are easily recognized: Look in the interior of the old thermostat for a glass capsule with a ball of mercury. If you find one, contact your sanitation department about household hazardous waste (HHW) disposal, or enter your zip code at Earth911.org to find out where to bring HHW in your area.
Step Three: Seal and Weather-Strip
In a cold climate, keeping warm air inside is essential to maintaining comfort. The contractor or rater will have a general idea of the steps you should take to do this, and you should follow the rater's expertise.
Weather-strip windows and doors, and caulk any leaks found in the audit. Be sure to scrape any areas with peeling paint and remove old caulk beforehand. For windows, you'll want to use a wood filler on cracks and holes larger than an eighth of an inch. You'll also need to scrape away old, cracked glazing putty and replace it with fresh glazing putty. For a thorough sealing job, it's often best to have a contractor handle it since sealing ductwork and other areas can be tricky.
Step Four: Add Insulation
Insulating is a more costly and time-consuming task than sealing. While you may be up for adding batting to your attic or stapling up rolls of it in your basement, insulating walls is a job for a professional and may be a significant investment. However, the savings can be as much as 30 percent of your heating bill. And remember that what keeps you warm in the winter will keep you cool in the summer.
Ductwork: Insulate any duct not in the heated area.
Walls: Put in as much insulation as will fit.
Attic: Add at least a foot of insulation, and increase depending on your climate zone. A good rater might be able to recommend how much, but one foot should be your minimum starting point.
Water heater: Insulate older water heaters, which suffer standby heat losses. Newer heaters are better insulated and function more efficiently.
Preserve your indoor air quality: Look for products with no VOCs. There are many formaldehyde-free fiberglass insulation prod/ucts now available. Ask for no-VOC polyurethane spray foam if you are having a professional inject insulating foam in your walls.
Step Five: Upgrade Your Furnace
As part of an energy audit, you should have already checked your furnace's efficiency. But you can easily get a baseline by looking for the annual fuel utilization efficiency (AFUE) rating on the side of your furnace, which should be at least 70 percent. Keep in mind, however, that the current minimum for new non-condensing, fossil-fueled, warm-air furnaces is 78 percent. And Energy Star-qualified oil and gas furnaces have a minimum rating of 85 and 90 percent, respectively. If your furnace is so old it doesn't have a rating, you might well consider replacing it, especially if it is malfunctioning. It may turn out that for the price of fixing it you could buy a new one.
Indeed, there can be significant gains from upgrading. Condensing gas furnaces use waste heat that would otherwise escape through an exhaust vent, passing it through a heat exchanger for added warmth. You may also switch from fuel oil to natural gas if you can get a gas line run, which will help you escape the price volatility of oil. There are also tax credits available for more-efficient oil stoves and wood or pellet stoves (see "New Energy Efficiency Tax Credits" for information on how to qualify). Assuming you get a good contractor, you should be able to keep emissions down.
One step you won't want to make, however, is a switch from oil to electric heat. Since the electricity supplied to most American homes is generated by coal, the emissions associated with it are worse than those coming from a natural gas or oil furnace. Don't be confused by the efficiency ratings for electric furnaces; they are measured in a fashion completely different from the ratings for oil stoves.
Finally, if you seal up your home well, you may be able to get a smaller furnace. Ask your rater to provide an assessment of the smallest furnace you can get away with, though keep in mind that there's a strong element of personal comfort involved in this choice.
Step Six: Buy More-Efficient Appliances
As you work your way inward, next come appliances and lighting. Where possible, you should replace your bulbs with compact fluorescent lightbulbs (CFLs) or efficient halogens.
As for appliances, the good news is that it doesn't matter what time of year you replace the inefficient ones. This allows you to concentrate on the first five steps now, giving you time to save money for the energy-efficient appliances of your dreams.
Those you should consider replacing include:
Refrigerator: Refrigerators are among the top energy-consuming appliances in the home. Especially if your fridge dates back to 2000 or earlier, a new refrigerator will provide you significant savings. To see how much a new Energy Star-qualified model will save you, use our Refrigerator Calculator.
Water heater: This is another significant energy user, but newer models employ condensing technology like that described for furnaces. If possible, replace an electric water heater with an Energy Star-qualified natural gas model, which can cut energy consumption by half. And even though gas models can operate for up to 25 years, after 10 years their efficiency can decline to less then 50 percent, making an upgrade cost-effective. For more information on options, see Salvage or Scrap: Water Heaters.
Television: TVs are also a significant user of energy and have long been unregulated for efficiency, resulting in a large number of power-hungry machines. Energy Star recently updated its rating system for televisions; qualifying sets will use about 30 percent less energy than standard models of the same size. However, the new requirements won't become effective until May 2010, so you might want to delay a new purchase until that time.
Step Seven: Replace Your Windows
You might think windows would be among your first targets when tightening up your home, but when it comes to what you get for your money, they are far down on the list. True, efficient windows will save energy, but taking the previous steps first will save more. If you are going to replace your windows anyway, look for National Fenestration Rating Council-rated windows. Check the U-factor, which measures how much heat can escape, and the solar heat gain coefficient (SHGC) rating, which measures how much heat from sunlight is transmitted through a window. In colder climates you want the U-factor to be as low as possible, but you also want a decent SHGC rating, since keeping that heat out will help prevent you from reaching for the AC.For more on choosing windows as well as money-saving low-emissions films you can apply to your current glazing, see Energy Out the Window?
last revised 10/4/2011