Ask Energenie

November 1999

Table of Contents

1. What's the most important thing I can do to save energy in my home this winter?
2. What is the best way to weatherproof an old double-hung window for the winter?
3. How often should I have my heating system serviced, and what should a professional inspection include?
4. As a renter, what can I do to reduce utility costs this winter?
5. I'm shopping for a portable electric heater. The prices vary from about $20 to more than $200. Are the higher-priced heaters more efficient?
6. How can a light bulb that costs $20 ever compete with one that costs 50 cents, even if it only uses one-fourth the energy?

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1. ?

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What's the most important thing I can do to save energy in my home this winter?

"The key is to simply be aware of how much energy the components of your home use," replied Doug Walter, president of Kansas Building Science Institute.

"The biggest energy users often are out of sight and make little noise, and you don't directly operate them," Walter said.

For example, your water heater may be hidden away in a basement room, makes little if any noise and is never turned on by the user. Yet this appliance consumes from 15 to more than 20 percent of total household energy use in a typical home.

By contrast, lighting, which is highly visible and which you control by flipping a switch, consumes about four percent of household energy use. So, while turning off unnecessary lights and using efficient light sources will save energy, these measures won't knock a large hole in your monthly energy bill.

"The biggest chunk of your energy bill this winter will go to keeping your house warm," Walter said.

How warm you choose to keep your house determines how much energy you will consume. One degree of temperature change affects your energy use by about three percent.

So, maintaining your house at 68 degrees instead of 71 degrees will save almost 10 percent on your monthly energy bill. A 10-degree setback at night will also save about 10 percent on energy use.

If you have an automatic thermostat, your body will never detect the temperature difference. Your house will be warm when you go to bed and when you get up because the temperature drops only while you are sleeping.

"The following tips will help you save the most energy by cutting back in areas of major consumption," Walter added.

• Maintain the lowest comfortable setting on your thermostat.
• Reduce the thermostat setting 10 degrees at night.
• Reduce your water heater temperature to 120 degrees.
• Install flow-reducing showerheads and faucet aerators.
• Wrap your water heater with an insulation kit.
• Seal major air leaks in doors, windows, electrical outlets in exterior walls, openings to the outside and openings into the attic.

If your bills are still higher than you think they should be, you might want to consider having a comprehensive energy analysis done on your home. This analysis, conducted by a certified energy rater, includes a blower door test which will locate major air leakage pathways which can otherwise be difficult to find. The energy rating report you receive will include a list of energy-saving measures specific to your house, along with an estimate of their cost and projected energy savings.

For a list of certified home energy raters, call the Kansas Housing Hotline at 1-800-752-4422.

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2. What is the best way to weatherproof an old double-hung window for the winter?

"Double-hung windows are a common energy drain in older homes," said Bruce Snead, extension specialist in residential energy at Kansas State University. "But you can plug that drain by applying the following simple measures."

Basic maintenance of double-hung windows should include fixing cracked glass, puttying and replacing loose window locks with those that clamp the upper and lower sash together. Close storm windows and clean out condensate holes on the bottom frame to allow free drainage.

Apply compression weather-stripping under the bottom sash and place v-fold weather-stripping between the sash and frame and upper and lower sashes. Snead said this will help control infiltration and still let you open and close the window.

"Temporary or seasonal 'fixes' like weather-stripping and caulking windows can pay for themselves in energy savings within one heating season," he added.

Use rope caulk or strippable caulkinq materials to seal all joints between the sash and frame.

Another energy-saver, interior storm windows, serve a dual purpose — they control infiltration and reduce conductive heat loss. The most common types are heat shrink films and vinyl sheets held in place by a track and gasket system.

"These methods work well for windows that have moisture condensation problems," Snead said.

Condensation occurs when air cools to a temperature below the dew point, or the temperature at which air can hold no more moisture. Insulating with heat shrink film or vinyl raises the window's surface temperature and reduces condensation.

You can also reduce heat loss by insulating windows with shades, shutters, drapes or curtains.

"You can make your own low-cost shutters from foil-faced insulation board, weather-stripping and duct tape," he said.

Homemade shutters are suitable for rooms that are rarely used, and they may increase comfort in rooms adjacent to large window areas.

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3. How often should I have my heating system serviced, and what should a professional inspection include?

"You should have your heating system professionally inspected at least every other year, or whenever you suspect a problem or detect poor performance," suggested Doug Walter, president of Kansas Building Science Institute, Manhattan.

Walter said a furnace technician should do the following when inspecting or servicing your system:

• Check for leaks in the gas supply piping to all combustion appliances.
• Visually inspect the venting system for proper size and vertical rise. Check for blockage, restriction, leakage, corrosion, or other unsafe conditions.
• Inspect the burners and crossovers for blockage and corrosion.
• Test the heat exchanger for cracks, openings, and corrosion.
• Check the pilot for proper operation and verify that main burner ignition is satisfactory.
• Test the pilot safety device (thermocouple) to determine that it is operating properly.
• Test for spillage of combustion products at the draft hood.
• Check for carbon monoxide in the flue gases.
• Remove and clean the burners and adjust the primary air as necessary.
• Check for proper temperature rise through the furnace. Clean the blower and adjust the blower speed as necessary. Clean or replace the filter.
• Check the limit control and fan control for proper operation.
• Calibrate and adjust the thermostat.

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4. As a renter, what can I do to reduce utility costs this winter?

"Energy conservation may result in a direct cost savings if your apartment is individually metered for energy use, or indirect savings if energy costs are included in your rent," said Richard B. Hayter, director of Engineering Extension at Kansas State University.

Obvious opportunities for conservation include carefully controlling the thermostat while the apartment is occupied, and setting it to a lower temperature when the apartment is empty.

Close drapes in the evening and during times when there is no benefit from direct solar gain. Doing this will reduce heat loss through the windows and possibly decrease infiltration of unwanted air.

"For even better control of infiltration, consider buying removable caulking or weather-stripping," Hayter said.

Visit with your landlord before making any physical changes to the apartment.

Hayter said appliances also add to utility costs.

"Microwaves generally use less energy than conventional ranges, so try to do most of your cooking in the microwave," he said.

Refrigerators are also high on energy use, and they require even more energy if the condensing coils are covered with lint and dirt. To increase the efficiency of your refrigerator, clean condensing coils (located beneath or behind the refrigerator) regularly.

"Use kitchen and bath exhaust fans to remove excess moisture and cooking odors," Hayter said. "Do not use fans excessively, however as this will draw cold outside air through your apartment."

Lighting may not be a significant part of your utility bill, but you should still conserve whenever possible.

"Conservation in the area of lighting does not mean just turning off lights when you leave a room," Hayter said. "You can save energy and money by using more efficient bulbs."

For example, if you are going to replace a fluorescent tube in a fixture, use an energy-efficient replacement. The energy efficient bulb will cost more initially, but its longer life and increased efficiency will more than compensate for the additional cost.

Likewise, if you replace two bulbs in a fixture with a single, higher wattage bulb, you will save energy. A 100-watt bulb provides about the same light output as two 60-watt bulbs, using 20 fewer watts of electricity. Also, consider replacing the incandescent bulbs with a compact fluorescent if the lamp is not on a dimmer switch.

"Anytime you replace incandescent light bulbs, make sure the bulb does not exceed the maximum wattage recommended for your fixture," Hayter added.

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5. I'm shopping for a portable electric heater. The prices vary from about $20 to more than $200. Are the higher-priced heaters more efficient?

"No," replied Doug Walter, president of Kansas Building Science Institute, Manhattan. "All portable electric heaters are essentially 100 percent efficient."

"They can't operate at more than 1,500 watts, since this is the maximum for most household electric circuits," he said. "At this wattage, a heater will produce 5,120 Btu of heat an hour."

At the bottom end of the price range, electric heaters are typically small electric fans mounted behind a coiled wire.

The coiled wire "resists" the flow of electricity through it, creating heat.

The fan removes the heat from the wire and circulates it into the room. The heater may have two or more heat settings and a fan-only setting.

Higher-priced models include thermostatic control and safety features such as an automatic shutoff in case the heater tips over. Often even these models are discounted to $20 or less.

"The very high-priced models, like possibly the $200 heater you found, often contain a heat storage medium, such as water or oil," Walter said.

"They use an electric heating element, like one found in a water heater, to heat the oil or water. As the liquid circulates through a coil, room air blown over the coil is heated."

Claims for these products often imply greater efficiency and comfort, but there is no basis for these claims.

Walter said one variation in electric heater design that can provide comfort at a lower operating cost is a radiant heater.

This type of heater contains one or two quartz heating elements mounted in front of a reflective surface.

"The heating elements provide instant radiant heat to people or objects within line-of-sight of the heater," he said. "Thus, there is no need to raise the air temperature in order to provide comfort."

Quartz radiant heaters typically cost from $40 to $70.

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6. How can a light bulb that costs $20 ever compete with one that costs 50 cents, even if it only uses one-fourth the energy?

"I believe you are referring to one of the new compact fluorescent lamps," said Gene Meyer, extension mechanical engineer at Kansas State University. "To answer your question, I came up with the following example."

Suppose you replace a 75-watt standard incandescent lamp with an 18-watt compact fluorescent. If the lamp is used just six hours a day, the compact fluorescent will save nearly $9 a year in energy costs (based on a rate of 7 cents per kilowatt-hour).

Operating six hours a day, the fluorescent light will last about five years.

In the same five years, you will have changed that 50-cent bulb 13 times.

So, over a five-year period, the incandescent would cost $64 ($6.50 for bulbs, $57.50 in energy), compared to $33.75 ($20 for bulb, $13.75 for energy) for the compact fluorescent. The total savings over the life of the fluorescent would be $30.25.

"The savings will be even higher in areas where electric rates are above 7 cents per kilowatt-hour," Meyer added.

In addition to energy cost savings, because the compact fluorescent lamp uses less energy, it will cause less greenhouse gases to be emitted from the power plant. Over its life, the compact fluorescent will reduce carbon dioxide emissions by about 1,200 pounds.

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Ask Energenie is produced by the Kansas Energy Extension Service through Kansas State University. This material was prepared with the support of the U.S. Department of Energy (DOE) Grant No. DE-FG48-97R802102. However, any opinions, findings, conclusions, or recommendations expressed herein are those of the author(s) and do not necessarily reflect the view of DOE.