Ask Energenie

April 1999

Table of Contents

1. What does a SEER rating on air conditioners mean and how do I compare ratings between units?
2. What trees are the best for summer shading? I want a tree that grows fast and doesn’t litter the yard.
3. The majority of my house’s window space is on the south. Now that summer is approaching, the solar gain will increase my air conditioner’s load, thus driving up my utility bill. What are some inexpensive ways to cool my home without running the air conditioner constantly?
4. What should I do to keep my gas water heater operating at maximum efficiency?
5. What is meant by the term "waste to energy"?
6. I recently tested for radon and discovered that my home has an elevated level. Now what? Where can I find a qualified contractor to fix my radon problem?
7. Should I shut off the pilot light on my furnace during summer?

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1. What does a SEER rating on air conditioners mean and how do I compare ratings between units?

"SEER stands for Seasonal Energy Efficiency Ratio," said Richard Nelson, extension specialist at Kansas State University. ''This rating measures how well an air conditioner uses energy throughout the cooling season."

The SEER is equal to Btu of cooling supplied during the year divided by kilowatt-hours of electricity consumed in a year. The higher the SEER rating, the more efficient the air conditioner.

Nelson gave the following example, "A unit with a cooling capacity of 24,000 BTU that consumes 2,400 kilowatts of electricity would have a SEER of 24,000/2,400, or 10."

"Units with high SEERs will cost more initially, but the energy savings throughout its lifetime will more than make up for the cost difference," Nelson said.

"When comparing SEER ratings of different air conditioners, compare only those with similar capacities (Btu)," he added.

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2. What trees are the best for summer shading? I want a tree that grows fast and doesn’t litter the yard.

"Unfortunately, there is no variety of tree that grows overnight and has absolutely no debris," said Gene Meyer, extension mechanical engineer at Kansas State University. "But with some research, you can find a variety that requires less maintenance and has a relatively short growing span."

Kansas has a wide variation in temperature and rainfall. As a result, no single tree is best suited for shading your home.

"Contact your local county extension agent for help in selecting and planting shade trees," Meyer suggested. "While you are at it, consider planting a windbreak to reduce winter heating costs."

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3. The majority of my house’s window space is on the south. Now that summer is approaching, the solar gain will increase my air conditioner’s load, thus driving up my utility bill. What are some inexpensive ways to cool my home without running the air conditioner constantly?

"The simplest, least expensive method to keep your home cool is shading — of walls, windows and roof," said Richard Nelson, extension specialist at Kansas State University.

"Interior shades are inexpensive and easy to install," Nelson said. "Use pull-down or Venetian blinds in addition to regular window coverings." He added that window coverings should be light-colored (white or beige).

"There are several ways to keep your home cool without overusing the air conditioner. Of these options, install shades first," Nelson said. "Compare utility bills before and after you install shades. If you are satisfied with the savings, you can stop there, but if savings are not significant, look into other options."

"One option you should consider is exterior awnings," he said. "They are more expensive than interior shades, but would be a great way to shade your south and west windows."

"Natural shading is another way to block heat gain in summer," Nelson said. "Plant broad-leafed trees on the south and west sides of your home. They shade your home in summer months and will let in sunlight during winter months when they have shed their leaves."

"Certain steps you take to keep your home warm in winter will help cool it during the summer," Nelson added. "Insulated walls and roof reduce heat gain, just as they lower heat loss in winter. As a general rule, ceiling insulation should have an R-value of 35 to 45, and walls from 19 to 27."

A light-colored roof also decreases heat gain. "Reroofing means sacrificing more time, effort and money than other cooling options — unless you need to reroof your home anyway," Nelson said.

"Use the above suggestions, coupled with circulating fans inside your home, and your utility bills will be less than if air-conditioning was your only cooling source," Nelson said. "In some cases, shading alone can achieve a comfort level that suits you."

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4. What should I do to keep my gas water heater operating at maximum efficiency?

"As with any heating or cooling device, regular maintenance of gas water heaters goes hand in hand with efficiency and safety," said Gene Meyer, extension mechanical engineer at Kansas State University. "Follow these three steps to assure your water heater is giving you maximum efficiency for minimum dollars."

1. Every two months, connect a hose to the bottom drain. Open the valve all the way, letting the water flush through. Be careful: This is hot water! This removes sediment, which reduces heating efficiency.

2. Place a bucket under the temperature and pressure (T-P) relief valve discharge, located on the top or side of the heater. Carefully lift the lever — again, the water surging out will be hot. The T-P valve is a safety valve designed to prevent the tank from exceeding safe temperature and pressure levels. This test assures that sediment is not blocking the T-P valve.

3. Annually inspect the heater's burner area, checking for dirt or water. If the area is dirty, shut off the pilot and clean the burner with a shop vacuum. Remember to light the pilot again. If there are signs of leaks, you will probably have to replace the water heater soon.

"If your water heater is over two or three years old and you have never checked the bottom drain and T-P valve, they may not seal properly once opened," Meyer said. "You may have to replace either valve if they do not seal tight after operation."

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5. What is meant by the term "waste to energy"?

"Waste to energy is the process of converting waste products that we generate, such as garbage, into energy," said Richard Nelson, extension specialist at Kansas State University.

The most common means of recovering energy from waste is to capture the gases, namely methane, from landfills.

The gases are formed by the degradation of waste over time. As landfill waste is covered with more waste or dirt, it remains in an oxygen-free, or anaerobic, environment. Under anaerobic conditions, waste decomposes and forms several gases, the main one being methane, or natural gas.

Methane gas naturally escapes through the soil cover and into the atmosphere. You can capture this gas and burn it. The resulting heat can provide steam for heating or for running a generator.

"This waste to energy method has positive effects on the environment," Nelson added. "Methane is nearly 20 times worse than carbon dioxide in retaining heat within our atmosphere. By capturing this landfill gas, we are reducing global warming as well."

Some farms use this waste-to-energy technology by generating heat or electricity from low-grade methane that is produced by animal wastes.

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6. I recently tested for radon and discovered that my home has an elevated level. Now what? Where can I find a qualified contractor to fix my radon problem?

For a listing of contractors in the Kansas service area, contact the Radiation Control Program at the Kansas Department of Health and Environment, 1-800-693-5343, or on the Web at http://www.kdhe.state.ks.us.

If you have access to the World Wide Web, you can see listings of radon measurement and mitigation contractors with the National Environmental Health Association at http://www.neha.org

The National Radon Safety Board also has information on radon measurement and mitigation certification at http://www.nrsb.org

"This helps you, the consumer, identify competent mitigators," said Bruce Snead, extension specialist in residential energy at Kansas State University.

As participants in these programs, contractors must follow EPA radon mitigation guidelines. These guidelines give consumers a basis for comparing bids for service.

In addition to the mitigation guidelines, contractors must fulfill other requirements of the programs, which includes training, exams and continuing education requirements.

"Also, contractors must maintain records for the mitigation systems they install," Snead said. "The records must include date, type, and results of measurements; ZIP code of measurement site; mitigation system type and plan of installation; and date of installation."

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7. Should I shut off the pilot light on my furnace during summer?

"If you are interested in saving on your utility bill, yes, shut off the pilot light during the summer," said Gene Meyer, extension mechanical engineer at Kansas State University.

A pilot light will use about one thousand cubic feet (MCF) of gas a month. This means a summer saving of $10 to $20.

"You have nothing to lose and a little to gain by turning off your pilot light in summer," Meyer said. "The pilot does not keep the furnace dry, and it adds heat that the air conditioner must remove."

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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.