Ask Energenie

March 1999

Table of Contents

1. I think I qualify for low-income weatherization assistance, but before I apply, I'd like to know exactly what would be done to my home.
2. I bought several 32-watt fluorescent lights for a standard four-foot fixture. Why is there a short delay if I try to relight them immediately after I turn them off?
3. How can steam trap maintenance reduce energy costs?
4. What are low-emissivity windows, and what are their advantages?
5. I have heard that radon levels may be high in private well water supplies. Can I safely drink the water?
6. What can you tell me about the new front-loading washing machines?
7. I am building a new home and an insulation specialist advised me to install a vapor barrier. What is a vapor barrier and how can I install it?
8. We have been advised to add a chemical treatment to our school's hot water heating system. What should we use?

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1. I think I qualify for low-income weatherization assistance, but before I apply, I'd like to know exactly what would be done to my home.

"The measures you can expect will depend primarily on the age, type and construction of your home," said Doug Walter, president of Kansas Building Science Institute, Manhattan.

"Weatherization measures are installed according to priorities, the first of which is heat waste," Walter said. "Heat waste includes air leakage, the heating system and the water heater. The second priority, insulation, includes your attic, walls and floors. Priority three is storm windows, and four is skirting for mobile homes and other miscellaneous items."

Different weatherization measures exist for each of the four priorities.

In addition to furnace filters, water heater wraps and hot water pipe insulation, priority one measures include using a blower door to find and seal air leaks.

A blower door is a large fan temporarily mounted in an exterior doorway. An expandable frame seals the fan into the opening, allowing it to pressurize or depressurize your house, depending on the direction of airflow. Pressure gauges tell how much air is flowing through your house.

"A blower door is a powerful tool that can lead a skilled auditor to all the major air leakage pathways in your house. It can also help the air sealing crew avoid making your house too tight," Walter said.

"When the weatherization crew uses a blower door to find leaks, much of their efforts will be hidden," he said. "You may see little weather-stripping and exterior caulking. Instead, the crew may spend more time in the attic sealing normally hidden air leaks, but the results will be much more effective at saving energy and improving comfort."

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2. I bought several 32-watt fluorescent lights for a standard four-foot fixture. Why is there a short delay if I try to relight them immediately after I turn them off?

"Failure to immediately relight may be inconvenient, but does have its purpose," said Gene Meyer, extension mechanical engineer at Kansas State University.

At least one manufacturer of fluorescent lamps has installed a small temperature sensitive switch in its tube. After the lamp has warmed up, the switch disconnects the power from the portion of the lamp that starts, or "lights" it.

"This disconnection reduces lamp power by approximately two watts," said Meyer. The lamp must cool down about one minute, allowing the switch to close, before it will relight.

Meyer added, "These lamps work especially well in fixtures that are not switched often."

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3. How can steam trap maintenance reduce energy costs?

"Steam is an efficient heating medium and many schools and businesses use it," said Gene Meyer, extension mechanical engineer at Kansas State University. "However, a steam trap that does not operate properly will cost the user both money and time."

As steam condenses, it releases heat. A leaking trap allows the steam to seep into the return system. The steam condenses in the return piping instead of the heating equipment, so that energy is essentially lost.

"Over time even a small leak can be a large financial drain," Meyer said.

Meyer said there are several methods for checking steam trap operation, but the best is to use a test valve.

"Opening a test valve on the trap and closing a shutoff valve located downstream, you should observe a flow of condensate--continuous from float and thermostatic traps, intermittent from inverted bucket traps," he said.

"If condensate does not appear, or if steam blows out continuously, there is a problem, and a detailed examination is in order," Meyer said. "If such is the case in your system, call the manufacturer. He will provide instructions for properly installing the test valve."

"Taking a few minutes to check the trap for proper operation, plus handling repairs before the system is beyond repair will assure operation at peak efficiency."

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4. What are low-emissivity windows, and what are their advantages?

"Low-emissivity windows have a special coating on the glass that reduces radiant heat transfer, thereby increasing the window's insulating value," said Doug Walter, president of Kansas Building Science Institute, Manhattan.

Emissivity refers to a surface's ability to radiate energy and is expressed as a value between zero and one. A perfect radiator has an emissivity of one.

The emissivity of clear glass is about 0.85. A low-emissivity coating can reduce that to about 0.15, boosting the R-value of a double-glazed window from two to almost three.

"This has the same R-value as triple glazing, but without the increase in weight or size and at much less expense," Walter said.

Low-emissivity coatings also reduce solar transmission. This is an advantage in summer, but a disadvantage for south-facing windows in winter.

"The year-round benefits of low-emissivity windows outweigh any loss of winter solar heat gain and thus are appropriate for any window orientation," Walter said.

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5. I have heard that radon levels may be high in private well water supplies. Can I safely drink the water?

"Yes," said Bruce Snead, extension specialist in residential energy at Kansas State University. "The risk associated with drinking water that contains radon is very, very small."

"Radon is a significant health risk only when it is breathed into the lungs in its gaseous form," Snead said. "Radon in water can become airborne when it outgases, increasing the radon level in the air, but while it is in the water the level of potential harm is very limited.

"If there is no measured problem with airborne radon in a home, there is generally no need to test for radon in household water," Snead said. "By far the greatest source of radon in most homes is from underlying soil."

Radon can dissolve into passing ground water. How much radon enters the water depends on the uranium level in the soil and the flow rate of the water. High concentrations of radon in ground water have been found in a few areas of the northeastern and western United Stated.

"Radon is released from water when the water is exposed to the air," Snead said. "The household water supply is rarely a significant contributor to indoor radon."

Usually only 2 to 5 percent of the radon found in a home comes from household water.

"When water is supplied by a municipal system, radon is released while the water is being treated," Snead said. "When water is held in storage, radon is transformed into other substances by radioactive decay."

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6. What can you tell me about the new front-loading washing machines?

"Front-loaders have been in laundromats and in Europe for years," said Gene Meyer, extension mechanical engineer at Kansas State University. "Their new appeal here in the United States is a result of their reduced use of water and energy."

A study done by the Department of Energy (DOE) in Bern, Kan., showed water consumption fell from 41.5 to 25.8 gallons per load.

"The study was done in Bern in part because it had a chronic water shortage and DOE wanted to determine if switching to a new style of washer would help alleviate the water shortage problem," Meyer said. "Monthly water usage for the town dropped 50,000 gallons per month."

In addition, energy used to heat the water is also reduced. If water is heated with electricity, annual savings would be in the range of $15 to $25 per year.

"Front-loading washers are more expensive," Meyer said. "The three U.S.-manufactured washers start at about $700, about $200 more than the better top-loading washers."

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7. I am building a new home and an insulation specialist advised me to install a vapor barrier. What is a vapor barrier and how can I install it?

"A vapor barrier is an impermeable material, typically plastic or asphalt paper, attached to insulation," said Richard Nelson, extension specialist at Kansas State University.

"The purpose of a vapor barrier is to prevent moisture from passing through the insulation and condensing on the cold outer surfaces," Nelson said. "A vapor barrier has two main functions: keeping moisture inside your home, and preventing it from condensing in the insulation," said Nelson.

"Since you are constructing a new home, apply a sheet of polyethylene film to the inside structure before installing the drywall," Nelson said. "Always apply the vapor barrier on the warm side of the wall, ceiling or floor."

"If you are going to blow insulation into your attic, lay down the sheet of polyethylene film first," Nelson added.

Everyday household tasks such as washing, cooking and bathing release moisture inside the home. A vapor barrier slows the movement of this moisture from the home's interior to the outside.

The other function of a vapor barrier, protecting the insulation, is useful in winter when indoor air retains more water vapor than the cold outside air. The kraft paper face on the insulation batt should be attached to the studs.

"If vapor seeps into your home's insulation and condenses, the ability to prevent heat loss will decrease," Nelson said. "This is why you apply a vapor barrier to the warm side of a wall, ceiling or floor — to stop the moisture before it reaches the insulation."

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8. We have been advised to add a chemical treatment to our school's hot water heating system. What should we use?

"Chemical treatment is beneficial for any closed loop heating system," said Gene Meyer, extension mechanical engineer at Kansas State University.

Corrosion in the system reduces equipment efficiency by limiting heat transfer and leading to premature failure of the pipes and boiler. Chemicals help control corrosion.

"They do not replace normal system maintenance, but can reduce the amount of work and extend the life of the system," Meyer said.

Most chemical treatment programs include a corrosion inhibitor and something to adjust pH. Proprietary products that do not contain chromate or nitrites are commonly used. Have the treatment specialist help you monitor the water for proper treatment.

"A safe rule of thumb is to check your system semi-annually," Meyer said.

"You can do this by following test kit instructions that should be provided by your full service water treatment specialist.

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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.