Ask Energenie

February 1999

Table of Contents

1. Are there special regulations for water source heat pump wells?
2. I'm building a house with a walkout basement. Should the exposed basement wall be concrete like the rest of the basement, or can it be of frame construction?
3. How can I insulate my floored attic?
4. If I buy a ceiling fan, how much can I expect to save on my heating and air conditioning costs?
5. Are test kits for measuring radon gas accurate?
6. I have a new house that seems to be very tightly constructed. I've heard that operating combustion appliances, like the furnace and water heater, can be unsafe in very tight homes. What can I do to make sure mine operate safely?
7. I’ve been thinking about getting a carbon monoxide alarm for my home since they’re becoming so inexpensive, but I hear that I need to be careful in picking one. Can you point me in the right direction?

| Return to Ask Energenie home page |

1. Are there special regulations for water source heat pump wells?

There are two basic types of water source heat pumps: open loop and closed loop.

"Open loop systems require two wells and must be registered with the Kansas Department of Health and Environment," said Gene Meyer, extension mechanical engineer at Kansas State University.

"The closed loop systems do not require registration, but it is advisable to register them as well," Meyer said.

For open loop systems, one well is a water source and the other is a disposal well. The source well is constructed with the same restrictions as a conventional water well.

"The injection well is typically larger because the ground will absorb water at only 70 percent of the rate that water is taken from the ground," Meyer said.

Closed loop systems are regulated as a test hole. This means the entire hole is plugged with approved grouting material from the bottom of the hole to the bottom of the trench.

"Whenever holes are drilled, it is important to protect the aquifers from contamination," Meyer said. "This is important, particularly when the well penetrates more than one water formation."

For example, if a well passes through both salt water and clean water formations, the two formations must be separated.

"If the formations are under pressure, concrete is recommended as a grouting to separate the two formations," he said. "If the formations are not under pressure, you can use bentonite."

Back to Top

2. I'm building a house with a walkout basement. Should the exposed basement wall be concrete like the rest of the basement, or can it be of frame construction?

"Either wood or concrete is acceptable, but wood is the more economical choice," said Doug Walter, president of Kansas Building Science Institute, Manhattan.

"There is little benefit to building the wall of concrete since you must insulate it anyway," said Walter. "And frame construction allows a less expensive method of insulation than does solid concrete."

Structural requirements for an exposed basement wall are no different than for a two-story house. In contrast to concrete, frame construction allows easier installation of windows, doors and electrical wiring.

"If you build the wall of concrete, be sure to insulate it," advised Walter. "An eight-inch concrete wall has an R-value of only two."

There are several different methods for insulating a concrete wall. One involves framing the inside of the wall and filling the cavities with fiberglass batts or spray-applied cellulose insulation.

Another method involves furring the inside of the wall and then using rigid insulation. Furring is the process of adding one-inch thick strips of wood to the wall. These furring strips provide a space for insulation and a base to nail the interior finish to.

You can also glue rigid insulation to the outside of the wall. If you use this method, be sure to seal the insulated wall with a protective coating, such as a commercially available stucco-like material.

"A concrete wall with one inch of rigid insulation will have an R-value of about seven. Two inches of rigid insulation or three and a half inches of fiberglass batt will raise the R-value to 11," said Walter. "This will provide significant savings over an uninsulated wall with an R-value of only two."

Back to Top

3. How can I insulate my floored attic?

"You may use one of several approaches to insulate your floored attic," said Gene Meyer, extension specialist in small business energy at Kansas State University.

"One of the simplest methods is to drill holes in the flooring and then blow cellulose, mineral wool or fiberglass into the opening."

This method is like blowing insulation into walls. "You can use holes as small as one inch in diameter, but larger holes provide better coverage," Meyer said. "For each joist cavity, drill at least three holes. Holes should be located at both ends of a joist cavity and in the middle."

Another approach involves opening the center section of the floor and then using an insulation blowing tube. This tube is inserted through the floor opening between the ceiling joists (attic floor joists).

"The tube should be long enough to reach the far end of the joist cavity," said Meyer. "Blow insulation through the tube to fill the far end of the cavity. When insulation stops flowing, withdraw the tube about 18 inches." Flow will resume as the tube is withdrawn. Continue the process until the entire cavity is filled.

The blowing tube is typically a two-inch diameter, clear vinyl tube that is attached to the insulation blower's regular tube.

Back to Top

4. If I buy a ceiling fan, how much can I expect to save on my heating and air conditioning costs?

"A ceiling fan saves energy primarily by enhancing comfort in the summer," said Doug Walter, president of Kansas Building Science Institute, Manhattan.

"The amount you save will depend on how much less you use your air conditioner."

A fan creates air movement that can help you feel cooler at higher air temperatures. Research has shown that moving air can compensate for a four-degree increase in air temperature with no perceived loss of comfort.

"This means you can be as comfortable at 82 degrees with a fan moving air across your body as you would be at 78 degrees with no air movement," Walter said.

"For each degree you increase your thermostat setting in the summer, expect to save three to four percent on your cooling bill," Walter said. "So, if you operate a ceiling fan and raise your thermostat setting four degrees, you will save 12 to 16 percent."

Keep in mind that you must keep your thermostat at the higher setting to achieve the expected savings.

"And, in order to be comfortable, you may need a fan in each room of your house," Walter said. He suggested installing a ceiling fan in the most frequently occupied room, such as the family room, and using several portable fans to move between rooms. Any type of fan can enhance comfort in summer, not just a ceiling fan.

In the winter, ceiling fans recirculate warm air from the ceiling to the floor, but the energy savings is not significant, especially in homes with forced-air heat or ceilings lower than 12 feet.

When a ceiling fan operates in winter, the air movement, even when directed upward, often causes discomfort, so you may have to turn up your thermostat.

"Therefore, you just should not operate you ceiling fan in winter," Walter said.

Back to Top

5. Are test kits for measuring radon gas accurate?

"The accuracy of almost all commercially available radon measurement devices has been evaluated in the Environmental Protection Agency's (EPA) Radon Measurement Proficiency Program (RMP)," said Bruce Snead, extension specialist in residential energy at Kansas State University. "This program, which ended in September 1998, let an individual or company compare its equipment or evaluation system to others in the same category."

The testing process used one of two methods. In the first, EPA exposed the test kits to established radon levels and returned them to the company or individual for evaluation.

Sophisticated or more complex equipment required the second method. In this method, the individual or company brought the equipment to an EPA lab to measure the radon in a calibrated chamber.

After the test results were submitted, the EPA compared them to the known sample or lab conditions and established a reasonable degree of accuracy.

"Depending on the class of device, accuracy may be plus or minus 25 percent," Snead said. "Suppose a charcoal canister device was exposed in a home for two days. A reading of four picocuries per liter would indicate that radon levels were between three and five picocuries."

Generally, devices tend to be less accurate at lower radon levels, he said.

Each measurement device has a specific testing purpose for which its accuracy is appropriate. The usual functions are either a short-term screening measurement to identify homes with potential for high radon, or a longer-term measurement to establish average levels and health risks.

Private programs to replace the EPA program have begun and are developing the processes that will substitute for device testing. The best quality assurance you can use is to purchase a test kit that has "EPA listed" written on its package. This means it has met the EPA requirements in the past and assures reasonable accuracy.

As final words of advice, Snead said, "It is important to carefully follow test kit instructions if you want accurate results."

Back to Top

6. I have a new house that seems to be very tightly constructed. I've heard that operating combustion appliances, like the furnace and water heater, can be unsafe in very tight homes. What can I do to make sure mine operate safely?

"A qualified building science professional can conduct a worst-case depressurization test on your home to make sure that your combustion appliances will vent properly to the outside under these worst-case conditions," said Doug Walter, president of Kansas Building Science Institute, Manhattan. "But, to ensure safe operation at all times, combustion appliances in very tight homes should either have sealed combustion air or be isolated from the air inside the house and receive combustion air directly from outside."

Sealed combustion is a design feature of some furnaces and water heaters that allows combustion air to be piped directly to the appliance from outside.

"This feature is quite common on very high-efficiency furnaces," Walter said, "but is still rare on water heaters, unfortunately."

Isolated combustion involves providing an enclosure for the furnace and water heater and piping combustion air into this enclosure from outside.

"Since this directly connects this space with the outside, the enclosure must be insulated as if it were an outside wall," Walter said.

At least one municipality in Kansas has banned the practice of allowing combustion appliances to draw their air for combustion from inside the house in new construction, requiring one of the methods above. Of the two methods, installing sealed combustion appliances is probably the easiest and most effective.

"In any home with combustion appliances, including a wood-burning stove or fireplace, it is probably wise to have a carbon monoxide detector as a safety precaution," Walter said.

Back to Top

7. I’ve been thinking about getting a carbon monoxide alarm for my home since they’re becoming so inexpensive, but I hear that I need to be careful in picking one. Can you point me in the right direction?

Bargain hunters should beware of outdated technology when buying carbon monoxide (CO) alarms

"The Underwriters Laboratories (UL) put into effect a new standard for CO alarms on Oct. 1," said Gene Meyer, extension mechanical engineer at Kansas State University. "As a result, some manufacturers dumped tens of thousands of obsolete alarms on the market at bargain basement prices for the holidays."

Consumers who picked up these alarms did not get the bargains they hoped for, however.

"Alarms made under the old standard use faulty technology," Meyer said. "The old alarms either produce frequent false alarms or no alarm at all."

Consumers have only one positive way to make sure they are getting a CO alarm that meets the new standards.

"You need to look in the product literature to see that it specifies standard "UL 2034-98" and on the UL label on the underside of the alarm for the statement, "UL 2034 Rev October 1, 1998," Meyer said.

As of Dec. 1, 1998, only four manufacturers had CO alarms on the market that were UL-listed under the new standard: First Alert, MTI (Safe-T-Alert), Nighthawk and Patrick Plastic (S-Tech), according to Meyer.

Back to Top| Home |

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.