September 3, 1995
My refrigerator runs most of the time. Do I need a new one?
"During the summer heat, your refrigerator may need to run most of the time to maintain the proper interior temperature," said Gene Meyer. extension specialist in small business energy at Kansas State University.
There are, however, some things you can do to help reduce your refrigerator’s running time and lower your operating costs.
"Take out everything you need from the refrigerator at once instead of opening and closing the door several times for one meal," Meyer said.
I'm planning to orient the front of my earth-sheltered home to the south. Because my building site is on the south side of the road, the back of my house will face the road. How can I make it look attractive?
"If the roof is covered with earth, landscaping is the key to creating an attractive image from the roads," said Doug Walter, extension specialist in residential energy at Kansas State University.
A professional, long-term landscaping plan is probably well worth the cost and effort. In addition to enhancing the appearance of the home, the landscaping also will help stabilize the soil, control run-off, deflect winds and catch snow.
"If the house has a conventional roof, landscaping will play a key role, but architectural elements also can be used to create an attractive rear facade," Walter said.
You might want to consider a steep roof to give the appearance of a more massive structure. Skylights, dormer windows, and clerestories also can be used to give visual interest to the roof, but use these sparingly because north-facing glass is not energy-efficient.
"Because the front of the house will face away from the road, the driveway becomes the entry to your home," Walter said. "So it should be clearly marked and attractively landscaped."
September 10, 1995
What should I consider before purchasing a whole house fan?
"First, you should determine the size of fan you need for your house," said Doug Walter, extension specialist in residential energy at Kansas State University. "To do this, compute the volume of your house by multiplying the total floor area by the ceiling height."
For a whole house fan to cool effectively, it must create 40 air changes an hour. The fan you select should be able to move two thirds of your house volume in one minute to provide 40 air changes per hour. If you have a large house with several floors, you might want to consider sizing the fan for just one floor.
"Second, determine where you will install the fan," Walter said. "Whole-house fans most often are mounted horizontally in the ceiling between the attic and the top floor of the house. Some models, however, can be mounted vertically in a side wall."
If you plan to install the fan yourself but don’t want to cut through ceiling joists, consider a model that fits between standard ceiling joists or mounts on top of them. Although some carpentry is involved, ceiling joists don't have to be cut to install one of these models.
"If the model you choose discharges through the attic, be sure to allow enough vent area for the air to escape without building up pressure in the attic," Walter said.
One square foot of open vent area for every 750 cfm (cubic feet per minute) of the fan's rated air moving capacity is recommended. For example, a fan rated at 4,500 cfm needs six square feet of open vent area. Whole house fans are available in direct drive and belt drive models.
Direct drive models have the fan mounted directly on the motor shaft. They are usually quieter and require less maintenance than belt drive models.
"Belt drive models often require less energy per cfm of capacity than do direct drive models because the fan motor can be matched more closely to the optimum fan speed," Walter said.
Belt drive models are also usually available in larger sizes.
"When you install your whole house fan, you also may want to consider a variable speed motor controller and a timer," Walter said.
The variable speed controller allows you to operate the fan at different speeds. The timer lets you turn the fan on in the evening and have it shut off automatically during the night after you have gone to sleep.
Do insulated garage doors save energy?
Yes, if the garage doors are used in a space that is either being heated or cooled.
"Conventional garage doors are typically made of a single ply of either wood or fiberglass material," said Dennis Matteson, extension specialist in small business energy at Kansas State University.
This material is not a good insulator, which means it allows heat to be lost in the winter and gained in the summer.
By either replacing the door with an insulated garage door or by installing insulation panels on the interior of the door, you can reduce your heating and cooling load greatly.
"Also, if the door does not seal well, apply a good flexible seal around its sides, bottom and top to reduce the heating and cooling load even more," Matteson said.
September 17, 1995
What insulation has the best R-value?
"The application of the insulation often determines what types of insulation you should use," said Gene Meyer, extension mechanical engineer at Kansas State University. "Because I don't know what your intended use is, here is a list of common insulating products and their R-values."
Batts and loose fill
I am considering building an earth-sheltered home, primarily to avoid the need for air conditioning. Why do so many earth-sheltered homes have air conditioning?
“Although an earth-sheltered home requires much less air conditioning than a conventional home, a small air conditioner is necessary to control humidity and internal heat gain,” said Doug Walter, extension specialist in residential energy at Kansas State University.
Appliances, lights and household activities such as cooking and baking generate heat and moisture that must be removed.
Exposed walls are also a source of heat gain because they often contain large amounts of glass. Even well-shaded windows admit heat by conduction, infiltration and indirect radiation.
“As soil temperatures rise during the summer, the cooling effect of the soil diminishes,” Walter said. “By late summer, little or no heat will be lost (transferred?) to the soil.”
As a rule of thumb, an earth-sheltered home will require 12 to 15 Btu of cooling capacity per square foot of floor area. If you plan to install central air conditioning, you should be aware that the smallest capacity air conditioner available is about 18,000 Btu per hour.
September 24, 1995
What is radon and is it associated with energy-efficient homes?
“Radon, a naturally occurring radioactive gas, is present in all soils in varying concentrations,” said Bruce Snead, extension specialist in residential energy at Kansas State University.
Exposure to elevated radon concentrations over long periods of time increases your potential for developing lung cancer. Lung cancer is the only health effect of radon exposure.
Radon enters a home through cracks and openings in the foundation and is drawn in by the suction created by various driving forces affecting air pressure differences. All types of homes can have elevated radon concentrations.
Energy-efficient homes may be built with tighter foundations to resist radon entry, but their air change rate or ventilation rate may be low, which can allow radon to build to levels above the EPA guideline of 4 picocuries per liter.
Drafty older homes may have higher air change rates but foundations which are leaky and allow a greater amount of radon in, also resulting in radon levels above the EPA guideline.
There are simple techniques builders can use to make a new home radon resistant and energy-efficient. Older homes that have high radon levels can almost always be fixed.
The only way to know if a house has high radon levels is to conduct a test. Contact your county extension office or health department to see if they have low cost test kits on hand and information on radon and your home.
What is an energy management system?
“An energy management system (EMS) is a device or combination of devices used to control the energy usage in a building or facility,” said Dennis Matteson, extension specialist in small business energy at Kansas State University.
Most larger electrical users are billed according to demand, the highest electrical usage for a specified time, and the consumption, that is, the amount of electricity used. Gas cost is usually based only on the amount used.
“Effective energy management will allow equipment to operate only long enough to accomplish its task—thus reducing the amount of electricity or gas used,” Matteson said.
If there is a demand charge, the EMS should schedule the equipment to minimize demand penalties. “Energy management systems can be operated effectively without loss of comfort and productivity only after a thorough analysis of the equipment operations,” Matteson said.