Although the gas dryer is more economical in the long term, it has higher initial costs.
The initial cost for a gas dryer is usually $35 to $50 more than for a comparable electric dryer.
Installation costs probably will be higher due to the gas line connection.
These higher first costs, however, will be recovered in lower operating costs associated with the gas dryer.
"How quickly the higher initial costs for a gas unit will be recovered in lower operating costs depends on the amount of dryer use," Snead said.
Under typical conditions, the gas dryer will pay for itself in savings within one to two years, he said.
My business requires cooling earlier in the spring and later in the fall than my home. Is there a way to use cool outside air for cooling my business instead of air conditioning during these mild periods?
"Yes, the use of outside air for cooling is referred to as 'economizer cooling,'" said Gene Meyer, extension mechanical engineer in small business energy at Kansas State University.
Standard control packages are available that determine if the outside air is cool enough to perform the necessary cooling. They also automatically sequence dampers to the proper position to provide this free cooling.
In businesses where the cooling season is extended into early spring and late fall, or throughout the year, economizer control strategies can significantly decrease your electrical costs.
March 10, 1996
What is an electric air cleaner?
"An electronic air cleaner is a device that uses an electrostatic field to draw airborne dust and particles to a filter media or plate," said Richard B. Hayter, director of Engineering Extension at Kansas State University.
Electrostatic precipitation has been used extensively in industrial and commercial processes for several years. More recently, this device is used in homes for air cleaning; particularly by those who may be allergic to airborne contaminants, such as pollen or tobacco smoke.
The device is typically installed on the return air duct leading to the forced air furnace. The particles are charged as they pass through the device and are electrostatically attracted to the filter.
"The filter media or plate must be cleaned regularly for the device to operate properly," Hayter said.
As with any air cleaning device, air flow through the furnace or air conditioner can be restricted if the filter is clogged.
"Many cleaners are constructed so that the elements can be removed and cleaned in an automatic dishwasher," Hayter said. "You should pay close attention, however, to the manufacturer's recommendation."
Although electronic air cleaners are designed with safety devices to prevent electrical shock, you should disengage the circuit breaker to the filter before working on the cleaner.
What can I do to reduce the energy used to dry clothes?
"Several cost cutting measures can be used to save energy when drying clothes," said Bruce Snead, extension specialist in residential energy at Kansas State University.
March 17, 1996
The ducts that deliver air to individual registers in my home heating system consist of four inch diameter pipe. I've heard these are not adequate for air conditioning. If they're adequate for heating, why won't they work for cooling?
"Heating generally requires a smaller volume of air for adequate delivery than air conditioning does," said Doug Walter, extension specialist in residential energy at Kansas State University.
A furnace can deliver air 60 to 70 degrees Fahrenheit above room temperature, while an air conditioner delivers air that is only 15 to 20 degrees Fahrenheit below room temperature.
"Even though most homes have a greater hourly heating requirement than cooling requirement, the air conditioner usually requires more total air flow," Walter said.
Four-inch diameter ducts are a problem because their air carrying capacity is very limited. At a constant air velocity, a four inch duct can carry only 45 percent of the air volume of a six inch duct, which is used in most newer systems.
A greater limitation, however, is the increased resistance to air flow provided by the smaller duct. At constant air volume, a four inch diameter duct has more than 100 percent greater resistance to air flow than a six inch duct.
"You can make a rough determination of your system's ability to accommodate air conditioning," Walter said. "Begin by obtaining an estimate of the size of the air conditioner you need in tons from an air conditioning contractor."
One ton equals 12,000 Btu per hour.
Multiply each ton of capacity by 450 to get an estimate of the total air flow required by the air conditioner in cubic feet per minute (cfm). Then, divide the required cfm by the total number of individual four inch ducts in your system.
"The resulting number ideally should be 50 or less, and in no case more than 75," Walter said. "If you get a higher number, your system probably will give poor cooling performance."
You can enhance performance by adding more air ducts or replacing the existing ducts with larger ones. Another option is to replace the furnace blower with a special blower designed to operate at high static pressures, he said.
March 24, 1996
What is an electrical interlock?
An interlock is a device that uses one electrical load to control the operating time of another electrical load.
The device is effective in reducing electrical costs only if demand is used to calculate the your electrical bill," said Dennis Matteson, extension specialist mechanical engineer at Kansas State University.
Your demand is determined by your largest average energy consumption over a 15 or 30 minute interval. When several large loads are operating at the same time, the combined demand is registered.
"The interlock does not reduce the amount of electricity used but controls the operating time for each unit," Matteson said.
"Interlocks provide a quick payback if you are on a demand rate schedule," Matteson said.
An example use for an interlock would be having your electric dryer turn off your electric water heater.
"The control signal from the dryer would delay the water heater from operating until the drying cycle finishes," Matteson said.
Unless you had a large demand for hot water occurred during the dryer operation, you would not notice the interlock.
Assuming each unit has a three-kilowatt hour load, the demand without the interlock register would be six. With the interlock, however, the demand for these two units could not exceed three.
"If the demand charge is $6 a kilowatt hour, the interlock would save $18 each month," Matteson said.
If the installation cost of the interlock was $90 the interlock would pay for itself in approximately five months, then save over $200 annually.
Interlocks are available at most electrical supply stores. The newer models can be installed in the breaker box and require less installation time.
March 31, 1996
I'm building a new house and want to make it as energy efficient as possible. How significant are the colors I choose for the roof and walls?
"You can achieve best all around performance and durability with light colors," said Doug Walter, extension specialist in residential energy at Kansas State University.
Building surface colors have little effect on heat loss in winter, particularly through well insulated ceilings and walls.
Dark surface colors can, however, significantly affect heat gain in summer.
The total heat gain through a ceiling with R 38 insulation, even with a well ventilated attic, will be about 20 percent higher if the roof is dark colored rather than light. With R l9 attic insulation, heat gain will be 35 percent higher.
"Dark roofs also tend to age faster, due to greater expansion and contraction and thermal degradation," Walter said.
Wall color is not so significant to heat gain as roof color unless there is a large exposure on the west wall. North and south walls are shaded from intense exposure to solar radiation in the summer, while east walls receive intense exposure during the coolest hours of the day.
I am building a new house. Should I use a radiant barrier in the attic instead of conventional insulation?
No.
"In Kansas's winter climate, conventional types of insulation are necessary to cut heat loss from the interior of the house through the ceiling," said Bruce Snead, extension specialist in residential energy at Kansas State University.
Insulation properly installed and attention to air sealing will reduce air leakage through the ceiling as well.
A radiant barrier provides the greatest savings in the summer by reducing radiant heat transfer from a hot roof to the attic floor.
Its effectiveness in winter does not match that of conventional insulation.
With significant heating and cooling loads in the Kansas climate, there may be justification for using a radiant barrier in addition to conventional insulation.
In homes with full exposure to the sun, extensive reliance on air conditioning, and above average electricity rates, a reasonably priced radiant barrier is likely to be a cost effective investment.
"A new home is a good candidate for a radiant barrier," Snead said, "because it is easy to install during construction, and because the roof is likely to be fully exposed to the sun for many years until trees grow large enough to shade the roof."