Will covering the open refrigeration and freezer cases in my store help reduce the cost of cooling them?
Night covers for both refrigeration and freezer cases are a good idea to help keep the cold air inside the case.
"These covers can be as simple as a heavy piece of cardboard or a sheet of canvas draped over the top or front of a case at night," said Gene Meyer, extension specialist in small business energy at Kansas State University.
Cold air leaking from a refrigeration or freezer case is a major energy waster. During the winter, the cold air escaping from the case also requires additional heating for your store.
Most stores have moved away from open freezer and medium temperature cases. Open cases are still common for meat, some dairy items, and vegetable cases. Where open cases are used, proper stocking is critical to prevent cold air from spilling from the case.
How can I reduce the cost of lighting in my home?
"The greatest savings in residential lighting result form turning off unneeded lights," said Richard B. Hayter, director of Engineering Extension at Kansas State University. "Dimmers also save energy when used with incandescent bulbs but should not be used with most fluorescent fixtures."
If low light levels are consistently needed in a room, reduce lamp wattage rather than use dimmers.
Fluorescent lamps are many times more efficient than incandescent lamps, Hayter said. In addition, recent advances in fluorescent technology has allowed greater flexibility in lamp size and shape. Compact fluorescent lamps come with ballasts and simply screw into existing incandescent fixtures.
If you use conventional four- or eight-foot fluorescent lamps, you should consider changing lamps and ballasts to use the more efficient T-8 style lamp and electronic ballasts.
"While the cost to buy the efficient products will be greater, the savings more than pay for the additional costs over the life of the product," Hayter said.
What products are available for waterproofing earth-sheltered homes?
"Protecting an earth-sheltered home from water involves selecting a good site with no inherent drainage problems, providing adequate drainage away from the roof, walls, and foundation, and selecting and applying a suitable waterproofing agent," said Bruce Snead, extension specialist in residential energy at Kansas State University.
Waterproofing materials used below grade must be just that---waterproof, not just damp-proof or vapor-proof. The material should be able to expand and contract without cracking, providing a continuous cover for the entire surface or structure. It should be unaffected by any type of soil and adhere to the roof and wall materials used in underground construction.
"Two generic materials are being widely used to waterproof underground homes: elastomers, and rubberized asphalt," Snead said.
Elastomers and polymers used for waterproofing are sheet and liquid forms of synthetic rubber. Sheets (up to 50 feet) may be glued to the building and sealed at overlapping joints. Spray-on types are easily applied and may serve as a bonding agent for exterior insulation. Elastomers are best on large unbroken surfaces and must be carefully applied under good weather conditioners.
Rubberized asphalt is another waterproofing material. Unlike regular asphalt, which degrades in the presence of water, rubberized asphalt works fairly well beneath the surface. Available in three and four-foot rolls, rubberized asphalt should be used on surfaces which have some slope because it is not intended to perform under continuous water pressure. Seams are either self-sealing or must be glued.
"Selecting a waterproofing system for your earth-sheltered home requires thorough research and careful evaluation of your site and building characteristics to determine which material is most suitable for each application," Snead said.
If I insulate only part of my attic, will it cause the heat loss from the rest of it to increase next winter?
No.
"Heat loss from any part of a house can be compared to water leaking out of a bucket that has several holes in the bottom," said Doug Walter, extension specialist in residential energy at Kansas State University. "By plugging up some of the holes, you don't cause the others to leak faster."
"However, a complete and skillful insulation job can reduce air leakage through your house by sealing off hidden, inter-connected air passageways," Walter said. "A partial job may have very little effect on air leakage."
What's the status of photovoltaic technology?
"Significant advances have been made in the field of photovoltaics, or generating electricity from sunlight," said Richard B. Hayter, director of Kansas State University's Engineering Extension.
Laboratories the world over are developing solar cells with increased efficiency and lower production costs. Photovoltaic technology is now economical enough to use in remote sites where electrical transmission lines would be extremely costly to install, Hayter said. On a small scale they are used for electric fence chargers, livestock watering, traffic counters, tower beacons, warning sirens and remote radio transmitters. Large-scale uses range from supplying the electrical needs of homes to a utility generating station.
"The future of photovoltaics looks very bright. As production costs continue to drop and efficiencies increase, solar cells will find more and more applications in everyday life," Hayter said.
In a previous column you suggested closing off the registers in unused rooms to conserve energy. Is it possible to close off too many?
"Yes. Closing too many registers may cause your furnace to overheat," said Gene Meyer, Kansas State University extension specialist in small business energy. "Furnaces
need the cooling action of room air flowing through them to cool the unit. Closing off too many registers will restrict air flow and reduce that cooling action."
Meyer added that furnaces are usually equipped with a safety device that shuts off the main gas valve to prevent furnace overheating.
"But it is not a good idea to use the safety switch as a controller," he warned. According to Meyer, no more than two out of 10 registers should be closed at one time.
"After you have closed them, watch the furnace go through a long heating period," he said. "Turn your thermostat up to 80 degrees and check for anything unusual, such as the gas valve cycling off and on. If things don't seem right, open the registers.
What are the advantages of a two speed or variable speed residential central air conditioner?
"An air conditioner operates most efficiently when the capacity of the unit equals that of the cooling demand placed on it," said Richard B. Hayter, director of Engineering Extension at Kansas State University.
An air conditioner which cools a home under the most severe summer conditions is significantly oversized for most of the cooling season.
So, some manufacturers now offer a multistage central air conditioning unit which basically has two compressor speeds or variable speed compressor. This allows the unit to operate at high efficiency under both mild and severe conditions.
Hayter warned homeowners not to confuse window air conditioners that have "high cool" and "low cool" control positions with a central air conditioning unit which has multiple capacities. Window air conditioners typically have a two speed fan and not a multispeed compressor.
What window material is the best insulator? Is acrylic plastic better than glass?
"No. Window pane material has little to do with the insulating value of a window, said Tom Logan, energy specialist at Engineering Extension, Kansas State University. "A typical single-pane window has an R-value of about 1. Several different contributions to that R-value must be considered."
The largest portion of the insulating ability comes from the natural heat flow resistance of the air layers on the two sides of the window pane, Logan said. The air washes against the pane and is slowed. This slower moving air layer provides most of the insulation value.
"The window pane material provides some insulating value, but not much," Logan said. "This is because the glazing material is, of necessity, very thin."
For example, a pane of glass one-eighth of an inch thick has an R-value of only 0.013, about one-seventh of the window's of the window's total insulating value, according to Logan.
"Multiple panes in a window will increase the window's insulating value because they create more layers of air," Logan said. "A double-pane window has an R-value of about 2 and a triple-pane window has an R-value of about 3, regardless of the transparent material used to make the panes."
The insulating value of windows can also be increased by applying a transparent low-emissivity coating to the glazing material, which reduces heat flow by radiation. These windows are often referred to as "low-E" windows. A low-E double-pane window has an R-value of about 3.