60 degrees efficient, largely intolerable

Q What is the most efficient home thermostat setting -- 60 or 65 degrees? I realize it would take more energy to reach 65 degrees, but does it cost much more to maintain the temperature at 65 vs. 60 degrees? I find that when turning the thermostat down and then up, the furniture and such absorb the cold and emit the cold into the air.

A The temperature that's most efficient, that uses the least amount of energy, is 60 degrees, said Phil Smith, energy specialist at the Minnesota Office of Energy Security.

If you kept the house at 60 instead of 65 degrees for a whole winter, you would see a 10 to 15 percent reduction in your utility bills, he said. But not many people could tolerate that, he added. Indeed, young children, seniors and those with compromised health often cannot tolerate 60 degrees without major health effects, including hypothermia.

Smith explains how turning down the thermostat saves energy and money as follows:

Heat moves to cold, and the quantity that moves is determined by two factors: Thermal resistance of the building envelope (walls, windows, doors, ceilings), and the temperature difference between the warmer and cooler spaces. Change one or the other of these factors, and you change the quantity of heat flowing. Thus, lowering the thermostat cools the home and reduces the temperature difference between the indoors and outdoors. That slows heat flow, which translates into less demand on the furnace or boiler, less gas or electricity used, and that's money saved.

Smith said that home furnishings do serve as a minor heat storage system, but it's not much in the big picture of how your house works, Smith said. More often it's the perception of temperature that's in play.

Depending on the fabric or surface, some items feel cooler because more warmth is moving from your body. A good example can be found in bathroom tile and towels. Both are at the same temperature, but when touched the tile feels colder than the towel.

To save energy and money, Smith recommends setting back your thermostat whenever you can.

More on moldy odors in washers In response to last week's column on moldy odors in washing machines, Joann Parker wrote:

"We wipe out the washer and the gasket, and we always leave the washer door open between washes to allow it to dry out. We also remove the soap/bleach dispenser, wipe it out, and wipe out the area in the washer where it is housed. We also leave that dispenser out of the washer and set it up to thoroughly dry in the laundry tub. That allows the area where the dispenser is housed to dry out thoroughly as well. No problems."

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies.