Good argument for a programmable thermostat

Q: Whenever we come home to an empty house, my husband always sets the thermostat way high in winter. He says it warms the house quicker. We try to save money by turning it down when the house is empty, but I wonder if we’re losing any savings when he sets it so high for a few hours to warm us up. Is he offsetting our savings this way?

A: This is a question I get often, and the right answer is actually “yes and no.”

On the one hand, setting the thermostat higher than your normal settings won’t heat up the house any quicker. You’re much better off picking a desired setting (such as 68 degrees) and setting it for that. When the house reaches the set temperature, the heater will not bring it any higher.

However, just setting it higher than what you want it to be won’t cost you anything extra unless you let it get above your desired temperature. Remember to adjust it when you’re comfortable and don’t let it keep on heating beyond what you really want.

The problem comes up on the other hand. People often make these radical adjustments, then forget to bring the setting back to normal. Not only will the house not heat any quicker this way, but if you forget, it’s liable to get way above the desired setting before you realize how hot it has gotten and you turn it back down.

When you realize that when you turn your setting for heat above the optimal point in winter (68 is usually recommended) or below it in summer (78 is best from an energy-savings standpoint), you are increasing your heating or cooling use by as much as 10 percent for every degree beyond the recommended setting.

This is one of the strongest arguments for a programmable thermostat that will adjust the settings to your lifestyle but won’t forget to turn them back to the desired levels. Most of these automatic thermostats have multiple settings that you adjust for when you’re at work or during the weekends or other times, and the thermostat makes the changes — and doesn’t forget to turn it back to the desired temperatures at the right times.

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Q: We’re hoping to buy a large lot soon and eventually build a retirement home there. Any tips for picking a good site that will let us use many of the passive solar principles you have written about?

A: Your question shows that you’re already on the road to having a good passive home because some factors of the site itself — including its location and orientation — are critical in creating a comfortable and energy-efficient home.

By definition, a passive solar home is one that takes maximum advantage of the sun to provide heat in winter by utilizing the sun’s warmth and also give cooling comfort in hot weather by blocking the unwanted warmth. It is both the design and features of the home that make the difference here as they work together to make the passive principles work best.

These strategies include the size and placement of windows, roof overhangs, color of the walls and roof and landscaping, as well as the orientation of the home which includes putting the largest windows and other passive features facing as true south as possible.

Here are just a few areas to think about when looking at a site:

•Try to find a neighborhood where streets have been laid out to run east and west. Most homes on such streets will be built with the front of the house facing the street, keeping the home’s long axis east to west (thus minimizing windows facing directly east and west).

•Lots that are deep from north to south will give you the most control over the areas of solar access.

•You’ll get even more solar access on flat or south-sloping lots. North-sloping lots give off longer shadows.

•If your house plan makes maximum use of the sun in the front, then look for a lot on the north side of the street. If your big windows and other solar access areas are in back of the house, then try to find a lot on the south side of the street. One extra tip here: solar access on the front of a house can be especially valuable because the street itself will serve as a buffer against any future building that could block that solar access you’re trying to get.