EcoRenovator - View Single Post - What temperature do you keep your house in the winter?

stevehull · 02-07-14, 12:32 PM

Natethebrown

Set back thermostats work well when there is minimal thermal mass. My last home had some 100 tons of concrete in the thermal envelope and the decay curve was very slow.

I tested this by heating the house to 70F on a night when it was frigid and without wind. Turned off the heat pumps and recorded the exponential curve as the home cooled down that night.

Got only an 8F decay in temp. With this situation, a set back doesn't work well, especially with a geothermal heat pump.

On a customer's recent house analysis, I got almost a 25 F decay in 12 hours. Virtually no thermal mass in the home.

Recording the decay curve is part of my assessment along with blower door tests and evaluating fuel use consumption data. It has shown me where insulation is present and not.

Steve

02-07-14, 12:32 PM	#128
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	Natethebrown Set back thermostats work well when there is minimal thermal mass. My last home had some 100 tons of concrete in the thermal envelope and the decay curve was very slow. I tested this by heating the house to 70F on a night when it was frigid and without wind. Turned off the heat pumps and recorded the exponential curve as the home cooled down that night. Got only an 8F decay in temp. With this situation, a set back doesn't work well, especially with a geothermal heat pump. On a customer's recent house analysis, I got almost a 25 F decay in 12 hours. Virtually no thermal mass in the home. Recording the decay curve is part of my assessment along with blower door tests and evaluating fuel use consumption data. It has shown me where insulation is present and not. Steve __________________ consulting on geothermal heating/cooling & rational energy use since 1990