Comments lilylily has made

Radiant slab or high thermal mass exceptions

Umbra is right that setting the thermostat back will result in energy savings for most homes. The less the inside/outside temperature differential, the less the heating costs. But for high mass homes, especially those with radiant floor concrete slabs, it could cost some people more money to allow their temperatures to fluctuate. They might be heating them when they're not home by overshooting their needs.

Take the example of someone who awakes and goes to work for nine hours, leaving the house empty. They only need full warmth for a short time in the morning (and when they return in the evening) of workdays.  With a low mass house, they'd use less power to get air temperature up to 68 degrees briefly in the AM then let it relax while they're gone. Someone with the thermal lag of a high mass home would take longer to heat it for a short morning use.

I've designed energy-efficient homes for 30 years, and work with a leading energy researcher/engineer who conducts workshops for architects and builders after doing scientific thermal studies on literally thousands of homes for an energy company. We've designed net-zero-energy homes that actually work well. He uses radiant slabs and super-insulation as his main features to save energy. With that solution, a setback thermostat is unnecessary and counterproductive. These are rare now, but with pending climate change regulations, will soon become popular if not nearly mandatory in some areas of the country.

For the rest of you, don't heat when you don't need heat. And stop leaks, add insulation, build smaller, rely more on radiant heating, wear a sweater, and exercise more to keep your metabolism higher so you're naturally warmer inside.On Umbra on turning down the heat posted 11 months, 4 weeks ago 21 Responses