Micro heaters cut 87% off my electric heat bill

> In defense of Californians, most of us rarely, if ever, turn on a heater and most homes here don't have AC

Then why on earth was I freezing my balls off in Menlo Park this November? The weeks before we realised our house even had heating were miserable. And even afterwards, as soon as the heaters weren't blowing hot air, or you were more than 3ft away, you were instantly cold and miserable.

Energy is abundant, there is no need to shiver in the cold. Solar forced warm air is inexpensive, simple technology that is very underutilized.

Solar photovoltaics get all the attention, but solar warm air/water is less expensive and simple to manufacture.

http://sunmatesolarpanels.com/content/view/2/31/

In moscow, they do this in what is (nominally) summer for almost 2 weeks. I thought the water would be chilly, but if I took brisk showers I'd be ok. The first time I tried I nearly gave myself hypothermia -- no exaggeration, I was under a blanket unable to stop shaking for 10 minutes -- and figured out why I saw kettles in people's bathrooms when I was a guest in their apartments. Thank god for the gym which was in a different area of the city.

OK, Paul Wheaton simply doesn't know what he's talking about:

"I think that this does produce some savings, but not as much as you might think. If you set your thermostat to a constant 70, the heater works a little at a time throughout the day. If you drop it to 50 at night or in the middle of the day, the heater stops working, but then when the time comes to warm the house again, the heater has to work at full power for a long time to get the temp back up - thus losing a lot of your savings."

WRONG WRONG WRONG WRONG WRONG WRONG WRONG WRONG WRONG

Heat losses are driven by two factors:

1. The temperature differential between the hot and cold sides.

2. The thermal conductivity (or exchange) between the hot and cold sides.

That's straight out of Newton's Law of Cooling / Fourier's Law:

http://en.wikipedia.org/wiki/Convective_heat_transfer#Newton...

If you're running heat constantly, you're maintaining a constant flow of heat from your interior to the exterior. That is, you're maintaining a high heat exchange rate to the exterior, and you're constantly wasting a large portion of heat.

If you're heating only while you need a warm interior, then as the interior temperature falls, the energy flux to the exterior decreases. You're no longer pumping heat into the external environment.

Yes, you'll run your furnace/heating system continuously for a while in raising the interior temperature, but that is largely adding heat to the interior space, not to the exterior.

The net is expending less energy.

Your most efficient strategy is to turn interior heat down to the minimum essential level (ultimately: enough to keep pipes from freezing), or the minimum level the thermostat allows (often ~50F in the US). My own practice is generally to turn any heating system off entirely at night.

From a moisture management perspective, you also win as cold air has a lower absolute humidity, that is, the quantity of water it can hold is lower. Heating cold humid air reduces the relative humidity, allowing walls and surfaces to dry out.

The overnight heat loss is also a very clear sign that Paul Wheaton is dealing with an exceptionally poorly insulated structure. And a very poor grasp of thermodynamics.

The same principle holds for AC as well, though here you want to increase the temperature setting at which the AC comes on, or disable AC entirely while you're out of the home.

A better way of thinking of this is to minimize the energy input (heating or cooling) when it's not needed.

See:

http://www.uswitch.com/energy-saving/guides/heating-on-all-t...

http://www.straightdope.com/columns/read/2970/does-turning-d...

http://energy.gov/energysaver/articles/thermostats

Manufacturing and shipping costs of incandescents are very small relative to their energy utilization, as reflected in costs.

Your point about fixtures and heat losses through ceilings are actually well-taken. Recessed "can" lighting is actually a huge pathway for heat loss two ways:

1. The radiant heat from bulbs which is transferred into the ceiling and attic spaces, rather than the living space.

2. Other heat flow losses, including often very significant airflow, through the lighting fixtures. Thorsten Chlupp (mentioned elsewhere) includes lighting fixtures among his anti-penetration measures. He also keeps his wiring and plumbing runways along the inner insulates spaces, rather than outside the thermal barrier (with concomitant envelope penetrations).