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stevehull · 02-21-13, 03:56 PM

I agree with Daox,

All resistance heaters have a COP of 1.00 by definition. This would include any device that asserts it is an infrared high efficiency heater ("Amish Heaters"). One kW = 3415 BTU. And if each kW costs ten cents ($0.10 - about the national average, $1 gets you ~34,000 BTU.

Sadly, some assert that resistant heat is 100% efficient compared to a high efficiency gas furnace ~94% efficiency. What they do NOT tell you is the energy cost of the fuel.

The above calculation, which gives you the cost of heat per $ of fuel is the best way I know of comparing apples to apples.

If a heat pump has a COP (coefficient of performance) of 4, then for each $ of electricity cost (@$0.10) would be 136,000 BTU/$. This is why heat pumps work so well.

Incandescent light bulbs are essentially resistance heaters as ~ 90%+ of the electrical energy goes to create heat.

By contrast, LED bulbs have the opposite (higher) efficiency with very little heat and lots of light (~90%).

Steve

02-21-13, 03:56 PM	#3
stevehull Steve Hull Join Date: Dec 2012 Location: hilly, tree covered Arcadia, OK USA Posts: 826 Thanks: 241 Thanked 165 Times in 123 Posts	I agree with Daox, All resistance heaters have a COP of 1.00 by definition. This would include any device that asserts it is an infrared high efficiency heater ("Amish Heaters"). One kW = 3415 BTU. And if each kW costs ten cents ($0.10 - about the national average, $1 gets you ~34,000 BTU. Sadly, some assert that resistant heat is 100% efficient compared to a high efficiency gas furnace ~94% efficiency. What they do NOT tell you is the energy cost of the fuel. The above calculation, which gives you the cost of heat per $ of fuel is the best way I know of comparing apples to apples. If a heat pump has a COP (coefficient of performance) of 4, then for each $ of electricity cost (@$0.10) would be 136,000 BTU/$. This is why heat pumps work so well. Incandescent light bulbs are essentially resistance heaters as ~ 90%+ of the electrical energy goes to create heat. By contrast, LED bulbs have the opposite (higher) efficiency with very little heat and lots of light (~90%). Steve __________________ consulting on geothermal heating/cooling & rational energy use since 1990