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One gripe I have about this article is that it tells people to burn gas. Okay... it won't harm your lungs (so much) but will help increase global warming (nice)

One gripe I have about this article is that it tells people to burn gas. Okay... it won't harm your lungs (so much) but will help increase global warming (nice). The contents are fine, though the annalogies are bad (a diesel engine indling in the room? common). Anyway, people will keep burning wood in their homes, just because they like it. Most everybody knows the hazards of smoking and keep smoking anyway (including health professionals)... I guess people banned public smoking because the smell is so ofensive to others, not because they were really worried about their health.

AaronBBrown 14y ago
How go you propose that an individual heat their house if not with gas, propane, oil, or wood? Electric heat, except in the case of perhaps a space heater, is extremely inefficient (and in most cases the electricity itself is made by burning fossil fuels). Unless there have been some dramatic technological improvements recently, solar and geothermal heating are not practical in the northern US where temps can drop well below zero Fahrenheit. Of these options, I'm pretty sure that gas and propane have the lowest environmental impact.
- uvdiv 14y ago
  Electric heat pumps are more efficient than any of those. Whole system included. The combination of {heat engine + heat pump} -- i.e., the power plant generating electricity, followed by the electricity powering a heat pump in your house -- is more efficient than using the same heat in your house directly. E.g.: 1 Joule of heat, in a power plant, can bring to you 2 Joules of heat in your house (through an intermediate of 0.5 Joules of electricity). This doesn't violate the 1st law of thermodynamics. You are not converting 1 Joule of heat into 2 Joules of heat. You are using 1 Joule of heat to move 2 Joules of heat out of a large heat sink (the outside atmosphere, or maybe the ground). It doesn't violate the 2nd law either. A power plant runs on very high temperature differences -- Carnot ratio Th/Tc as high as 5.0 (1,500 K / 300 K). A heat pump runs on very small temperature differences, maybe 1.1 (e.g. 300 K / 280 K). Together, you can translate a small movement of heat, at a high temperature difference, into a large movement of heat, at a low temperature difference.
  - maxerickson 14y ago
    The capital costs of retrofitting a ground source are prohibitive though, so 'just use a heat pump' isn't useful advice for millions of people that live in regions where the air gets cold enough to limit the effectiveness of a heat pump.
  - AaronBBrown 14y ago
    I live in an area of the US where the temperature ranges from approximately -15F to 32F for 3 months of the year. Heat pumps are not particularly efficient in those temperature ranges. In more mild climates, heat pumps are great. It's just not a panacea.

AaronBBrown 14y ago

How go you propose that an individual heat their house if not with gas, propane, oil, or wood? Electric heat, except in the case of perhaps a space heater, is extremely inefficient (and in most cases the electricity itself is made by burning fossil fuels). Unless there have been some dramatic technological improvements recently, solar and geothermal heating are not practical in the northern US where temps can drop well below zero Fahrenheit. Of these options, I'm pretty sure that gas and propane have the lowest environmental impact.

uvdiv 14y ago
Electric heat pumps are more efficient than any of those. Whole system included. The combination of {heat engine + heat pump} -- i.e., the power plant generating electricity, followed by the electricity powering a heat pump in your house -- is more efficient than using the same heat in your house directly. E.g.: 1 Joule of heat, in a power plant, can bring to you 2 Joules of heat in your house (through an intermediate of 0.5 Joules of electricity). This doesn't violate the 1st law of thermodynamics. You are not converting 1 Joule of heat into 2 Joules of heat. You are using 1 Joule of heat to move 2 Joules of heat out of a large heat sink (the outside atmosphere, or maybe the ground). It doesn't violate the 2nd law either. A power plant runs on very high temperature differences -- Carnot ratio Th/Tc as high as 5.0 (1,500 K / 300 K). A heat pump runs on very small temperature differences, maybe 1.1 (e.g. 300 K / 280 K). Together, you can translate a small movement of heat, at a high temperature difference, into a large movement of heat, at a low temperature difference.
- maxerickson 14y ago
  The capital costs of retrofitting a ground source are prohibitive though, so 'just use a heat pump' isn't useful advice for millions of people that live in regions where the air gets cold enough to limit the effectiveness of a heat pump.
- AaronBBrown 14y ago
  I live in an area of the US where the temperature ranges from approximately -15F to 32F for 3 months of the year. Heat pumps are not particularly efficient in those temperature ranges. In more mild climates, heat pumps are great. It's just not a panacea.