[hpkuarg]

> it’s much easier to warm up in cold weather than it is to cool down in hot weather

May be true for the human body, but when you're talking about heating a living space to a comfortable temperature versus cooling the same, in the majority of places (at least in the US) it takes way less energy to accomplish the latter.

Even in a hot place like Dallas, TX with an average daytime high of 97 degrees Fahrenheit in the hottest month, it's only a 20-degree differential to bring it to 77 degrees indoors, vs. an average overnight low of 38 degrees in the coldest month, where you would need to bring it up 30 degrees and might still feel cold inside.

This is not to mention how much more energy-efficient air conditioning (which just moves heat around) is compared to furnaces (which generate heat from fuel).

[pdonis]

It's not the heat, it's the humidity. For typical summer conditions in Dallas (even more so in, say, Houston or Brownsville), if I'm remembering the numbers from my time as an automotive HVAC engineer correctly, it takes 5 to 6 times as much energy to dehumidify the air as to cool it. And those are by no means the worst conditions on the planet: try southeast Asia or equatorial Africa.

It's true that you can claw some of that back from the fact that A/C can have a coefficient of performance greater than 1, but COP also gets worse (i.e., closer to 1, less of an advantage) as the conditions get more extreme.

[SoftTalker]

Yes, because dehumidification involves a phase change (water vapor to liquid) and the heat of vaporization is much higher than needed to effect a simple temperature change in dry air.