Comment by mchannon | Hacker News Reader

Comment by mchannon | Hacker News Reader

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Other suggestions here are good in terms of how to track it, but I suspect you don't need to track it beyond what you already know- it's most likely that air conditioner.

Even if every other electric appliance in your house doubled or halved its power consumption, it wouldn't move the needle near as much as the biggest energy user in the house.

If your AC is more than 5 years old, consider replacing it. Not only do they eventually wear out, wasting more energy, but newer ones can be more energy-efficient.

Consider buying a cheap mister for your AC's radiator. It uses a small amount of water to conduct the heat off the coils. Cool-n-save, Mist-n-save, Mistbox.. may want to soften the water you use to avoid scale deposits.

The smartest thing would probably be to explore a 5kW PV system on your roof. Not only will it remove heat from your roof but it will also save a lot on your air conditioning no matter how efficient it is nor how hot it gets outside. SC's government and utility incentives (visit dsireusa.org) look a lot like those in PV-friendly states from 5 years ago (which is to say, ridiculously good for the homeowner).

> "If your AC is more than 5 years old..."

Most A/C units will work perfectly fine for 10-15 years if proper maintenance is being done.

Do those mister's really work? I remember liking what I saw from the promo's but there seemed to be a lot of people claiming snake-oil.

Evaporative cooling is more useful in dry arid climates. If you live in Pheonix, AZ, you may get by with nothing but a swamp cooler [1]. If you live in Phenix City, AL, you'll just get mold because the relative humidity is high. So if spraying water on your coils will cool them, then a swamp cooler may be a better option.

At large scale, evaporative cooling works even in humid climates but by large scale I mean upwards of 20 tons [2] square feet plus a place to put industrial level noise.

[1]: https://en.wikipedia.org/wiki/Evaporative_cooler

[2]: The 20 tons is based on the current Trane US product line. It equates to upwards of 12,000 square feet of conditioned space.

I've never owned one, but the physics are pretty straightforward. The greater concern is longevity.

I seem to recall a refrigerated air unit will use about 15% of its energy to cool its hot side and about 85% to pump the heat from cold side to hot side. So even if this eliminates that entire 15%, you're still going to be putting a lot of juice into that heat pump.

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