A couple years ago I have estimated that the heat generated by air conditining units is larger than the heat from the sun.

So I assumed that there is about 1 kW of solar radiation per m². In the urban area of St. Louis, there are 2150000 people on 2392 km². The solar radiation therefore causes 2392 GW.

Assuming that every person has an AC unit and that it consumes 3 kW, this would result in 6450 GW due to AC units, being a multiple of the heat coming from the sun.

The estimates are likely wrong. But it seems that AC units have a rather severe impact on the heat in a city. Wouldn't it make more sense to rather use white painted buildings and other passive cooling techniques instead of using so much AC?


closed as off-topic by John Rennie, Jon Custer, Kyle Kanos, sammy gerbil, Emilio Pisanty Nov 13 '17 at 11:39

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  • $\begingroup$ Yes, but would the passive cooling techniques be as effective? Probably not $\endgroup$ – user139621 Nov 5 '17 at 11:39
  • $\begingroup$ ASU did a study a number of years ago & found that it'd raise nighttime temperatures by ~1 C (source) $\endgroup$ – Kyle Kanos Nov 5 '17 at 11:49
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    $\begingroup$ I'm voting to close this question as off-topic because it's a question about the wisdom of using air conditioners not physics $\endgroup$ – John Rennie Nov 5 '17 at 12:31