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by Scoundreller 1813 days ago
> What's the peak here? Why 1am?

I wondered this too. Maybe contraction or rate of contraction?

Sun has gone down, outdoor temperature is dropping, max heat radiation out if the sky is clear, and everybody is home so A/C is on in all units.
1 comments
aaron695 1812 days ago
The coldest is a bit after dawn. So the previous dawns should have stress tested it. It should fail when the stress is around maximum under this Hyatt peak theory.

Max rate of change of temperature is sunset and sunrise. Rate of contraction I'd expect similar?

I'm not sure AC would change the thermal mass of a building much. One cubic meter of air weights 1.2kg. Changing the concrete walls would be hard.

A drunk hitting a pole at speed in the carpark would fit perhaps. Drunkenness to an empty carpark would be high.

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Scoundreller 1812 days ago
> The coldest is a bit after dawn.

The building (and deck surface) will continue to radiate heat throughout the night on a clear night, especially with few obstructions like a waterfront building has. That's how crops can frost with airtemp > freezing, and why the guidance is to cover your plants. It's not to insulate them against convection.

Counterintuitively in this scenario, this effect is greatest when the wind is calm.

https://en.wikipedia.org/wiki/Radiative_cooling#Architecture

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