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by _0w8t 3213 days ago
Does this work when humidity is high? Water absorbs thermal infrared and emits it back.
1 comments

You can still get cooling, but you get less heat rejection per unit area in high humidity because of the effect you point out.
As someone who is very unknowledgeable about this subject area, what kind relationship between humidity and lost heat rejection would there be?

I ask because as someone who has lived most of his life in southern Florida, this kind of device could reduce electricity bills massively around here, as long as the humidity isn't too much of a problem

You heat the surrounding humid air instead of sending the heat into space.
And that surrounding air will radiate thermal infrared back heating the panel. As was pointed out in another thread, this still may work, but not as efficient as long as some infrared is not absorbed.
If there is even a slight breeze blowing, then wouldn't that move enough of the heated humid air out of the way?
No significant difference. The point is that the more opaque the air is to infrared, the more your panels are in thermal equilibrium with the surrounding air (ambient air temperature) rather than space (2.7K). They're in equilibrium with a weighted combination of those. Doesn't matter whether you heat up the surrounding air by 0.01 degrees.