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Comment by foxyv | Hacker News Reader

About 60% of human body heat is lost through radiation. The cooling you would feel would be proportional to the percentage of the area around you that is covered by these cooling walls. Distance wouldn't cause that much loss because the air doesn't absorb much radiation in blackbody range of humans over distances less than 50 meters.(Infrared range with intensity peaking at 93 thousand angstroms)

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But when I lose that heat through radiation it would presumably bounce around the room and not much reflects back onto my body.

So I’m not seeing how much this really helps. My radiated heat shouldn’t be returning to me anyway.

Also not sure how effective this system really is, but it helped me to imagine my walls reflecting visible light as if I were in a room of mirrors and thinking about how many higher order reflections of myself would be able to reach just my pupil, multiplied by the surface area of my body.

You lose heat through radiation, but the materials surrounding you are also radiating heat.

You emit thermal radiation at a black-body temperature of 37C or so to the environment, but the average surface nearby (in a non-air-conditioned environment) will be radiating back at 30C or so, for very little net heat loss.

The innovation described here is to replace the local environment with a chilled one that interacts only by radiation. The air with very little mass contributes negligible radiation to the system, so you radiate heat outwards but receive little in return.

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