Watch this 7 minute video on inspecting emergency lighting

HUGE mistake at 01:15
Heat moves from Hot to Cold, NOT Cold to Hot… unless influenced my man’s intervention.

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Didn’t hear anything about heat movement, he merely said cold air will migrate through the opening. Stack effect, hot air moves up - cold air enters through lower openings - condensation occurs on surfaces where the hot and cold air meet.

I agree to a point Bob, but in this scenario with a small opening, I believe it to be more a case of pressures… low pressure vs high pressure. If we were talking a larger opening such as a doorway, I could see it more your way with stack effect. Anyway, I felt the repeated use of the word “migrating” was inappropriate and possibly out of context. As it was a video about Electrical, he should have stuck with that subject and saved the Thermal Dynamic opinions for another course. A simple “needs to be sealed” would have sufficed. Otherwise, a good basic video for newbies.

I see your point. I didn’t really learn anything about emergency lighting anyway! His big mistake was calling the 240v feeds separate phases.

Yup, pretty well didn’t even go there, except for one very important point that newbies (and most veterans alike) usually don’t even consider… (Battery backup) Emergency exterior lighting for the egress path when exiting in the dark or when a power failure.

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Just a 12 or 24v gell cell (basically a lead acid battery). I’ve got one in my attic floodlight for inspections.