We have a 4x4 fixed skylight over our kitchen. It's mounted on a 4'x4' 2"x8" rim we installed on the roof. I've decided the kitchen would be much cooler if the skylight opened and hot air was able to rise out of the kitchen. So I'm thinking of adding another rim of some kind on top the existing rim with openings in it which can be uncovered in summer and covered over in winter. Anyone have any idea how much open area is needed to get a noticeable flow of air out of the room? I temporarily removed the whole skylight a few minutes ago and the room cooled down substantially in a couple of minutes.

Nobody makes a 4x4 opening skylight that I can see and I probably wouldn't want to spend that much money anyway.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13