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Tweefo (January 24, 2017, 15:30:19 PM):
My wife and a partner own a small private school. Up to now, they operated out of an old house that was converted into classrooms and some wendy house classrooms. A bit shabby. However, they are building new premises on land that was donated to them by the municipality. Phase one is now nearing completion but look at the ceilings. Photo 1 and 2 are three classrooms front and back. The ceiling in each is 75% normal but then it slopes up at a 45° angle and at the top, there is a louvered panel, with a glass pane on either side. On either side of the room, there are two small windows that can open. The other windows cannot open. The idea is that a "convection" current of air will keep the room cool without an aircon. Will this work with 25 children in the class? It's very hot up here on the highveld at the moment and those rooms are remarkably cool now, but of course I was alone in there.

Mefiante (January 24, 2017, 16:17:02 PM):
Provided the outside air temperature is relatively cool, at least on the side where the roof is at its lowest, it should work quite well. The basic idea behind the design is that warm air rises due to its lower density. It will rise into the inclined recess in the ceiling and out through the louvred outlet vent. As the warm air rises and exits on the high side, it is replaced with cooler fresh air from the outside at the low side. Such a temperature-driven cycle is the essence of a convection current. The greater the temperature difference between the air on the inside and that on the outside, the faster the air will move (within limits determined primarily by the cross-sectional areas and geometries of the inlet and outlet “ports”), so if they’ve done the design correctly for the expected ambient temperature conditions and the number of people, it should work fine. In winter when it’s cold outside the inlet and outlet “ports” need merely be constricted or closed entirely to keep the warm air inside.

One possible enhancement to this system is to channel the fresh air through a mist chamber before it enters the classrooms. In a mist chamber (which needn’t be huge), very fine water sprays (misting nozzles) add some evaporative cooling and also increase the air’s relative humidity. If the outside air is cool enough already, the water merely needs to be turned off. The water consumption would be very low but a good minimum pressure would be required for the misting nozzles to work properly.

brianvds (January 25, 2017, 06:04:00 AM):
My own experience at school would suggest that it doesn't matter what you do: in summer the classroom is too hot, and in winter too cold. :-)
Rigil Kent (January 25, 2017, 06:43:06 AM):
Nice building design. Are you planning on painting the roof white, which may or may no be beneficial ?
Tweefo (January 25, 2017, 14:51:07 PM):
Nice building design. Are you planning on painting the roof white, which may or may no be beneficial ?

Don't know. The white paint on the walls is the undercoat, those walls will be an "earth tone" color. They also started the brick laying for the walls on the 2nd phase today, even though phase 1 is not finished yet. Phase one was supposed to be done at the end of January, but that is not going to happen. There is a saying that one can double the time that the builder tells you, and then add another week or two.


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