After lving in the house and accruing a few days of hobo measurements I had a pretty good record of how the house behaved during a typical day in the hot season, April 3-5 in this instance. April 3 turns out to be the second hottest day of the year so far, with temperature on the house deck and bedroom peaking in the afternoon at close to the Don Muang maximum of 37 degrees. Note the circled part of the record, where the bedroom temperature seems to have a little "kick" starting at about 3 or 4 pm. This is caused by the sun striking the dark wood wall panels in the late afternoon, when the sun angle is low enough to slip beneath he roof overhang.
From this and other data we derive the following basic principle: Shade from the fahlang's ancient enemy, the sun, is the first defence against heat in Bangkok.
Though Jack might have done better, in theory, by orienting the house so the long axis was east-west, thereby reducing the exposure to the direct sun, especially in the afternoon (hottest time of day is about 3 pm), other siting conditions governed (as they usually do) so that the roof and wall of the house, the bedroom wall, were exposed to late afternoon sun. Fortunately the light construction of the house does not allow for much storage of heat, so that the roof and wall would cool soon after sunset (not like concrete walls and roofs, which stay warm well into the evening). Note however that the bedroom temperature persists at about 2 degrees higher than the outside air. This may seem like a small amount but it is important when we consider that the threshold of sweaty discomfortfor a well-fanned sleeper is around 28 to 30 degrees.
But Jack and Dah have enjoyed a stroke of luck.
A tall apartment building stood to the west of the house, so that during the hottest part of the year, mid-April to September, the building throws a shadow that arrived at just abouot 4:30 pm! (Yep, when you are site planning you can check all this out yourself on Google)
Two hundred foot tree
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