Subject: RE: [Bldg-sim] insulation hot humid climates
Hello Aushim,
I suspect Bangladesh has a tropical monsoon climate, which I don't have any
information for. But, prescriptive requirements for the tropical island
location of Kingston Jamaica are as follows:
WALLS: No. insulation, if solar absorptivity < 0.7
WINDOWS: clear glass with internal blinds, Window-to-Wall ratio <
0.35
ROOF (metal): (a) No skylights, U-value = 0.12 Btu/hr-sq-ft-degF, solar
absorptivity < 0.7; or
(b) Skylights with U-value = 0.8
Btu/hr-sq-ft-degF, 2% of roof,
opaque roof U-value = 0.09 Btu/hr-sq-ft-degF, solar absorptivity < 0.45
You might consider a solar chimney.
http://en.wikipedia.org/wiki/Solar_chimney
You would want to minimize air leakage in the building envelope to
maximize the draw of cool air from underground.
I think I've seen configurations where there is no actual chimney, but
rather a chimney effect is realized by a vent located in the top of the
wall across the room from the vent from the underground. (Same as shown
above, but with no actual chimney constructed on the outside of the
building.) Since you will have a metal roof, you should have a lot of
hot air at the ceiling that will ventilate when the cool air vent is
opened on the floor thus cooling the room.
Aushim;
do you have any pictures of the exising hospital so we can better understand the structure.
thanks
Subject: RE: [Bldg-sim] insulation hot humid climates
Hello Aushim,
I suspect Bangladesh has a tropical monsoon climate, which I don't have any
information for. But, prescriptive requirements for the tropical island
location of Kingston Jamaica are as follows:
WALLS: No. insulation, if solar absorptivity < 0.7
WINDOWS: clear glass with internal blinds, Window-to-Wall ratio <
0.35
ROOF (metal): (a) No skylights, U-value = 0.12 Btu/hr-sq-ft-degF, solar
absorptivity < 0.7; or
(b) Skylights with U-value = 0.8
Btu/hr-sq-ft-degF, 2% of roof,
opaque roof U-value = 0.09 Btu/hr-sq-ft-degF, solar absorptivity < 0.45
Best regards,
Paul Hay
Aushim
You might consider a solar chimney.
http://en.wikipedia.org/wiki/Solar_chimney
You would want to minimize air leakage in the building envelope to
maximize the draw of cool air from underground.
I think I've seen configurations where there is no actual chimney, but
rather a chimney effect is realized by a vent located in the top of the
wall across the room from the vent from the underground. (Same as shown
above, but with no actual chimney constructed on the outside of the
building.) Since you will have a metal roof, you should have a lot of
hot air at the ceiling that will ventilate when the cool air vent is
opened on the floor thus cooling the room.
Paul Grahovac, LEED AP