QUOTE(PangurBan @ Jan 22 2011, 11:02 AM)
Hot air cannot flow in from outside because I close all the doors and windows, esp if I have the aircon on downstairs. But during hot weather I notice hot air tends to flow up and get stuck inside the stairwell. I also plan to knock a hole in my bedroom, install a fan and suck cool air in at night.
Caaan, unless your door and window is air sealed
What you plan to do to the stairwell in order to suck the hot air out is theoretically correct. Only the timing of suction matters because you only such the hot air out when the outside air is cooler. I suggest to use a timer to automate the exhaust fan.
QUOTE(PangurBan @ Jan 22 2011, 11:06 AM)
Hmmm, brother buy ipad. sister buy coach handbag lor.
Aiyoo...!! bankrupt la like that.
QUOTE(stimix @ Jan 22 2011, 11:07 AM)
Your fav bird nest lor

That's one good suggestion but cleaning it is too hassle.