HVAC

After reading a lot, I got a 8500*2 BTU/hr for two rooms - MBR and CBR. I must say that its super cool (in Oct with little Sun due to Haze). The salesman recommended 12000 for MBR and 9000 for CBR. But I took my chances and went with a lower capacity. My advice to people is, go for smaller capacity AirCon, unless your unit has west facing sun and you want to run the aircon in afternoon heat at 18C during peak summer in May. Else, 8500 BTU/hr for any sized room below 150sq. ft should be cool enough. Apparently, Energy Star ratings from USA that 150 sq. ft room requires only about 5000-6500 BTU/hr is a good advice. I am running my AirCon between 23C to 26C and its perfect capacity for me I think.

I have done extensive reading online and have come up with different numbers. I am listing important things here: 1. Based on e2singapore and coolserve, we have to size it as area*65 (area is in sq. ft). Hence, a 150 sq. ft room requires 9750 BTU/hr. 2. Based on "Energy Star" from USA, a 150 sq. ft room requires only 5000 BTYU/hr. Further, I have checked other US govt. sources and they say that a 850 sq. ft home requires 3 tons (3*12000 BTU/hr). Hence, roughly a 150 sq. ft room requires 150/850*3*12000 ~~ 6500 BTU/hr in Texas, USA. Considering that Texas is already very hot, my question is, are we oversizing our AirCons in Singapore ???