Air conditioner size vs Room size

Discussion in 'Consumer Electronics' started by Harley, May 17, 2008.

  1. Harley

    Harley New Member

    I am in marker for new airconditioner and am not sure about the size of air conditioner to buy. So, i googled and found that a room of size 150-200 sft, 6000BTU (0.5 ton) is enough. But the sales man recommended 1.5 ton for that size.
    when I gone through some threads, people are using 1.5 ton for this size of room.
    so, i am wondering what is the right size? is google right or wrong with calculations? anybody has any experiece with .5 ton in 150sqft room?

    one more thing, Samsung india website recommends 1.5 ton for 150-200 sft room. but Samsung USA website recommends 6000BTU for the same size room. so, are we misinformed or am I missing something here?
  2. OP

    Harley New Member

  3. HailStonE

    HailStonE Well-Known Member

    The variation in sizes of room & tonnage is 'coz India is a tropical country & temps are much higher than in US generally so while they can cool a 200 SqFt room with 0.5 tonnage... We still need 1.5 ton for our cooling needs....

    Also do keep in mind the insulation they use with AC's while we hardly use insulated establishments....
  4. OP

    Harley New Member

    I realy cant buy that the temps in US are much lower than in India. Typical summar in Florida or Arizona is as bad as summer in India.
    and using 1.5 ton instead of .5 surely looks like overkill even considering the insulation and the temperatures.:huh:
  5. amityrock

    amityrock New Member

    dude.. r u kidding me.. temps in certain parts of us (read extreme) like texas might just be close to delhi/ but on the whole the avg temp of us is like 15c cooler than india for sure.. maybe even more.. now that increases the tonnage reqt gr8ly .. cause in us u just need to cool from max 30c to 22-24c.. whereas in india u need to cool from 42c to again 22-24c.. an hence the massive diff!!

    btw if ur rooms less than 140 sqft u could consider 1-1.2 tonnes .. but anythin more an u surely need 1.5t.. an it also depends on which part of india ur situated in like bbay doesnt need as much tonnage an delhi does..!!
  6. smAsh

    smAsh Well-Known Member

    0.5 Tonne is sufficient only for small cabins/rooms , not for the rooms of size 150-200 sqft. The choice of AC not only depends on the size of room but also the number of people occupying it and the number of appliances generating heat in the room (like TV, Computer etc). Further if the room is exposed to direct sun light then definitly you need a bigger AC.

    On an average 120-200 sqft room can be cooled with 1.5 tonn AC. Buying an AC of less capacity will not save any bill because its compressor will be running all time. Again, buying an AC of higher capacity will not save bill because it is already on higher side of elec. consumption.

    For furthr information, check this guide:-
    Compare India - Buying Guides - Airconditioners (Window) - Airconditioners (Window)
  7. blr_p

    blr_p Well-Known Member

    There's more to sizing than just room area :)

    Try these calculators from Blue Star, Daikin & Hitachi, might be more helpful as they are for India.

    Position matters as well, ideally don't place the AC opposite a door or the cool air leaks out otherwise keep that door closed.
    The_Falcon likes this.
  8. HailStonE

    HailStonE Well-Known Member

    The point Harley is making is why in US lower tonnage is suggested to cool a 150-200 SqFt. room while in India a higher tonnage is suggested....

    I may be wrong in my view & others can improvise here....
  9. kunalthesarkar

    kunalthesarkar Well-Known Member

    thumb rule for acs is how much sq ft
    i.e 120sq fet = 1 ton ac

    now u can calculate.
    this i am telling you as i have done too much research while i was buying an ac.
  10. OP

    Harley New Member

    I got my answer through google. Best way to calculate the size of the AC is using Manual J method. so, size of the room only does not warrant the size of AC. it depends on many other factors like location of room, persons using the room, equipment in room, windows, walls facing the sun, windows facing the sun etc.
    so, if you are using your ac only in nights, then 1 ton is enough for 250sft too.

    Well. Thanks for the replies.:cool2:
  11. manisha0109

    manisha0109 Member

    I went through this post. I wanted to ask you about the final purchase that you made. What size AC did you finally buy. How is the performance of the AC?
  12. Crazy_Eddy

    Crazy_Eddy Well-Known Member
    Super Mod

    The user hasn't logged in since 2009, so you might not get a reply. If you're looking for a heat load calculator taking into account all room factors like Harley mentioned, give this a try :

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