What is the meaning of the British Thermal Unit (BTU) on an air conditioner?

So in my 300 square foot living room, I upgraded my air conditioning. I went from an 10,000 btu window air conditioner and upgraded to a dual hose 14,000 btu portable air conditioner. In NYC it is not uncommon to see 90 degree heatwaves in the summer. I have noticed a significant cooling with the new unit. On a 90 degree humid day, my window unit would struggle to cool my living room down below 77 degrees while with the new portable air conditioner it easily maintains the temperature around 72 or 73 degrees on a 90 degree day. It is currently a cool 71 degrees in my bedroom/living room combo which is nice. I think the higher BTU amount contributed to better cooling and a lower temperature. Whenever I set below 70 such as 64, it struggles but then again it is a 300 square foot bedroom/living room. I also use the stove in the summer during the day so the air conditioner cools well considering that too.

5 Answers

  • 4 weeks ago

    It's a measurement of the units ability to transmit heat. Your A/C is actually a heat exchanger conveying inside heat to the outside. The rate or ability to do this is expressed in BTU's. There are more complex scientific definitions but I like to keep it simple.  

  • Anonymous
    1 month ago

    I have to use Google to get the exact answer SO you can do that too.

  • Droopy
    Lv 5
    1 month ago

    Your probably about right as far as size goes. its a little over 1 ton of cooling which cools bout 600 sqft on high-end.   Once you factor in the Btus from people, cooking, tv,ect.  Then insulation in exterior walls which  is gonna vary depending on age of the building. 

  • 1 month ago

    Technically, one Btu is the amount of heat required to raise the temperature of 1 lb of water by 1°F. 

    Domestic and commercial heating and cooling systems such as water heaters, boilers, furnaces, air conditioners and heat pumps in the United States tend to be specified in thousands or tens of thousands Btu/h, which measures the rate at which heat (or cooling) can be transferred  The higher the Btu the more powerful it is.

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  • 1 month ago

    for ever sq ft of room you need 20 btu ..so a 300sq ft needs a 6000 btu unit ..plus add 600 per person ..so if you regularly have 3 persons in room add 1800 to the 6000...so you have oversized by a fair bit ..the other factor ..and its important is ceiling height ..a room with a 10 ft ceiling will need a lot more btu`s 

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