Air Conditioner Wattage

I have seen many AC's nameplate but there is no mentioned two distinct watt ( electrical watt and mechanical watt) . There is always only one mentioned watt for electrical and btu/hr for mechanical.

So, it is better to post the nameplate to comment you more better about this.

Since you have the nameplate which contains all data ( ampere, voltage and wattage) I think there is no need for calculating from btu/hr.

The maximum wattage divided by the voltage will give you the current; the only number to concern yourself with. If two wattages are given, is the A/C a dual voltage machine? Some A/C's have a heat element built in so the unit can be used for both cooling or heating.

Usually the cooling capacity of a.c are mentioned on the name plate as kW. In old units it is referred as Tons of refrigeration. ( TOR or TR). I T.R = 12000 Btu /hr.=211 kJ/Min= 3.52kW.It is different from the compressor motor power rating on the name plate. Former on is thermal unit and the later one is the mechanical unit.

This was explained on a previous thread.

If the AC is not what they call a heat pump (trade misnomer since all ACs are heat pumps), meaning that it is a unit intended for cooling only, then the higher wattage is the thermal (or what you call mechanical) cooling wattage. The other one , which will be roughly half the value, will be the electrical.

If the AC is built for cooling and heating, then the two might be electrical wattage since the 2nd could involve some heating element to supplement... longer story.

In your case I thing the 1st paragraph applies.(since you are mentioning BTU/hr....??is it on the name plate? if so, then read carefully what is there and there should be a mention of what each value is for.

2- Convert the BTU/hr to BTU/sec then this is almost the watts for cooling. Divide by 2 and you get the electrical watts for the unit. for the purpose of wiring (cable sizing etc)add 20% at least to cover any errors you might make etc.