How much area can 1hp of this brand can cool - Carrier XHB123D X/Y Series Heat/Cool Air Conditioner

The Statement they all work the same is not 100% correct, The AC untis Like all machine have a duty cycle rating, Andd the higher the duty cycle the more durable the unit become. so a 2 ton unit rated at 2% Will not last as long or preform as well as a unit rated the same tonage but at 50% duty cycle, but the unit may cost more.

The 'rule of thumb' is 1 ton of AC for every 600 sq feet of a well insulated space (400 sq ft if not well insulated)- for example if the space to be cooled is 1200 sq ft - and is well insulated - you would require a 2 HP unit. 1200 divided by 600 = 2

if the space was not well insulated - you would require a 3 HP unit. 1200 divided by 400 = 3

note; 1 ton of air conditioning - is sometimes referred to as 1 HP or 12000 Btu. Whether you call it 1 HP or 1 Ton or 12000 Btu - they all three mean exactly the same thing.

take this example - 2 tons of air conditioning can also be referred to as 2 HP or 24000 Btu.

fyi - it doesn't matter what 'brand' - they all work off the same principle.

hope this helps