Yes, a 3-ton air conditioning unit can effectively cool a 1250 square foot space, as a general rule of thumb suggests that you need about 1 ton of cooling capacity for every 400 to 600 square feet. However, factors such as ceiling height, insulation quality, sun exposure, and the number of occupants can affect the actual cooling needs. It's advisable to consult with an HVAC professional to ensure the unit is appropriately sized for your specific situation.
3.5 ton
1 and half to 2 ton
2.5 ton should do it
If the house is well insulated, a 4 ton unit should work pretty well in about 1800 sq feet. But if the insulation is not good enough, then you need to go with a larger unit.
4 ton depending on construction and location.
3 ft = 1 yard so 1250 ft = 1250/3 = 416.66... (recurring) yards.
1 ton per 500 sq ft. so 5 will do
2.5 ton a/c unit
2.5 ton
No. You at least need a 3.5 to 4 ton.
A 4 ton unit will be adequate usually 1 ton per 400 square ft of living space
A 3 ton is ideal more for a house that's 1200 sq. ft, I would recommend a 2.5 ton