It depends on the cooling load for the home. air conditioners are sized and rated as a matched system consisting of the condenser and evaporator. The capacity of the system changes with the different evaporators. Usually you use either the same size as the condenser or 1/2 ton larger.
If the old unit was a 10 SEER or less. If the old indoor coil has an expansion valve you should be fine but if it has an orifice type metering device then it should be replaced
the model number will most likely have anumber that coinsides with feet such as12=1 ton,24=2 ton,30=2.5ton and so on. some upgrades may have numbers like 32 instead of 30, but that's usually on the inside unit the outside unit generally sticks with the 12=1ton rule
Ton as a unit of measure should not be capitalized. It should be capitalized only at the beginning of the sentence.
a 4 ton unit
The capacity and efficiency would be mostly governed by your indoor coil. When you have a mismatch with the indoor unit being smaller, you will have higher operating costs. The outdoor unit has to work harder to generate the same amount of cooling. This is not a good thing.
Number 8. Rated for 40 amps
That is a 3 1/2 ton unit. one ton of A/C = 12000 btu. The 42 in the model number refers to 42000 btu.
A standard ton of refrigeration is 12,000 BTU/h (3517 W). There for a 2 ton unit is a 24,000 BTU/h unit and a 3 ton unit is a 36,000 BTU/h unit.
3
1 ton per 500 sq ft. so 5 will do
It is an outside condensing unit for a 4 ton split system a/c.
Feet is an unit of volume and metric ton is an unit of mass, you can't compare them directly. We should know a density of items in this container to calculate their mass.