Which uses less energy to run, a/c or swamp cooler?

Question

If each unit cools the same amount of space, 1600 sq ft. and both are window units. A/C 25,000 BTU...Swamp cooler 0.5 horsepower.

Answer 1

It depends on the size of the unit.  A large swamp cooler would use more energy than a small A/C unit.

Answer 2

Swamp cooler uses a lot less energy - it does not have the compressor an air-conditioner uses to cool the air.  The swamp cooler merely blows MOIST air into the house.  If the house is hot with DRY air, the moist air absorbs some heat, producing a cooling effect!