Chapter 12

Choosing a New Air Conditioner or Heat Pump

A replacement system is a long-term home investment. The right choice depends on the home's heating and cooling loads, duct system, electrical service, budget, comfort goals, and local climate.

A heat pump moves heat rather than creating it through electric resistance. In cooling mode it operates much like an air conditioner; in heating mode it reverses the refrigerant cycle to bring heat indoors. Some homes use a heat pump with supplemental heat. Other homes use a straight-cool air conditioner with a separate heating system.

Efficiency labels and ratings can help compare equipment, but ask the contractor to explain what the rating means for the specific model and system combination. Confirm that the quoted indoor and outdoor components are approved to operate together.

Proper sizing is critical. Ask whether the contractor performed a recognized heating and cooling load calculation using the home's construction, insulation, windows, orientation, occupancy assumptions, and local design conditions. A rule of thumb based only on square footage is not a substitute for a load calculation.

The proposal should identify model numbers, capacity, efficiency ratings, thermostat, filter arrangement, condensate management, duct modifications, electrical work, permits, start-up and commissioning, warranty terms, and disposal of old equipment. Ask who will obtain permits and who is responsible for inspections.

Do not select equipment solely because it has the highest advertised efficiency or the largest capacity. A good system is properly matched, correctly sized, installed to manufacturer requirements, and tested before the contractor leaves.