Reading an HVAC Replacement Quote: What to Ask For

The equipment rating assumes a correct installation.

ENERGY STAR’s bid comparison checklist states that more than half of new heating and cooling systems in U.S. homes do not perform to their rated efficiency because of improper installation, and that poor installation can reduce performance by as much as 30%. The symptoms go beyond the bill: poor dehumidification, dust from leaky ducts, and uneven air distribution.

Size should come from the house, not the old unit.

ENERGY STAR says the contractor should calculate the home’s heating and cooling loads using ACCA Manual J or an equivalent method, because proper size is vital to efficiency and comfort. Replacing “the same size as before” repeats any mistake the last installer made — and insulation, windows, or air sealing added since then change the load. The BTU sizing guide explains the idea for a single room.

An indoor coil and outdoor unit have to be rated together.

The checklist asks for an AHRI certificate documenting that the system’s components are properly matched, the Manual J calculation, and records of any measurements or testing, left with you after installation. For air conditioners and heat pumps, ask the contractor to confirm correct refrigerant levels and airflow across the coil, and whether new refrigerant lines will be installed rather than reusing the old ones.

A new system on leaky ducts wastes part of its output.

ENERGY STAR’s duct sealing guidance says leaky ducts can reduce heating and cooling efficiency by as much as 20%, and the bid checklist recommends total duct leakage of no more than 20% in most cases. A good contractor inspects the whole duct system, seals leaks and connections with mastic, metal tape, or aerosol sealant, insulates ducts in unconditioned spaces to at least R-6, evaluates airflow afterward, and — because sealed ducts can change pressures in the house — checks that gas or oil appliances vent properly with a combustion safety test.

Ask each contractor the same list, and compare the answers, not only the totals.

1. Will you calculate the size with Manual J?
2. Will you test the ducts, and seal them to a stated leakage level?
3. Will you provide an AHRI matched-system certificate?
4. Will you verify refrigerant charge and airflow after installation?
5. Do you follow ENERGY STAR Quality Installation guidelines, and offer third-party verification?
6. Which local rebates apply, and will you file them?

The federal tax credit for heat pumps ended for equipment installed after 2025, so any 2026 quote should be compared at full price.