HVAC guides

Start by writing down the problem you're solving — not the product you think you need. "The upstairs is 8 degrees warmer than downstairs" leads to a different conversation than "I need a new AC." A good contractor will investigate airflow and duct design before quoting equipment.

When the bids come in, compare them line by line: equipment model numbers, AHRI match reference, duct work included or excluded, electrical work, thermostat, permit, disposal of the old unit, and the warranty terms. ACCA notes that Manual J, S and D are referenced in building codes nationwide — ask which of them were actually performed for your job.

Finally, plan the timing. CBS News advises replacing proactively rather than in an emergency; you get better pricing and clearer thinking when you're not in a heat wave with no cooling.

How to choose

Write the scope yourself

One page: what's being replaced, what's being left, what's included. Hand the same page to every bidder. This alone makes quotes comparable.

Verify credentials before the visit, not after

State contractor license through your state board, EPA Section 608 for refrigerant work, plus general liability and workers' comp insurance.

Ask to see the load calculation output

Not a promise that one was done — the actual room-by-room result. ACCA's Manual J is the standard method.

Never sign in the first visit

Same-day-only discounts are a pressure tactic. A legitimate price will still be there tomorrow.

Hold a retention until the final inspection passes

If a permit is required in your jurisdiction, tie your final payment to the inspection sign-off.