Start with the home’s load and your comfort priorities
Ask what information supports the selected equipment capacity. ENERGY STAR recommends using the actual characteristics of the home, and its bid checklist asks for a Manual J calculation or equivalent. The number on the old unit is useful history; by itself, it is not a new assessment of the home.
Tell the contractor about persistent room differences, planned additions, changed windows or insulation and how you use the rooms. Ask which of those concerns the proposal addresses. If two quotes recommend different sizes, request the design basis for each rather than assuming that more capacity is automatically better.
Sources: ENERGY STAR: HVAC quality installation · ENERGY STAR: heating and cooling bid comparison checklist
Compare the exact equipment combination
Record the outdoor model, indoor coil or air-handler model, heating equipment where applicable and the proposed control. An efficiency rating belongs to a defined equipment combination. ENERGY STAR’s checklist asks for matched equipment and an AHRI certificate documenting the combination.
Ask what the proposed features mean for your priorities. Staging, variable operation, sound and control options should be explained with the exact models. If an existing indoor component will remain, have that choice and its compatibility documented. A brand name or a headline rating alone leaves too much of the comparison unanswered.
Sources: ENERGY STAR: heating and cooling bid comparison checklist · Carrier: single-stage, two-stage and variable-speed air conditioners
Find out what the duct assessment actually established
Ducts and return pathways affect how the selected equipment serves the rooms. ENERGY STAR calls for evaluating ducts and bringing airflow into line with manufacturer requirements. Ask which parts were inspected, what measurements or testing were performed, and what could not be reached.
If the proposal reuses the existing ducts, ask how their condition and airflow suitability were evaluated. If it includes modifications, connect each change to a finding or design need. Keep a disconnected run, leakage sealing, insulation repair and a room-airflow redesign as identifiable scopes. A new outdoor unit does not explain how an existing uncomfortable room will improve.
Sources: ENERGY STAR: duct condition and performance · ENERGY STAR: HVAC quality installation
Make the installation scope comparable line by line
Use the same questions for every proposal. A simple Included / Reused / Excluded / Unanswered notation is enough. Do not turn a blank into an assumed inclusion, and ask what “as needed” means before it becomes an extra charge.
- Equipment and controls: exact models, matched components and features you will use.
- Air distribution: transitions, duct changes, return pathways and insulation work.
- Connections: refrigerant lines, drains, electrical and any fuel or venting work.
- Site work: supports, access, equipment removal and cleanup.
- Approvals: any required permits and inspections, with the responsible party identified.
- Handover: startup checks, operating instructions, registration assistance and written coverage.
- Changes: how an unexpected condition will be explained, priced and approved.
Sources: ENERGY STAR: heating and cooling bid comparison checklist · ENERGY STAR: evaluating contractors and written estimates
Ask for startup evidence, not just a statement that it runs
Commissioning means checking and documenting how the installed system operates. Ask what startup checks are included and what record you will receive. The useful evidence connects the installed equipment and its settings with the manufacturer’s requirements; a thermostat display by itself is not a complete installation record.
ENERGY STAR highlights airflow, refrigerant charge and duct evaluation as quality-installation issues. Ask how applicable results will be documented, which controls and drainage functions will be demonstrated, and whether any check needs a later visit because of conditions at startup. A deferred check should have an identified follow-up, rather than disappearing from the scope.
- Which installation and operating measurements will be retained?
- What manufacturer requirements are those results compared with?
- What was adjusted or corrected during startup?
- Was any work or test deferred, and who follows up?
- Will the completed record be available with my equipment documents?
Sources: ENERGY STAR: HVAC quality installation · ENERGY STAR: professional maintenance checklist · ENERGY STAR: heating and cooling bid comparison checklist
Keep ownership costs and coverage understandable
Compare the complete installed price first. If financing is part of your decision, review the actual lender disclosures separately so the payment amount does not obscure differences in the project. Ask about required maintenance, accessible filter locations, replacement materials and any connected-control account you will need.
Keep the equipment manuals, model and serial details, registration confirmation, final scope, startup record and applicable warranties together. Manufacturer parts coverage and contractor workmanship coverage are separate documents. Ask which costs and conditions each covers; do not fill a gap with a general advertisement or an earlier verbal summary.
Sources: ENERGY STAR: heating and cooling bid comparison checklist · ENERGY STAR: evaluating contractors and written estimates
Use unanswered items to guide the next conversation
For example, one proposal may include duct changes and a documented startup record while another lists equipment with existing ducts to remain. That is an illustrative comparison, not a claim about a particular contractor. The next step is to ask what each design assumes and what each price includes. Once the differences are clear, you can decide which option fits the home and your priorities.
Bring your comparison sheet and comfort concerns to S&S. Ask us to explain the design, the work around the equipment and the records that accompany the installation. “When you want it done right” starts with understanding the complete project before choosing it.
General homeowner information from S&S HVAC. Equipment instructions and the approved project scope govern work on your system. Source links support the guidance; they do not imply a manufacturer endorsement.

