Furnaces, boilers, air conditioners, heat pumps, mini-splits and ducts.
Heating and cooling sizing
This Sheet is for licensed pros
It counts the materials, costs, permit and inspections for the trade. Here’s what the job involves, what to ask and how to hire a licensed HVAC contractor.
Are you a contractor?
Why this is a pro job
Heating and cooling equipment is sized to the house, wired, hooked to gas or refrigerant lines and vented so exhaust can’t get inside. Refrigerant work needs a certified technician, and a gas or venting mistake can kill. It takes a permit and an inspection.
Hire this out: licensed work with a permit.
How it goes
5 stages
1
Size it
A load calculation for your house, room by room (Manual J in the US). Not the old unit’s size or a rule of thumb per square foot.
2
Pick the system
Furnace and AC, heat pump, boiler or ductless mini-splits, and whether the ducts can carry the air.
3
Permit
The contractor pulls it, plus gas or electrical permits when those change.
4
Install
Equipment, venting, ducts or line sets, condensate drain and power; refrigerant charged and the system started up.
5
Inspect
Final inspection. Keep the start-up sheet and register the warranty.
What you can do yourself
Once the pros are done, these parts are DIY. Each has a Sheet: the materials counted, the tools and the steps.
Licensed for heating and cooling here? Who pulls the permit?
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Did you size it with a load calculation for this house, room by room?
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Can the ducts carry the new system’s air, or do they need work?
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What’s included: removal of the old unit, the thermostat, the condensate drain, the electrical?
These are the general rules. Your state, province or town may add its own: check with your local building department before you start.
Licenses and registration
Hire a heating and cooling contractor licensed for your area — many states license HVAC or mechanical contractors, some through the city or county — who pulls the mechanical permit from your local building department. Gas lines go to a licensed plumber or gas fitter, and anyone who handles refrigerant needs EPA Section 608 certification. Rules change — your building department has the last word.
How to hire a licensed HVAC contractor
This is licensed work: only a licensed HVAC contractor should do it. Ask these questions and check the license before you sign.
Ask before you hire
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Your license number? Look it up on your state’s (or city’s) licensing board website before you sign.
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Will you pull the permit in your name and be there for the inspections?
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Can I have the price and the scope in writing, with the license number on it?
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Did you size it with a load calculation (Manual J) for this house?
•
Is your refrigerant technician EPA Section 608 certified?
Check the license
Look the license up with your state or local licensing board before you sign.
Permit and inspections
The contractor pulls the mechanical permit from your local building department, plus the gas and electrical permits when those change. Keep the approval, the start-up sheet and the warranty with your house papers.
Get quotes from local pros
Quotes from local pros need the online version
StudSheet sends quote requests to verified local pros through your account, so it needs the online version at app.studsheet.com. For now, copy this page and send it to a contractor you trust.
After the work
Painters can patch and paint the holes the work leaves. Never the licensed work itself.