Resources
Guides for people who pull permits.
Plain-English answers to the questions we hear every week.
Guides
Pick your guide.
Homeowners
Most HVAC quotes are sized by square footage. Here is why bigger usually means worse, and how to know the right size before you sign.
Home builders
You would never ask a framer to price a house before the plans exist. HVAC deserves the same order of operations.
HVAC professionals
Rules of thumb built a lot of businesses. Real designs build reputations. Here is how contractors use an outside design partner without adding payroll.
Permit requirements
What building departments in KY, TN, the DC region and Florida ask for, with sources.
Tools and articles
Everything else.
HVAC load calculator
Four quick steps about the house. A designer follows up with accurate estimates.
See the work before you send the plans
Manual J, S, D and N, duct design sets and energy compliance, as delivered.
Why you need a Manual J calculation
Rule-of-thumb sizing is fast and usually wrong. Here is what the Manual J does instead, and why building departments ask for it.
HVAC load calculation requirements by state
There is no single national rule. Here is how the requirement flows from the model codes to your county, and the quickest way to confirm what your permit needs.
Fast load calcs for permit deadlines
Most delays are missing information, not design time. Here is what to send the first time so your calculations come back fast.
Fast estimates
Send the plans. Get an estimate.
Send us your questionnaire and plans, and we’ll get you an estimate right away. Reach out during office hours and you’ll hear back within 30 minutes, whether it’s an email, text or call.