Manual JPermitsSizing
Manual J vs. rule-of-thumb sizing: why 400 sq ft/ton fails permits
Why ACCA Manual J load calculations beat square-footage rules of thumb — and what AHJs actually look for on a stamped report.
6 min read
Insights from the design desk
Practical guides on Manual J, S, D, T, energy calcs, and permitting — written by the designers who stamp the reports.
Manual SEquipment
Manual S: the equipment-selection step contractors skip — and shouldn't
Manual J tells you the load. Manual S picks the equipment that matches it. Here's why skipping S is how oversized systems get installed.
5 min read
Manual JField guide
How to read a Manual J report: a contractor's 5-minute walkthrough
The four pages every contractor should review before installation: project assumptions, room loads, system summary, and infiltration.
7 min read
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