Heating & Cooling

Verifying the exact furnace, coil, and condenser you are being sold: AHRI numbers, efficiency ratings, sizing, and the refrigerant change.

Heating & Cooling September 11, 2026 R-410A Phase Out: Can You Still Repair Your Existing System The ticket says R-410A is banned. The rule is narrower: what 40 CFR 84 prohibits, what a 2026 rule removed, and why a condenser-only R-454B swap fails on paper. 16 min read
Heating & Cooling August 30, 2026 Manual J S and D: How to Tell If Sizing Was Skipped A bid that says 'sized per Manual J' owes you a report with nine inputs on it. What each ACCA manual covers, what code requires, and the tells none was run. 10 min read
Heating & Cooling August 19, 2026 AHRI Directory Lookup: Verify the System on Your Bid Your estimate names a condenser and a coil. The AHRI Directory decides whether that pair was ever rated together, and which columns say it wasn't. 11 min read

About this section

The habit started with an estimate that named a condenser model the AHRI directory had never heard of. Since then Bram Ellery has read every bid on his own house and on a rental unit alongside the manufacturer's installation manual, the warranty document, and the code section the line item claims to satisfy. He holds no contractor's licence and inspects nothing. This site is a record of documents compared against each other, not advice on how the work should be done.

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How this is checked

Every guide cites the agency, statute, or document it was checked against, and carries the date it was checked. Rules change — if something here is out of date, tell us and it gets corrected.