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Methodology for Furnace Research and Directory Profiles

How Furnace System Guide sources claims, handles unknowns, dates its verification, and checks installer directory profiles before publication.

Source standards

Claims are drawn from primary manufacturer spec sheets, AHRI certification records, and energy authorities before publication.

No invented values

AFUE ratings, BTU outputs, stages, and prices are left unknown until a source confirms them.

Directory firewall

Payment for a directory listing never changes a profile's verification status, its ordering, or the evidence boundary applied to every provider.