{"id":"furnace-gas","version":"0.3.0","classification":{"uniformat":"D3020"},"names":["Furnace, gas-fired"],"aliases":["furnace","forced air furnace","gas furnace"],"service_life":{"median_years":20,"range_years":[15,25],"range_basis":"source_spread"},"pm_tasks":[],"basis":[{"type":"public_document","life_type":"planning","title":"CNA e-Tool Estimated Useful Life Table","by":"U.S. Department of Housing and Urban Development","url":"https://www.hud.gov/sites/documents/eul_for_cna_e_tool.pdf","page":12,"code":"HUD CNA 3.4.3.1.4","label":"Gas furnace/air handler","years":20,"note":"Same life for family and elderly properties. US multifamily housing. The municipal rows say furnace without naming the fuel."},{"type":"public_document","life_type":"accounting","title":"The Blue Mountains: POL.COR.19.04 Tangible Capital Assets Policy","url":"https://www.thebluemountains.ca/sites/default/files/2022-01/POL-COR-19-04-Tangible-Capital-Assets-Policy.pdf","page":11,"label":"Furnace","years":15,"note":"Capital asset policy (amortization period). Approved on text check: the label and value were found on the cited page."},{"type":"public_document","life_type":"accounting","title":"Grey Highlands: By-law No. 2026-052, Tangible Capital Asset Policy A09-F-03","url":"https://greyhighlands.civicweb.net/document/406218/","page":11,"label":"Furnace","years":15,"note":"Capital asset policy (amortization period). Approved on text check: the label and value were found on the cited page."},{"type":"public_document","life_type":"accounting","title":"Meaford: By-law 2020-83, Tangible Capital Asset Policy, Appendix A Estimated Useful Lives","url":"https://meaford.civicweb.net/document/103944/","page":17,"label":"HVAC - Furnace","years":[15,25],"note":"Capital asset policy (amortization period). Approved on text check: the label and value were found on the cited page."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program for Certain Industrial Equipment: Energy Conservation Standards for Small, Large, and Very Large Air-Cooled Commercial Package Air Conditioning and Heating Equipment and Commercial Warm Air Furnaces (direct final rule), 81 FR 2420, January 15, 2016","by":"U.S. Department of Energy","url":"https://www.govinfo.gov/content/pkg/FR-2016-01-15/pdf/2015-33067.pdf","page":4,"label":"\"the average lifetime of the equipment, which is estimated to be 23 years for both gas-fired and oil-fired CWAFs\"","years":23,"note":"Printed page 2423. class: commercial warm air furnaces >=225,000 Btu/h input, gas-fired and oil-fired. Commercial, mostly weatherized/rooftop-mounted; residential furnaces are covered separately (consumer furnace rule). Lifetime derived from the CUAC lifetime (section IV.F.6.b, p.60, printed 2479)."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Consumer Furnaces (final rule), 88 FR 87502, December 18, 2023","by":"U.S. Department of Energy","url":"https://www.govinfo.gov/content/pkg/FR-2023-12-18/pdf/2023-25514.pdf","page":70,"code":"IV.F.6","label":"\"DOE estimates the average product lifetime to be 21.5 years for NWGFs and MHGFs\"","years":21.5,"note":"Printed page 87571. residential: non-weatherized gas furnaces and mobile home gas furnaces; national average. Regional averages 22.5 years (North) and 20.2 years (rest of country) in the same paragraph. Also p.2 (printed 87503)."}],"confidence":{"grade":"C","sample_size":null},"open_questions":["Every source here is a published planning, design or accounting life. None is observed replacement data.","No preventive maintenance tasks are sourced yet."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-21","canonical_url":"https://unfinished.one/c/furnace-gas","versioned_url":"https://unfinished.one/c/furnace-gas/v/0.3.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Furnace, gas-fired, v0.3.0. https://unfinished.one/c/furnace-gas/v/0.3.0"}