{"id":"exhaust-fan","version":"0.2.0","classification":{"uniformat":"D3040"},"names":["Exhaust fan"],"aliases":["EF","roof exhaust fan"],"service_life":{"median_years":15.5,"range_years":[10,20],"range_basis":"source_spread"},"pm_tasks":[{"task":"Shut down or re-sequence equipment that is not needed","frequency":"P1D","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Do an overall visual inspection: all equipment operating and safety systems in place","frequency":"P1D","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Check belt tension and alignment","frequency":"P1M","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Inspect pulleys; clean and lubricate as needed","frequency":"P1M","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Check dampers close fully; outside air dampers airtight when closed","frequency":"P1M","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Check actuator and linkage operation; clean, lubricate, adjust","frequency":"P1M","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Check fan blades rotate correctly; clean when needed","frequency":"P1M","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"},{"task":"Check electrical connections are tight","frequency":"P1Y","reference":"Operations & Maintenance Best Practices: A Guide to Achieving Operational Efficiency, Release 3.0","url":"https://www.energy.gov/sites/default/files/2020/04/f74/omguide_complete_w-eo-disclaimer.pdf","page":218,"checklist":"9.8.11 Fans Checklist"}],"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 3.4.2.2.12","label":"Central exhaust fans/blowers","years":20,"note":"Same life for family and elderly properties. US multifamily housing."},{"type":"public_document","life_type":"design","title":"Design standards: employer's requirements – Technical Manual (ER-DFE-XX-XX-T-X-0201, revision A-C01)","by":"Department for Education (England)","url":"https://assets.publishing.service.gov.uk/media/6971f649d8adeaf266040501/ER-DFE-XX-XX-T-X-0201-Technical_Manual-A-C01.pdf","page":256,"code":"5.6.4","label":"Air handling units (AHUs), room-based ventilation units, extract fans and controls: 20 years","years":20,"note":"Printed page 256. AHUs, room-based (heat recovery) ventilation units and extract fans; supply/return fans in AHUs included. Minimum life expectancy (design requirement) for DfE-funded school buildings. Minimum design requirements placed on contractors for school buildings, not observed replacement ages. Section 5.1.4 (sanitaryware) refers to CIBSE Guide M Appendix 12.A1 'in general'."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Fans and Blowers (notice of proposed rulemaking), 89 FR 3714, January 19, 2024","by":"U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy","url":"https://www.govinfo.gov/content/pkg/FR-2024-01-19/pdf/2023-28976.pdf","page":75,"code":"IV.F.6","label":"Equipment Lifetime: GFBs, \"15 years in the commercial sector based on the expected lifetimes of HVAC equipment\"","years":15,"note":"Printed page 3788. Commercial-sector lifetime for general fans and blowers (all fan types). Proposed rule; the 15 years is borrowed from HVAC equipment lifetimes, not fan data."},{"type":"public_document","life_type":"accounting","title":"General depreciation rates (IR265), July 2021","by":"Inland Revenue (Te Tari Taake), New Zealand","url":"https://www.ird.govt.nz/-/media/project/ir/home/documents/forms-and-guides/ir200---ir299/ir265/ir265-2021.pdf","page":44,"code":"BDFO","label":"Ventilating fans","years":10,"note":"Printed page 44. Ventilating fans, not ducted or roof-mounted (e.g. wall or window fans). BDFO Building fit-out (when in books separately from building cost). Printed DV 20%, SL 13.5%. Tax depreciation lives set by the Commissioner of Inland Revenue for New Zealand income tax, not engineering or asset-management lives; they are banded and often short (e.g. reticulation piping 25 years). The July 2021 edition was the newest PDF reachable; the online Depreciation Rate Finder may hold later determinations."},{"type":"public_document","life_type":"accounting","title":"General depreciation rates (IR265), July 2021","by":"Inland Revenue (Te Tari Taake), New Zealand","url":"https://www.ird.govt.nz/-/media/project/ir/home/documents/forms-and-guides/ir200---ir299/ir265/ir265-2021.pdf","page":44,"code":"BDFO","label":"Ventilating fans (ducted)","years":15.5,"note":"Printed page 44. Ducted ventilating fans, supply or exhaust. BDFO Building fit-out (when in books separately from building cost). Printed DV 13%, SL 8.5%. Tax depreciation lives set by the Commissioner of Inland Revenue for New Zealand income tax, not engineering or asset-management lives; they are banded and often short (e.g. reticulation piping 25 years). The July 2021 edition was the newest PDF reachable; the online Depreciation Rate Finder may hold later determinations."},{"type":"public_document","life_type":"accounting","title":"General depreciation rates (IR265), July 2021","by":"Inland Revenue (Te Tari Taake), New Zealand","url":"https://www.ird.govt.nz/-/media/project/ir/home/documents/forms-and-guides/ir200---ir299/ir265/ir265-2021.pdf","page":44,"code":"BDFO","label":"Ventilating fans (roof mounted)","years":15.5,"note":"Printed page 44. Roof-mounted ventilating fans. BDFO Building fit-out (when in books separately from building cost). Printed DV 13%, SL 8.5%. Tax depreciation lives set by the Commissioner of Inland Revenue for New Zealand income tax, not engineering or asset-management lives; they are banded and often short (e.g. reticulation piping 25 years). The July 2021 edition was the newest PDF reachable; the online Depreciation Rate Finder may hold later determinations."},{"type":"public_document","life_type":"planning","title":"Future Buildings Standard: final stage impact assessment (RPC-MHCLG-25104-IA), 24 March 2026","by":"Ministry of Housing, Communities and Local Government (UK)","url":"https://assets.publishing.service.gov.uk/media/69c16a6113101e9908704acb/Future_Buildings_Standard_Impact_Assessment.pdf","page":77,"code":"Appendix B","label":"\"20 years for light fittings and ventilation equipment\"","years":20,"note":"Printed page 77. One value for two groups. Light fittings in new buildings are LED (the IA applies LED cost learning). 'Ventilation equipment' is generic; mapped to the ventilation component types it clearly includes. Assumption for new non-domestic buildings in England; the IA says the lifetimes are in line with BS EN 15459 (Annex/Appendix E), but they are stated as the department's own modelling assumptions, not a reproduced table. Round-number economic-appraisal assumptions, not observed lives. Same values as the January 2021 Future Buildings Standard consultation IA (separate file), so the two are not independent."}],"confidence":{"grade":"C","sample_size":null},"open_questions":["Every source here is a published planning, design or accounting life. None is observed replacement data."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-22","canonical_url":"https://unfinished.one/c/exhaust-fan","versioned_url":"https://unfinished.one/c/exhaust-fan/v/0.2.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Exhaust fan, v0.2.0. https://unfinished.one/c/exhaust-fan/v/0.2.0"}