{"id":"ahu-indoor","version":"0.1.0","classification":{"uniformat":"D3040"},"names":["Air handling unit, indoor"],"aliases":["AHU","air handler","air handling unit"],"service_life":{"median_years":20,"range_years":[20,20],"range_basis":"source_spread"},"pm_tasks":[{"task":"Check filters for gaps; replace when dirty","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 for moisture or growth on surfaces and ducts; check odours and complaints","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 ductwork; refasten loose connections and repair leaks","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"},{"task":"Coils: confirm filters have been kept clean","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"},{"task":"Inspect and repair or replace damaged duct insulation","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":"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":"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/ahu-indoor","versioned_url":"https://unfinished.one/c/ahu-indoor/v/0.1.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Air handling unit, indoor, v0.1.0. https://unfinished.one/c/ahu-indoor/v/0.1.0"}