{"id":"gas-detection","version":"0.1.0","classification":{"uniformat":"D3060"},"names":["Gas detection system"],"aliases":["CO detector","NO2 detection","refrigerant leak detector","gas detector"],"service_life":{"median_years":10,"range_years":[10,15],"range_basis":"source_spread"},"pm_tasks":[],"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":310,"code":"5.9.4","label":"Gas sensors and detectors: 15 years","years":15,"note":"Printed page 310. Fuel installations section. 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":"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":48,"code":"FACT","label":"Gas detectors (fixed) - applies from the 2015 and subsequent income years","years":10,"note":"Printed page 48. Fixed gas detectors. Same life under REFR p.52, SCIA p.53 and WATR p.57. 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":52,"code":"REFR","label":"Gas detectors (fixed) - applies from the 2015 and subsequent income years","years":10,"note":"Printed page 52. Fixed (refrigerant) gas detectors. Refrigeration category. 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."}],"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":"2026-10-22","canonical_url":"https://unfinished.one/c/gas-detection","versioned_url":"https://unfinished.one/c/gas-detection/v/0.1.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Gas detection system, v0.1.0. https://unfinished.one/c/gas-detection/v/0.1.0"}