{"id":"condensing-unit","version":"0.5.0","classification":{"uniformat":"D3030"},"names":["Condensing unit, split system"],"aliases":["CU","condensing unit","split AC outdoor unit"],"service_life":{"median_years":18.1,"range_years":[15,21.2],"range_basis":"source_spread"},"pm_tasks":[{"task":"Remove debris from air screen and clean under unit","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":443,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Pressure wash condenser coil with coil cleaner and rinse","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Straighten coil fins with a fin comb","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Check electrical connections for tightness","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Check unit mounts and refrigerant line supports","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Clean and treat rusted areas; touch up paint","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Leak test refrigerant circuit","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Check refrigerant charge","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Inspect disconnect switches and contactors for arcing or overheating","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Check compressor crankcase heater","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Check condenser fan blades for dirt and wear","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"},{"task":"Run unit with gauges; check compressor, controls and refrigerant pressures","frequency":"P1Y","reference":"Public Buildings Service Preventive Maintenance Guide (Public Buildings Maintenance Standards)","url":"https://web.archive.org/web/20231003141600/https://origin-www.gsa.gov/system/files/GSA%20PBS%20Preventive%20Maintenance%20Guide%202022-01302023_0.pdf","page":444,"checklist":"HVAC-CND-01-01Y Condensing Unit - Refrigeration"}],"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 3.4.3.1.2","label":"Electric AC condenser, pad or rooftop","years":15,"note":"Same life for family and elderly properties. US multifamily housing."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Residential Central Air Conditioners and Heat Pumps (direct final rule), 82 FR 1786, January 6, 2017","by":"U.S. Department of Energy","url":"https://www.govinfo.gov/content/pkg/FR-2017-01-06/pdf/2016-29992.pdf","page":34,"code":"Table IV-16","label":"TABLE IV–16—AVERAGE LIFETIME BY REGION: Central Air Conditioners, National 21.2 (North 24.1, Hot-humid 18.0, Hot-dry 24.9)","years":21.2,"note":"Printed page 1819. Residential central air conditioners (<65,000 Btu/h), product class group covering split-system and single-package units; mapped to condensing-unit because split-system ACs (outdoor condensing unit + indoor coil) are the bulk of the class and Table V-2 (p.47, printed 1832) gives the same regional lifetimes for split-system central air conditioners. Value is for the whole split system, not the outdoor unit alone. National value used; regional range 18.0 (hot-humid) to 24.9 (hot-dry). Commercial split condensing units >=65,000 Btu/h not covered."}],"confidence":{"grade":"C","sample_size":null},"open_questions":["Every source here is a published planning, design or accounting life. None is observed replacement data.","Written for GSA contracted O&M in US federal buildings; job plans are generic and defer to manufacturer instructions, and the fire extinguisher plans only point to NFPA 10."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-22","canonical_url":"https://unfinished.one/c/condensing-unit","versioned_url":"https://unfinished.one/c/condensing-unit/v/0.5.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Condensing unit, split system, v0.5.0. https://unfinished.one/c/condensing-unit/v/0.5.0"}