Uniformat D3040

Exhaust fan

Also called EF, roof exhaust fan

• Confidence C
• Version 0.1.0
• Reviewed 2026-10-21

Service life

Years in service. The band runs from the shortest to the longest life the sources state, so it shows how much they disagree, not how long 80% of units last. The line is the median of the stated lives.

Basis

• 20 years · CNA e-Tool Estimated Useful Life Table, p12 · HUD CNA 3.4.2.2.12 “Central exhaust fans/blowers” — U.S. Department of Housing and Urban Development (planning life)
  Same life for family and elderly properties. US multifamily housing.
• 15 years · Energy Conservation Program: Energy Conservation Standards for Fans and Blowers (notice of proposed rulemaking), 89 FR 3714, January 19, 2024, p75 · IV.F.6 “Equipment Lifetime: GFBs, "15 years in the commercial sector based on the expected lifetimes of HVAC equipment"” — U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy (planning life)
  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.

How sources are chosen and recorded: sourcing policy.

Preventive maintenance

8 tasks in 3 work orders. Intervals that fall due together are one visit: the annual visit also covers the monthly tasks.

1. 1Monthly
2. 2Monthly
3. 3Monthly
4. 4Monthly
5. 5Monthly
6. 6Monthly
7. 7Monthly
8. 8Monthly
9. 9Monthly
10. 10Monthly
11. 11Monthly
12. 12Annual

Months from the schedule start. Daily and weekly rounds run in between. Download the tasks as CSV for a CMMS, or ask the MCP tool get_pm_schedule for dated visits.

Frequencies are ISO 8601 durations in the data (P3M = every 3 months).

Open questions

• Every source here is a published planning, design or accounting life. None is observed replacement data.

Know the answer? Send it with a source to [email protected].

Cite this

Citation

unfinished.one (2026). Exhaust fan, v0.1.0. https://unfinished.one/c/exhaust-fan/v/0.1.0

BibTeX

@misc{unfinished_exhaust_fan_0_1_0,
  title = {Exhaust fan},
  author = {{unfinished.one}},
  year = {2026},
  version = {0.1.0},
  url = {https://unfinished.one/c/exhaust-fan/v/0.1.0},
  note = {CC BY 4.0}
}

Licence CC BY 4.0 · How to cite · JSON · Versions: 0.1.0