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How long does commercial air conditioning last?

Updated 23 October 2026 · SEO Dons Editorial

Is there an official lifespan for commercial air conditioning?

No single figure applies to every system. The recognised source is CIBSE. Its 2026 Economic Life Expectancy Tables, which replace the January 2020 Guide M appendix, "provide Reference Service Life (RSL) values for all building engineering services assets". CIBSE describes the values as "in years (as the indicative economic life expectancy)".

They are a starting point. CIBSE says "Variation factors are adjustment multipliers applied to the reference service life to calculate the economic life based on actual installation". The tables themselves are published as downloads (Guide M11, Appendix 11.A1), not as a web page, so this page does not reproduce them. Ask whoever is assessing a system which table row and which adjustments they used.

What have CIBSE publications said about particular systems?

System or partWhat was publishedWhere, and when
VRF"Most VRF/V systems are currently specified to operate for up to 15 years. However, many still operate efficiently beyond this."CIBSE Journal module 81, September 2015
VRF"With regular maintenance, VRF systems can operate for 15 years or more"CIBSE Journal module 253, October 2025
Water chillers15 to 25 years, depending on air or water cooling and the environmentCIBSE Journal module 112, June 2017, citing Guide M
Scroll compressors in heat pump air handling units"typically achieving 15-20 years of service"CIBSE Journal module 259, December 2025
Splits, air handling units, fan coil unitsNo figure found on a public CIBSE web pageCheck the Guide M11 table

These are dated statements, not promises about any machine, and the chiller figure comes from an earlier edition of Guide M. For chillers in more depth see chiller maintenance and lifespan.

What shortens or extends the life of the plant?

  • Maintenance. The 2025 CIBSE Journal module makes the VRF figure conditional on regular maintenance, and adds that "efficiency can decline over time, parts can become difficult to source, and failures can cause rooms to be taken out of service".
  • Environment and duty. The chiller figure depends on "the environment within which they operate", and CIBSE adjusts reference lives for "specific installation and operational conditions". Ask about hours of use, dust, salt air and traffic fumes at the site.
  • Parts and support. Ask the maker how long parts for the model will be supported, in writing.
  • Leaks and repairs. A system that keeps losing refrigerant is telling you something, and the records show it (see below).
  • Refrigerant availability. Often the deciding factor, covered next.

How does the refrigerant position decide when to replace?

R22. CIBSE Journal says "Hydrochlorofluorocarbons (HCFCs) – such as R22 refrigerant and certain aerosol propellants – have already been banned", and that "any reduction in charge as a result of leakage or major component change will render them inoperable". GOV.UK says "You must not use ODS in new equipment or to service existing equipment" except recycled halons, and that "You can still use equipment that contains ODS as long as it is not leaking". Such a system has no tolerance for a leak. The repair-or-replace question is covered in compressor replacement.

R410A. CIBSE Journal says "there is no immediate ban on R410A in existing systems". But GOV.UK says "The UK is phasing down HFCs by 79% by 2030", and advises that anyone who uses or services HFC equipment should "ask your supplier for advice on alternatives". The current position is in GB F-gas rules in 2026-27.

The cost of switching. CIBSE adds that where a replacement uses a different refrigerant classification, such as a move from a non-flammable gas to R32, "it will be necessary to replace both indoor and outdoor units and the existing pipework". The refrigerant decides the scope of the work as well as its timing. The air conditioning replacement guide covers that side.

How do you plan replacement before a failure?

Build a file of evidence rather than relying on age. Useful items:

  1. F-gas records. Operators must record "the quantities of fluorinated greenhouse gases added during installation, maintenance or servicing or due to leakage" and keep them for at least five years. Repeated top-ups are the clearest warning sign (see refrigerant leaks).
  2. The TM44 report. Systems above 12kW "must be regularly inspected by an energy assessor", at most five years apart. GOV.UK says the assessor will highlight "opportunities to replace older, less energy efficient systems", and may advise where refrigerants are being phased out (see TM44 inspections).
  3. Service and fault history, including parts that are hard to source.
  4. Energy use against the original design performance.
  5. The CIBSE reference life, adjusted for the site.

Then agree triggers in advance. Examples, not standards: a second leak repair within a year, a maker's notice that parts are no longer supported, or failure of a major component on plant already past its reference life. A system on R22 should already have a replacement line in the budget, and the replacement guide covers phasing it. Readers can send an enquiry through the site's form.

Sources

Common questions

Does a warranty tell me how long a system will last?

No. A warranty states what is covered and for how long, which is different from expected life. Read what it excludes, such as refrigerant and consumables, alongside the service record.

How long do fan coil units last?

No figure could be confirmed on a public CIBSE web page, so none is given here. CIBSE's Guide M11 tables list reference service lives by asset. Ask the surveyor which row was used and what adjustments were made for hours of use and environment.

Can an R410A system be kept running while it is sound?

CIBSE Journal says there is no immediate ban on R410A in existing systems. GOV.UK says the UK is phasing down HFCs by 79% by 2030, so ask your service contractor about supply and alternatives, and keep leak checks and records up to date.

Does a TM44 report say when to replace a system?

It can point towards it. The guidance says the energy assessor will highlight opportunities to replace older, less energy efficient systems, and may advise on options for systems using refrigerants being phased out. It is advice, not a replacement date.

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