Industry Standards for Mean Time Between Failure (MTBF)

Your Q is like shooting an arrow in dark expecting that it will hit some target! Collect data and define a standard for other o follow. All the best.

Object of maintainability is to design & develop systems and equipment which can be maintained in the least time,at the least cost,with a minimum expenditure of engineering support resources ,without adversely affecting the item performance or safety characteristics.MTBF is the mean time between successive failures.It is a useful measure of reliability but it is not correct measure for all applications. Centrifugal chiller is also air cooled liquid chiller. Major parts are compressor,condenser,evaporator,expansion valve and refrigerant and water piping,pumps etc. You can refer ARI standards.

To the best of my knowledge, there is no 'industry standard' for MTBF for the SYSTEMS you reference.

Each component of each system must be evaluated and the failure rate of each component summed, and then the maintenance program must be considered. Developing the failure rate of complex systems is not easy, and a tremendous amount of data from years of consistent operation and maintenance is necessary.

The first place to start is with the manufacturer/vendor of the system and each component thereof.

Major components such as reciprocating compressors may be very reliable with decades of operation without failure--so long as the proper lube oil is renewed when needed. I personally know of one reciprocating hydrogen compressor, 3 stage, 450-3300 psig, synchronous motor drive, that was still operating flawlessly after more than 50 years of continuous operation, with only routine lube oil and filter changes--no other maintenance ever. I also know of others that had MTBF of less than 500 hours in nearly identical service. DETAILS are important.

Residential air conditioning systems routinely go years between malfunctions if properly installed with appropriate protection from electrical supply interruptions. Commercial building HVAC systems are equally reliable provided periodic preventative maintenance is performed. Large scale (100,000KW) mixed gas, multi-machine industrial cryogenic refrigeration systems routinely operate 50,000 hours or more between shutdowns for routine inspection, and are often returned to service with replacement only of lube oils and consumable filters and gaskets.

In summary, the expected MTBF for 'chillers' is not a single number. The range of values is at least 3 orders of magnitude and highly dependent on the particulars of the system, service conditions, and quality of preventative maintenance.

Air operated control valves may work reliably for decades if the motive air is clean and oil-free, but fail in weeks after a single 8 hour shift of oily air caused by failure of the instrument air drier.

Thank you very much for the information. It is quite insightful and parallels what I believed to be true. Are you familiar with any of the available software that is available that is suppposed to help you evaluate the projected MTBF for these types of systems? If so, is there any that you would recommend over the others?

Yep. The manufacturers of <...air-cooled liquid chillers and centrifugal chillers...> will have this information, as might their customers.

It might be commercially sensitive, though, and withheld to give each manufacturer an edge over its competition. Therefore one is unlikely to find it published on the internet.

I don't think there is any published standard, there is however an industry excepted average....

..."On average, an air-cooled chiller's lifespan is anywhere from 15 years to 20 years. A water-cooled chiller is normally closer to 20 to 30 years."...

Of course environmental conditions and maintenance both play a role, and should be considered...

https://agservicestx.com/increase-air-cooled-chiller-life-expectancy/#:~:text=On%20average%2C%20an%20air%2Dcooled,15%20years%20to%2020%20years.

excepted ..accepted...