Countless times over the years I have been asked the following question by building managers and consumers: “How long should my equipment last and when should I consider replacing it?” The answer to proper life cycle planning is somewhat complex because there are so many factors which can impact the life expectancy of HVAC equipment. Although by no means complete the list below contains some of the most influential contributors:
- Component Quality
- System Design
- Climate Zone
- Usage Demands
- Voltage Quality
- Technician Competence
Manufacturers have control over very few of these factors so they must assume those over which they have no control will be performed in the manner required if the systems are to achieve expected capacity, comfort levels for occupants and of course full life expectancies. Original equipment manufacturers (OEM’s) can also be referred to as designers and assemblers because many of the most important components used in HVAC systems are provided by vendors who must meet the OEM specifications, one of which is expected life span based on a specific set of benchmark values. Life cycle planning must then be tied to the benchmark values.
Another factor that can be considered is warranty history. Generally speaking residential equipment comes with longer OEM warranties (5 to 10 years) than commercial equipment (typically 1 year) making warranty analysis for life cycle planning more difficult in commercial building because after the first year most OEM’s have no way to track part failures or even unit failures since the part replacement is not logged by serial number.
Most vendors who supply HVAC OEM’s with components, both electronic and mechanical, will tell you they are tasked with providing products with an expected life span under normal usage of 15 years. This is not to say all components and by extension the systems they are installed in will last 15 years, then fail. Many will last longer while some will fail sooner, depending in large part on the list of factors discussed earlier. So the quick answer would be a prudent life cycle planning time is 15 years. Budgeting and planning for replacements after that many years is well worth the effort when compared to the downtime and unhappy occupants in a home or building with no cooling in summer or no heat in winter. No one likes to replace equipment that appears to be running. However replacement costs are more easily controlled when planned in advance as opposed to making decisions while family members, customers and/or employees are hot and sweating or cold and angry about it.
So how can one help ensure you reach the 15 year benchmark? A reasonable recommendation would be to have procedures in place to ensure the items listed above are considered in any new equipment design specification and to insist a commissioning sheet is provided as part of every unit start-up. It’s also recommended that someone be tasked with ensuring proper and regular maintenance is performed on all systems. Nothing is more effective in the long-term than regular maintenance with regard to occupant comfort as well as ensuring full equipment life cycles.
Finally, be careful to not let this 15 year benchmark be the only deciding factor in proactive life cycle planning. Replacing a particular system that has experienced failures for one reason or another may be more cost-effective than sticking to the 15 year rule. Also, life cycle expectations must be adjusted for systems installed in special climates such as those exposed to direct salt spray at the ocean or in other extreme environments like the high ambient conditions found in the desert.
This post was provided by Jack Bartell, Director, Service and Training for Virgina Air Distributors from their Service Tips letter VAST-13-006 Virginia Air Service Tip 08/28/13. Thank You Jack for sharing this information with us.