The art and science of how to gauge an HVAC replacement initiative is the subject of a Facilities.net piece posted this month.
An organization can wait until a system breaks down or move earlier. A “run to failure” approach has to be considered in the context of whether that eventual failure will result in losses (such as the being temporarily closed) or if the backup systems that are put in place to take over when systems go offline are prohibitively expensive.
This all fits into a sophisticated life-cycle cost analysis. This goes far beyond simply estimating the payback period, which is more appropriate with small and isolated pieces of equipment, the story says:
A life-cycle cost analysis will include upfront costs, operating costs, maintenance costs, special costs, and end of life disposal costs.
The bottom line is that deciding when to replace mission-critical systems and/or how to prepare for their inevitable failure, is a very complex issue. Last week, Energy Manager Today blogged about the failure of the cooling towers at the Northport Veterans Affairs Medical Center in Northport, NY. Nothing is as mission-critical as the equipment that houses and treats wounded veterans. When the system went off line, a temporary installation was made within 48 hours and, eventually a permanent replacement plan executed. That job, which is slated to be finished in June, featured the rather dramatic placement of cooling towers by a Sikorsky helicopter.
A helpful tool is available from The Hydronics Industry Alliance. The Commercial (HIA-C) Building Efficiency System Tool features Building Efficiency Ratings (BEER) is based on annual energy consumption and life cycle cost comparisons for building HVAC systems, the organization says.