One of the worst things you can do is note the capacity and replace the chiller. Have the building loads and usage changed? What about motors and cooling towers? Consider these and your part-load realities to create real long-term improvements.
The replacement of chillers for hospitals and other health care facilities are often done out of absolute necessity, and it is often avoided for as long as possible. The chillers in health care facilities are usually the most expensive piece of equipment in HVAC system. The removal and replacement of chillers can be very disruptive, often requiring modification to the chilled water and condenser water piping system, and, in a lot of cases, the removal of walls and ceilings. Most hospitals have multiple chillers that are manifold together to serve the connected building load. Smaller outpatient facilities usually consist of one chiller serving the entire building. The replacement of chillers in any building is usually a time-consuming process requiring detailed planning long before the equipment is actually replaced.
Because of these factors, building owners and maintenance staff move very cautiously when faced with potential replacement decisions, simply keeping the chillers in place as long as it keeps operating. While such an approach may make sense for office buildings and other commercial buildings, this can create unsustainable situations for HVAC maintenance — with the most extreme outcome being chiller failure, which could leave the facility without cooling for an extended period of time.