Retrocommissioning Can Solve Three Common Controls Problems
November 1, 2010 - Contact FacilitiesNet Editorial Staff »
Today's topic is retrocommissioning.
Controls that weren't properly designed or programmed, or that have been overridden or otherwise gotten out of whack, can increase energy costs while making building occupants uncomfortable and shortening the life of equipment.
Most of the issues that retrocommissioning identifies have to do with controls, say experts. Perhaps the most common problem is scheduling. Often equipment is running more than it needs to. A pump, for example, may be running longer than it should to satisfy building demand - possibly even all day and night — without anyone knowing it. Not a glamorous problem, perhaps, but it's expensive. The pump will wear out sooner than it should; meanwhile, energy dollars will be wasted.
A second big category of problems has to do with economizer dampers. They may be stuck in one position or there may be errors connected with the control sequences or the sizing of dampers.
Setpoints - supply air temperature and pressure as well as condenser and chiller water temperature - are a third common opportunity for improvement. Retrocommissioning can tune those setpoints to match demand more closely. Retrocommissioning — or recommissioning, if the building was commissioned in the past — is especially important in multitenant buildings and other facilities that undergo a significant amount of change.