Errors in controls — especially for HVAC systems — can cause an array of problems within a facility. Wasted energy is only the starting point. Controls that weren’t properly designed or programmed, or that have been overridden or otherwise gotten out of whack, can make building occupants uncomfortable and shorten the life of equipment.
The way to find and fix those problems is well-established but too rarely used. Retrocommissioning applies the principles of commissioning to existing buildings rather than to new ones. Sudies have shown retrocommissioning to be a cost effective way to improve the performance of controls and to remedy other problems within a building.
Most of the issues that retrocommissioning identifies have to do with controls, says Dave Moser, senior engineer, Portland Energy Conservation Inc. (PECI). “The most common problem is scheduling,” he says. “It’s not a glamorous problem, but we’re finding that 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 to 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.
Retrocommissioning Can Cut Costs by Improving Controls Performance
Benefits of Retrocommissioning Quickly Pay for Costs
