When Selecting HVAC Products, Look at Part Load Performance
January 8, 2009 - Contact FacilitiesNet Editorial Staff »
I'm Ed Sullivan, editor of Building Operating Management magazine. Today's topic is the importance of the part-load performance of HVAC systems.
HVAC systems are designed to handle extreme conditions. Components of the system are sized for the hottest and coldest days of the year. On those days, the chiller or boiler is running at full load and at maximum efficiency.
But for the rest of the year, the system is running at part load. And in the past that has meant a sharp drop off in energy efficiency.
Today, that needn't be the case. Variable frequency drives, for example, can bring significant improvements in the part load performance of chillers. On the heating side, consider modulating boilers to achieve the same goal.
When you're evaluating HVAC equipment, determine how often your system will be running under part-load conditions. And if that will be a frequent occurrence, look for a system that will be efficient at the part-load conditions that it will actually be facing.