Aug 1, 2014

Final Report: Advanced Rooftop HVAC Unit Controls Pilot

Richard Szyldlowski


A number of new products on the market claim to deliver energy savings to existing roof top air handling systems. The Center for Energy and Environment wanted to field test these products and their manufacturer’s claims of savings in a climate that is not predominately cooling, such as Minnesota’s. The roof top unit (RTU) market is estimated at 46 percent of all commercial spaces in Minnesota (EIA, 2003), which includes offices, manufacturing, warehousing, and other box-type properties. Despite RTUs market share, very few options can improve their efficiency. The construction industry uses RTUs to lessen initial development costs without considering the long-term operational costs for the owner or tenant. These new energy-saving products could improve the inherently low performance of standard roof top systems and achieve significant savings for the building operator/owner or tenant.

The research team proposed to study the potential of advance control optimizers to save money in Minnesota’s climate. This research was funded by the Minnesota Department of Commerce, Division of Energy Resources, Conservation and Applied Research Development Grant program. This pilot evaluated three optimizers which demonstrated sufficient product maturity and market readiness to be tested in a pilot research project: Catalyst, Digi-RTU, and Premium Ventilation.