Generally speaking, the best candidates for VRF technology will be either older, inefficient buildings due for retrofit, or facilities that have multiple spaces with independent occupancy, varying comfort requirements, and enclosed rooms.
VRF offered a solution for a unique problem at a Chicago office, says Maureen Kozel, senior associate with ESD. An electronic trading firm occupied 13,000 square feet on the 27th floor of the 35-story high-rise built in 1971.
“There was a much higher computer heat load than a typical office, and the firm had just acquired another company, so they increased their headcount and wanted to change the layout,” Kozel explains. “They needed to provide supplemental cooling without altering the walls or the ceilings. By running small pipes to ductless cassettes that just popped into ceiling tiles, VRF was the noninvasive answer.”
At the Manhattan office project, VRF allowed floor-to-floor heights to remain the same in areas where there were only 6 inches between the beam and ceiling. “Any efficiency gain on top of the space savings is icing on the cake,” Franceschini says.
Rush Health Systems implemented a VRF system for the maternity ward on the 45,555-square-foot third floor of the Rush Foundation Hospital in Meridian, MS.
“There was nothing but problems – people being too hot or cold. I had a 34-year-old, 500-ton chiller running at 98% capacity,” says Fred Rogers, vice president and chief resource officer at the hospital.
The site uses VRF for the third floor in conjunction with the old chiller, which still serves the rest of the hospital. The system improved efficiency by taking the entire third floor’s load off the overworked chiller.
“We’ve saved about $36,000 per year in energy reduction just from that one job on the one floor,” Rogers says, adding that he has already installed smaller units throughout the rest of the campus. Two critical access, 25-bed hospitals were recently built and 75-80% of the new facilities are served by VRF, he estimates.