Regional Medical Center Saves $20,000 & Restores HVAC System Performance Through Ultraviolet-C Technology
Kentucky, USA
Download Case Study PDF- 35%
- Airflow increase
- $20,000+
- AHU replacement cost avoided
- 6 weeks
- Trial period
- 30%
- Airflow deficit recovered
The Challenge
Engineers at a 359-bed facility in Kentucky struggled to keep the hospital's cafeteria cool amid the humid climate. Condensate in the air handling unit (AHU) serving the food service area was leaving a residue in the coil — a buildup that reduced airflow through the unit from the 14,000 CFM design parameter to around 10,000 CFM, nearly 30 percent less than originally specified. "The air handler wasn't able to help keep the café and kitchen cool during peak demand, especially during standard meal times in July and August, when occupancy and thermal loads were at their highest," recalls the hospital's Director of Engineering. Maintenance staff tried up to three mechanical coil cleanings per year at roughly $300 per treatment, but the cafeteria AHU remained the worst performer among the medical center's roughly 30 air handlers. The Director was considering replacing it — a task that would cost more than $20,000 and require two to three days of downtime.
“After a mere 90 days, airflow is back to design specs and we are able to maintain the desired temperature set points in the kitchen and cafeteria. The AHU motor is drawing less amps, saving the hospital energy.”
The Solution
A UV-C technology trial was proposed with no financial risk to the hospital: install UV-C lamps in the cafeteria air handler, and if performance didn't improve in six weeks, the hospital wouldn't pay a penny. "Having not tried this technology, we had some skepticism regarding the UV-C energy's ability to improve airflow and heat-exchange efficiency," the Director admits. "It's hard to justify capital investments for equipment that is 20 years old and was earmarked for replacement." UV-C lamps were installed on the downstream, air-exiting side of the coil, where they are most productive killing mold and bacteria and degrading all other organic materials. The UV-C wavelength removes organic growth rather quickly — often in less than one month — without producing any residual matter.
Results
Installation of UV-C fixtures was completed in September 2014. An independent project audit documented a 35 percent increase in airflow — an additional 3,700 CFM, from a baseline of 10,300 CFM back up to 14,192 CFM — restoring the ability to achieve the hospital's cooling set points in the cafeteria. The initial measured pressure drop across the coil of 2.66 inches WG decreased to 0.69 inch WG, meaning the fan was drawing less energy. "After a mere 90 days, airflow is back to design specs and we are able to maintain the desired temperature set points in the kitchen and cafeteria," confirmed the Director of Engineering. "The AHU motor is drawing less amps, saving the hospital energy. Based on this successful demonstration, we've decided to incorporate these performance-enhancing UV-C fixtures in more of the hospital's AHUs." The hospital avoided the $20,000+ AHU replacement entirely. The team planned their first retrofits for the air handlers serving the operating rooms, patient rooms, and radiology department — a total of four additional units.
- 35%
- Airflow increase
- $20,000+
- AHU replacement cost avoided
- 6 weeks
- Trial period
- 30%
- Airflow deficit recovered
- 90 days
- Back to design specs
Your facility could be next.