This hospital's HVAC system previously required that fans ran at 100% every day in order to cool individual rooms, causing the facility to used considerably more electricity than necessary. AC drives were employed to optimize fan and pump performance, which resulted in considerable savings.
Lewis County General Hospital and Residential Health Care Facility in Lowville, NY, is a unique county-owned and operated hospital offering 54 acute care and 160 long-term care beds. Unlike many county-run hospitals, Lewis County General is self-sufficient. It operates on funds generated by utilization of services. Therefore, the hospital administrators are always looking to decrease overall operating costs and find ways of running the facility more efficiently.
Richard Schneider, maintenance supervisor for the hospital, knew the facility's HVAC system was ripe for improvement due to the age and inefficiency of the system; a VAV system that used discharge air dampers.
"We were getting charged for excessive demand by our utility because we would run the HVAC system 24 hours-a-day during the summer," said Schneider. "We knew there were ways to improve the HVAC system's energy efficiency, but we had to find a creative way to pay for it."
A BALANCING ACT
The hospital maintenance staff knew it could lower the amount of energy consumption the system used but needed assurance that patient care and comfort would remain at the highest level. Additionally, any improvements had to be balanced with equal payback in energy savings, meaning energy costs had to be reduced enough to pay for purchasing new equipment.The hospital's HVAC system relied on a closed-loop chiller, which included an on-site cooling tower and frequent air exchanges, as required by the Joint Commission on Accreditation for Health Care Organizations. The closed-loop system used three loops that pumped water through the air handlers and over cooling coils to lower the air temperature. Fans moved the cool air from the air handler through the facility's ventilation system to individual rooms, where climate is controlled by individual thermostats. Because the fans ran at 100% every day, the facility used considerably more electricity than necessary.
Lewis County Hospital installed a computer-based EMS to track temperatures and energy use throughout the facility. The data from the system helped assess where improvements could be made, and the fans moving cool air through the HVAC system were proven to be a prime candidate for upgrades.
"The system showed through carbon dioxide sensors that we didn't necessarily need them to run full ventilation at all times," said Schneider. The hospital now employs two EMS: a Siemens Apogee, and a Trane Tracer Summit, both of which were selected through a bid process.
THE JUSTIFICATION
Schneider worked with electrical distributor Baldwin-Hall in determining how to reduce the amount of energy the fans consumed, and the distributor also found an innovative way of paying for the upgrade."Baldwin-Hall recommended installing Allen-Bradley® PowerFlex® 400 AC drives on the supply and return fans of the air handler to reduce energy consumption," said Schneider. "They also worked with us to determine how we could finance the drives, knowing we had to demonstrate a solid energy payback to justify the purchase." The PowerFlex 400 AC drives are designed to optimize fan and pump performance throughout facilities, which results in lower total costs of building automation.
Schneider said the hospital selected the PowerFlex drives because of the willingness of the company's system integrator to review the pre-existing applications and provide cost savings in addition to a willingness to help with the set-up and installation.
Baldwin-Hall helped Lewis County work with the New York State Energy Research and Development Authority (NYSERDA) to take advantage of the New York Energy Smart rebate program, which is designed to encourage energy efficiency and reduce consumption by offering rebates to utility customers who purchase energy-efficient technology.
"NYSERDA provided a rebate on 50% of the cost of the system," said Schneider. "We were able to reduce our energy costs, as well as help pay for the cost of the upgrade with the rebate, convincing us to move forward on the project."
The total cost to purchase and install the drives on four air handlers in the HVAC system was $32,000, with NYSERDA paying for half of the total cost based on the projected energy savings. The hospital received more good news when it discovered that engineers had underestimated the projected energy savings by nearly 50%.
"We estimated reducing the HVAC system's energy by about 8%," said Scheider. "As it turned out, we reduced costs by about 15%."
The energy savings gave the hospital enough savings to recoup the drives investment in less than six months. "Now we're saving additional dollars on top of the rebate and estimated cost savings. The drives have already paid for themselves and more."
