Case Studies

"We have scheduled a new project to upgrade our AERCO units for dual fuel usage... the ability to switch to propane for emergency back-up is mission-critical to our facility." - John English, director of Plant Operations

Providing heat and hot water to support the Glenwood Regional Medical Center in West Monroe, Louisiana, is a 24/7 operation. For more than 25 years, these essential services at the 366,973 sq. ft. medical facility were driven by four large steam boilers that fed shell-and-tube heat exchangers to support the facility’s hydronic heating loop. These boilers also powered a storage tank water heating system for its domestic water supply. This hulking, inefficient system was overhauled in 2002, and the job of these steam-fired heaters was transferred to 11 AERCO gas-fired units.

“The design of the old boilers was woefully inefficient,” said John English, director of Plant Operations at Glenwood Regional Medical Center. “We were first introduced to AERCO on a visit to the Willis Knighton Medical Facility. After touring that facility’s mechanical room and seeing its low energy cost figures, we realized the advantages inherent with modulating and condensing boilers. We then requested that our consulting engineer, T. Hardy Hays of T. Hardy Hays Consulting Engineers, design a project that capitalized on high-efficiency AERCO units for our facility.”

English installed two AERCO natural gas-fired KC1000 tankless water heaters in the summer of 2002, and three more later that year in November. Two of the 1.0 million BTU/hr. water heaters are now used for kitchen water supply, with two others used for domestic water supply. The remaining unit – utilized as a swing heater – is set for domestic service but can be switched over to the kitchen if backup is needed.

During the November installation, six Benchmark boilers, connected to an AERCO BMS (Boiler Management System), were installed to handle the facility’s space heating load. The BMS regulates operation of the 12.0 million BTU/hr. boiler plant, giving each of the six modulating units precise firing instructions so that maximum energy efficiency is maintained and operating hours are distributed evenly across all boilers.

The Bottom Line

$70,000 in Gas Savings

Expenses at the large medical center have been significantly reduced since AERCO assumed the facility’s total hot water and heating loads. During the last six months, Glenwood Regional Medical Center cut its natural gas consumption by more than 8,055,000 cu. ft. when compared to average consumption over the previous four years.

“With AERCO we realized more than $70,000 in gas cost savings,” English said. “The units basically run themselves. We have scheduled a new project to upgrade our AERCO units for dual fuel usage. While our move away from steam to natural gas was a money-saving decision, the ability to switch to propane for emergency backup is mission-critical to our facility. AERCO is the only high-efficiency boiler that can alternate fuel supplies by simply changing the position of an internal valve.”

	CCF 4 Yr. Avg.	CCF 2003	CCF Savings	CCF Save	Cost/ CCF	Cost Save
Jan	0.144788	0.103471	0.0413171	15162.2500	0.8125	$12,317
Feb	0.131503	0.102926	0.0285772	10487.0636	0.9594	$10,061
Mar	0.131436	0.08311	0.0483267	17734.6045	0.8736	$15,494
Apr	0.105677	0.073251	0.0324267	11899.7270	0.9098	$10,826
May	0.101978	0.06195	0.0400283	14689.3171	0.9166	$13,464
Jun	0.090983	0.06216	0.0288234	10577.4083	0.9066	$9,590
Total				80,550.3701		$71,752

Sq. Ft. = 366,973