When it was built in the early 1970s, the 13-story Loretto Nursing Home was equipped with two, one-million BTU/hr. gas-fired Lochinvar heaters and two, 2,000 gallon storage tanks to meet the Syracuse, New York facility's domestic hot water needs. In response to a middle-of-the-night brainstorm by the home's HVAC service contractor, Falso Service Experts, this infrastructure was replaced by five, one-million BTU/hr. AERCO high-efficiency heaters in a tankless DHW solution. As a result of the change, the nursing home cut its fuel usage nearly in half and saved almost $17,000 in costs during the first four months of operation.
In early 2007, Tony Stevens, of Falso Service Experts, was troubleshooting a valve problem unrelated to Loretto's DHW system. After wrestling with the difficult-to-diagnose problem, he was struck by the fact that the water heaters in the mechanical room never stopped running during the entire length of the service call. Although it was the middle of the night with no DHW demand, the heaters were operating continuously just to maintain the temperature in the storage tanks.
"I knew right away that the right tankless system would save these guys a fortune," said Stevens.
A design/build contractor, Stevens suggested his client replace the existing system with a tankless DHW design using high-efficiency AERCO water heaters. After providing a payback analysis to Loretto, Stevens tore out the storage tanks and installed five, one million BTU/hr., condensing KC1000 water heaters. Among the benefits of the KC units were an increase in operating efficiency of the system and elimination of the storage tanks to reduce the risk of Legionella - another important benefit of a tankless system.
Even though the total capacity of the heating plant increased from two million BTU/hr. to five million BTU/hr., energy expenses were dramatically reduced. From July through November of 2006, the facility used 40,753 therms at a delivered cost of $40,143. In contrast to the same period in 2007, the facility used just 23,670 therms at a delivered cost of $23, 327. The combination of condensing operation and 20:1 turndown cut therms by 42% and saved $16,816.
Each modulating KC1000 heater can match any load from 50,000 BTU/hr. to 5 million BTU/hr. without wasteful cycling. Their ability to modulate in a matter of seconds in the face of rapidly changing DHW loads ensures tight temperature control for Loretto's residents.
Falso Service Experts has teamed up with Loretto to review all its buildings' domestic and hot water heating needs. AERCO boilers and hot waters heaters have also been installed in Loretto's Fahey facility with the same results and its Bernadine Facility is scheduled for January 2008 replacement.