Boiler Efficiency Upgrade Case Study

Subject Facility:
Sheraton Sand Key Resort, 390 Rooms

Location:
Sand Key Clearwater Beach, Florida

Project Goal:
Investigate Alternative Equipment Solutions in Upgrading Water Heating System Efficiency for Production of Process and Domestic Hot Water.

Summary:
The water heating conversion project focused on replacement fourteen year old low efficiency Raypak atmospheric heaters to new correctly sized high efficiency natural gas fired Thermal Solutions water heating equipment without facility disruption. The turn-key project cost of $101,000.00 resulted in an annual utility reduction in the amount of $24,881.00. The return on investment of 24.6% yielded a simple payback of 4.1 years.

Narrative:
Seaway Properties, contracted with Delta Hydronics, Inc. to provide a financial and mechanical solution to replace the aging and inefficient water heating system with new correctly sized higher efficiency equipment.

Facility Survey:
The survey of the facility’s mechanical processes for the production of domestic hot water for showers, process hot water for laundry and kitchen usage yielded the following:

The original Raypak water heating system was installed utilizing an instantaneous loop design without the use of storage tanks. The absence of storage capacity created a dual problem of insufficient supply temperature for laundry/kitchen operations as well as reduced domestic loop temperatures during peak tourist season. The original design utilized four 1,230,000 BTU Raypak atmospheric water heaters that operated continuously at low fire input resulting in 58% combustion efficiency. The age of existing equipment, inconsistent hot water supply temperatures and high fuel costs resulted in a management decision to employ Delta Hydronics to replace a fully operational water heating system.

Energy Cost Evaluation:
Evaluation of facility’s fuel bills, peak occupancy hot water demands and investigation of alternative equipment efficiencies yielded the following:

The resort’s peak guest occupancy required consumption 11,600,000 BTU/day of natural gas to generate domestic hot water. At a cost of $1.00/100,000 BTU’s and an annual occupancy rate of 85%; the cost of hot water generation using existing 58% efficient equipment averaged $72,986.00 per year.
Redesign and correct sizing of the water heating system using new 88% efficient equipment yields an annual fuel cost of $48,104.00 per year. Project implementation resulted in an annual natural gas savings of $24,881.00 per year

Engineering Analysis:
Delta Hydronics performed hot water demand analysis enabling a 1,140,000 BTU reduction in water heating system input, performed a twenty year life cycle analysis detailing a future cost avoidance of $570,000.00, and provided a comprehensive ROI and fuel savings analysis.

Project Implementation:
To insure non-disruptive project implementation, the installation was performed in phases. Two of the four existing heaters were demolished to enable transition to new equipment while maintaining building hot water supply. All work was performed during low occupancy periods as not to disrupt guest and hotel services.