Hospitals & Universities
This project was redesigned by ROI after initial designs by another firm were rejected by the client. There were actually four projects being implemented – replace the chiller plant, replace the boiler plant, replace half the air handlers, replace the other half of the air handlers.
In the chiller plant, two single effect steam fired absorption chillers were replaced by one variable speed centrifugal and one direct fired absorption chiller, increasing the chiller capacity by 60%.
The boiler plant project consisted of replacing two 35,000 pound per hour 125 PSI boilers with two 14,000 PPH boilers.
The air handler project consisted of replacing every major airhandling unit in the hospital with AHU’s increased in capacity by 65% to 95% to accommodate greater fresh air loads imposed by new standards for IAQ, and to reflect the real ambient conditions experienced at the hospital.
Due to budget considerations, these retrofits took place over a three year period, and were accomplished with zero downtime to the hospital.
The project won an energy conservation award from San Diego Gas & Electric.
This 2,000,000 square foot hospital complex has been undergoing an energy retrofit for the past two years, with an estimated construction cost of $9,000,000. Our energy retrofit project within this larger project has totaled approximately $3,000,000 to date, with the next phase expected to be released in February 2001, with an estimated construction cost of $2,000,000.
The project included the addition of variable speed drives to the majority of the fan systems in the main buildings, the replacement of the corroded cooling coils in the 1,000,000 square foot facility, the upgrade of the economizer systems, the replacement of the variable pitch vane-axial fan systems with fixed pitch hubs and variable speed drives to improve the reliability and energy performance and DDC control system sequences to trim energy waste.
ROI teamed up with a large production engineering house for this project. A 3,200,000 gallon chilled water based TES system was added to the campus, and the piping connections to 32 buildings were modified to coordinate the operations with the TES system.
There had been several additions of chillers to the chiller plant, and the 24″ and 30″ piping within the plant spanned approximately 75 yards. The main 36″ feeds left the plant in two locations, so obtaining a common return point proved to be very interesting. There was quite a “spaghetti-mess” of piping there.
The system reduced operating costs approximately 40% greater than anticipated, and with the recent rate hikes in San Diego, the savings have been even more spectacular.
This is the largest TES system on the SDG&E power Grid.
Approximately 1995, ROI was brought in to assist a large, private University in Southern California in developing an energy and infrastructure master plan. Over 94% of the buildings on campus were served by dedicated chillers, chilled water pumps and cooling towers, or had packaged air cooled equipment to provide HVAC services.
The University management realized that much of their HVAC system infrastructure would need to be replaced within a few years, as equipment failures had become more commonplace, and more catastrophic. Chillers and cooling towers that are 30 to 40 years old are past their useful lives, and are basically energy hogs.
ROI worked with the University Engineering staff, and assisted in evaluating several potential firms to act as the General Contractor for the energy infrastructure and energy procurement projects. Enron Corporation was eventually selected over some very stiff competition.
Enron was retained to implement a new chiller plant and piping infrastructure system to connect to another chiller plant that had been designed previously by ROI, and installed in one corner of the campus.
Enron was given the design package developed by ROI and the University, and retained subcontractors to implement the project. ROI was retained by Enron to commission the project to meet the goals and objectives set forth by the University. Over the last few months of 2000, the chiller plant (chillers, pumps, cooling towers) operated between approximately 0.50 kW per ton and 0.55 kW per ton, but in recent months, we have been able to obtain overall system performance of between 0.42 and 0.48 kW per ton. After the commissioning and training efforts are finalized, the system should be capable of operating at below 0.40 kW per ton during the winter.
This compares to system efficiencies of 1.1 to 2.3 kW per ton for the systems that have been replaced by the new plant.
ROI is continuing our work for the University at the Health Sciences Campus, located approximately 13 miles from the main campus. At the request of the University, Enron has retained ROI to design two new chiller plants at the Health Sciences Campus, one 2725 ton plant and one 700 ton plant. These plants should be capable of year round average kW per ton efficiencies of 0.50 kW per ton (large plant) to 0.55 per ton (smaller plant). The smaller plant has space restrictions that keep ROI from using the most efficient equipment possible.