Chiller Replacement Project
NewYork-Presbyterian Queens’ ( NYP Queens) central chiller plant consists of three 1,100 ton gas fired absorption chillers. To better study equipment performance and chilled water distribution issues, the NYP Queens Engineering department commissioned a performance study of the entire plant through the New York State Energy Research & Development Authority (NYSERDA) FlexTech program. Under the FlexTech program, 50% of the study’s costs were reimbursed. When the need arose to replace a failed unit, this report was used as the basis of design for the replacement chiller. The replacement unit would be a 1,200 ton electric centrifugal chiller. A slightly larger electric unit was preferred based on its higher efficiency and lower operating and maintenance costs as well as the future flexibility of the central chiller plant. This unit is also smaller in size, and as such will fit into the existing footprint.
NYP Queens once again applied for NYSERDA performance based incentives, this time through the Existing Facilities program. A 1,200 ton York YK Max E Chiller was selected. The selected unit qualified for the NYSERDA Super Efficient Electric Chiller Bonus by exceeding standard energy efficiency criteria by at least 2% at full load and by at least 12% at part load. The rebate totaled $87,000 and was received by NYP Queens this fall subsequent to a successful inspection by NYSERDA representatives. When comparing standard performance chillers to the high efficiency units, it was estimated the high efficiency unit would use 17% less electricity and thereby cost $33,000 less per year to operate. The incremental cost for the higher efficiency unit was $180,000 yielding a simple payback of 5.4 years. This payback was further reduced to 2.8 years when the NYSERDA rebate was factored in.
Simple payback for cost of high efficiency chiller
Project Cost $
|York YK Max E Chiller||175,200||88||$33,304||$180,000||5.4|
The new chiller was put on line June 8, 2011 and ran successfully through the cooling season. The switch from a natural gas driven chiller to an electric driven unit obviously resulted in lower natural gas consumption and an increase in electricity consumption. After converting both fuels into carbon equivalents, we can report a reduction in facility carbon emissions attributable to the chiller plant. The new York chiller reduces our annual carbon emissions by 1,655 metric tons. That is equivalent to the annual gas emissions from 325 passenger vehicles, and more importantly it represents a 7% reduction in overall carbon emissions at this facility. NYP Queens is participating in the PlaNYC Mayor’s Challenge where the goal is to reduce carbon emissions by 30% in ten years. The chiller plant upgrades bring NYP Queens’s total carbon emission reductions to 27% from the baseline year.
The new chiller improves the overall production of chilled water and air conditioning throughout the campus. It has also improved the efficiency of the central chiller plant and reduced operating costs. The new unit has been on line for two cooling seasons and has resulted in lower utility costs for the central chiller plant. The savings are achieved through a large reduction in gas use which is replaced by a lesser amount of electricity use in the new chiller as it is more efficient. Maintenance costs dropped by $15,000 per year with the new equipment. The full project cost was $1.9 million dollars and was completed in less than five months, just in time for the 2011 cooling season. The energy rebate and the operational savings will provide the entire project with a simple pay back just over seven years.
Simple payback – complete project
|New Chiller Installation (equipment, A&E, construction)||$1,900,000|
|Annual Energy Savings||$(240,000)|
|Annual Maintenance Savings||$(15,000)|
|Total Annual Savings||$(255,000)|
|Simple Pay Back (years)||7.11|