ACHRNEWS

Carrier Systems Generate Energy Savings

September 8, 2008

ORLANDO, Fla. - The daily cost of doing business is becoming a sizeable burden for small and large business owners alike. The Marriot hotel chain is not exempt from these challenges and with the help of Carrier Corp., it stands to save an estimated $900,000 annually in energy costs. The Orlando World Center Marriot, the largest hotel in the Marriot worldwide chain, is employing Carrier’s commercial cooling towers and variable speed drives in order to achieve these yearly savings.

Carrier’s Building Systems and Services business unit was awarded the hotel’s $1.9 million chiller plant renovation contract, which included replacing three cooling towers and variable speed drives. While initial energy savings estimates were for $310,000 annually, the hotel is currently achieving significantly higher savings. According to Jeffrey Plutz, FMA, RPA, director of engineering and resort facilities at the Orlando World Center Marriott, the hotel saved approximately $225,000 in the first quarter of 2008.

The Orlando World Center Marriott selected Carrier after a thorough assessment of its 23-year-old chiller plant. “We recognized that our existing forced draft cooling towers were inefficient, deteriorating, and undersized for the humid Orlando conditions,” said Plutz. “The condenser water pumps previously required manual priming at startup and the chillers were candidates for an energy-savings retrofit with variable speed drives.”

The three new stainless steel cooling towers have increased the facility’s cooling capacity by approximately 300 nominal tons. Replacing the old cooling towers with new induced-draft style cooling towers reduced the connected electrical load to the cooling tower fans by more than 400 horsepower. The cooling towers and steel support structures were replaced individually to keep two of the three towers in service at all times, ensuring uninterrupted service.

Variable speed drives were installed on each of the nine cooling tower fans and the two main 1,200-ton chillers. The chillers were rebuilt and converted to chlorine-free HFC-134a refrigerant, and the impellers were upgraded to a larger size to increase the mass flow of refrigerant and restore the original chiller capacity.

A new Carrier Comfort Network (CCN) direct digital control automation system monitors and controls the new chillers, cooling towers, and tower fan drives. A CCN WebII Web browser provides Intranet and Internet access.

According to the company, primary operating cost savings have come from the variable speed drives on the two main chillers and the cooling tower fans, condenser water temperature relief, reduced horsepower on the cooling tower fans, and the chiller plant optimization through the CCN controls system.

“Carrier has a longstanding tradition of providing high-quality engineering and installation services that help reduce operating costs and increase the efficiency of our customers’ facilities,” said Dan Smytka, president of Carrier North America BSS. “We are pleased to partner with the Marriott to achieve remarkable energy-saving results.”

For more information, visit www.carrier.com or www.marriottworldcenter.com.

Publication date: 09/08/2008