Sailors read instructions while conducting routine maintenance aboard USS Chung-Hoon (DDG 93). (U.S. Navy/MC2 Marcus L. Stanley)

SOUTH CHINA SEA - – The guided-missile destroyer USS Chung-Hoon (DDG 93) is implementing a temperature control initiative with the goal of conserving energy, strengthening operational reach, making programmatic recommendations throughout the fleet and providing support at the depot level.

Chung-Hoon’s temperature control plan is part of the Navy’s yearlong initiative called the Great Green Fleet, highlighting efforts to transform energy use in order to increase operational capability.

“We are aggressively seeking ways to make changes that will improve the ship’s ability to conserve energy,” said Ensign Kyle K. Kaiahua, the electrical officer. “By properly maintaining the ventilation and air conditioning systems, we feel we can gain two to five percent in overall energy efficiency.”

Arleigh Burke class destroyers like Chung-Hoon have five, 200-ton air conditioning (A/C) plants that consume approximately 15 to 20 percent of the ship’s total energy. Normal ship operations require using at least two of the A/C plants to maintain a 44- degree chill water requirement. Warmer climates such as the South China Sea and their homeport waters near Hawaii require operating at least three A/C plants.

The 44-degree chill water is used to cool combat and weapons systems equipment and provide proper ventilation, with a tertiary effect of cooling spaces for the crew.

“It is routine culture on ships to set the thermostat as low as possible for combat systems spaces that house equipment racks with higher heat sources,” said Kaiahua. “This results in significant inefficiency as the A/C systems continue to cool the spaces to unnecessary temperatures, resulting in more energy use.”

Aboard Chung-Hoon, there are 186 thermostats that control the Heating, Ventilation and A/C systems with a manual analog dial. The thermostat dial setting allows the chill water based ventilation to be properly distributed to associated ship spaces.

With a complicated set of systems and the number of thermostats aboard the ship, there are opportunities for significant temperature variance.

In the temperature control initiative, the first step is to locate and verify divisional ownership of every thermostat.

“Once every thermostat has been located and verified, each one must be tested and adjusted to proper working parameters and settings,” said Damage Controlman 2nd Class Keith R. Burke. “One of our goals is to institute a manual process to change the settings of thermostats based on the temperature outside.”

Chill water valves are often more susceptible to corrosion due to the amount of condensation that is generated in their vicinity.

“Another one of our goals is to inspect and replace faulty chill water isolation valves in order to better regulate the chill water system,” said Burke. “This may include a return to solenoid valves.”

“Chung-Hoon’s temperature control initiative is comprised of many small goals, and when they’re met, we’re hoping to reach our ultimate goal of being a more energy efficient warship,” said Cmdr. Vic Sheldon, executive officer of Chung-Hoon. “At this moment, we’re in the early phase of answering questions like: ‘Does setting the thermostat dial to 75 degrees Fahrenheit result in spaces being cooled or heated?’”

Sheldon added that Chung-Hoon’s initiative mirrors the Deputy Assistant Secretary of the Navy for Energy's Maritime Pre-screening Assessment of Conservation Technologies (MPACT) program and has helped influence the decision to work on developing a control centered program for the next M-PACT initiative.

Providing a ready force supporting security and stability in the Indo-Asia-Pacific, Chung-Hoon is operating as part of the John C. Stennis Strike Group and Great Green Fleet on a regularly scheduled 7th Fleet deployment