Emerald Shapery Center Thermal Storage
Energy control systems received high priority in the Emerald Shapery Center project design. Included in this category are the H.V.A.C. (heating, ventilating, and air-conditioning) equipment, lighting systems, telecommunications, and electronic monitoring devices. Each floor of the office tower contains its own air handling unit to increase efficiency. A chilled water system is also an integral part of the energy saving mechanical systems at the Center. These mechanical systems utilize innovative design to provide efficient, cost effective energy management.
They range from the simplest to the latest state-of-the-art energy conversion equipment. Each room in the hotel utilizes an individual fan coil air conditioning unit. The cooling to each unit comes from chilled water pumped through the system from the ice storage system located in and below the basement. In addition to the efficiency of operation, the system used in the hotel portion of the project is also the least expensive because as all units are stacked on each floor, the installation cost is low. Plumbing is minimized. Each floor of the office tower contains its own air handling unit.
This ice storage system is used in conjunction with and is an integral part of the energy savings systems at the Emerald Shapery Center and has been created through the joint efforts of the Developer and San Diego Gas and Electric Company. Emerald Shapery Center working in conjunction with San Diego Gas and Electric has found a way to utilize and store excess electrical energy generated by the utility company during off hours. The electricity used during the late night and early morning hours is converted to thermal energy and stored to be used at a different time of day. Air conditioning for a hotel or office building during a hot summer day can be one of the most costly consumers of expensive peak load electric power. Through the use of ice manufactured in 13 8' x 52' water storage tanks, the above described otherwise wasted lower cost electricity is stored and consumed later. As the water freezes it has the capacity to release large amounts of heat energy. Large water storage tanks located below the parking garage store the ice. During late night and early morning the electricity is used to run the air conditioning chillers and compressors. The cold water freezes and stores the energy until it is needed the next day.
During the day the chiller and compressors are turned off and only the blower fans are needed to cool the building, resulting in a substantially lower electric load requirement during the day. A smaller chiller will also result since it will not be required during peak load periods. The energy required to cool air at night with a smaller temperature differential is much lower which adds to the capital savings and improves efficiency by allowing the chilling system to be downsized. Additional savings are generated because of the use of colder air in the air handling system. Colder air requires less volume and, therefor, the ducts can be substantially downsized. With the smaller ducts further savings result in the ability to reduce the floor to floor height.
Each floor also has its own outside air intake. To improve the system's efficiency the air intake for each floor enters the building on the north side in the exact location which is the furthest point from the sunlight during the day. The minimization of the temperature differential between outside and inside cooled air will result in energy efficiency and savings. Because the building core is located closer to the north wall, there is a capital savings resulting from the air intake ducting being shorter.
Both scientists and doctors have proven that air which is positively charged with ions is unhealthy to humans, animals and plants, and conversely negatively charged air is healthful. ( see The Ion Effect by Fred Soyka, Bantam Books 1981) It has been determined that the air normally in high rise buildings is unhealthy because it is positively charged. This results from air moving long distances through twisting and turning air ducts. The surface of the ducts strips the air of electrons resulting in positvely charged unhealthly air. By minimizing the ducting, and by bringing in fresh air from the outside of every floor, this condition is minimized.
There is also a substantial operating savings using this type of system. Unlike in many high rise buildings, the entire air conditioning system will not need to be running to cool one floor. During weekends and nights only that portion of the system called for need be operated. This affords the tenant the ability to work on weekends in pleasant conditions without the need for paying to turn on and operate the entire building system.