In order to achieve the most economical operation, building services must be designed to provide sufficient flexibility for load transfer and energy use control.A heat energy storage technology, through which "storing high or low temperature energy for later use, to bridge the time gap between energy availability and energy use "can be considered a useful way to achieve this goal.Thermal energy storage (TES) can be considered as a useful tool to effectively reduce the number of machines operating at constant loads throughout the day by dispersing the total load within 24 hours.Therefore, any type of TES system can be considered as a useful tool that can not only reduce the overall environmental impact, but also provide considerable cost of economic operation and pre-investment capital for cooperation.Generate the application.Thermal energy storage in the form of water tanks has the advantages of universal availability, low cost and transmission through other system components.However, compared with the potential thermal energy storage commonly known as phase change materials (PCM) co-crystals, the traditional water-based TES system based only on thermal storage requires a large volume.Positive temperature co-crystal solution is a mixture of two or more chemicals, at 0 °c (32 °c) when mixed in a specific ratio) the water freezing temperature above has freezing point they provide thermal energy storage facilities between 4 °c (39 °f) and 117 °c (242 °f.While the term "co-crystal" is widely used to describe materials of interest to us, a better description will be "phase change material" ("PCMs ").PCMs can be roughly divided into two categories;"Organic Compounds" such as ethylene glycol and "salt-Based on the product "(such as salt of mirabilite ).A series of new solids recentlySolid PCM solutions have been developed to meet high temperature applications such as steam and high temperature petroleum thermal storage applications.The most common products for mass installation are brine-based PCM solutions because they are low cost and have a wide range of material sources, but because they are water-based, they must be packaged in air-tight containers.These containers can be placed in the air or water circuit as a buffer between the system and the heat source.In addition, free cooling cycle, absorption chiller, Co-The combination of power generation, solar, hot water and heat recovery TES systems provides designers with a new vision to control the energy balance to match the load and power demand/consumption of the entire system.In particular, PCM energy storage on the hot and cold side of the ground source heat pump provides a technically attractive and economical choice, when the system needs heat, the other side of the heat pump circuit, that is, the cooling output is stored in a colder PCM energy storage tank instead of being damping to the ground.When cooling alone or at the same time is required, this usually stores the wasted energy on the ground and can be used to cool the system.The storage of normally wasted energy effectively reduces the number of hours the heat pump and the entire system operate.The above operation can also be repeated in the same way for the heating side of the circuit, and will not waste any energy on the ground, nor will it reverse the major energy loss that causes the thermal inertia of the processing system, the operating cost of the soil source heat pump can be reduced by 50%.The designer's task is to explore all the technologies available to improve efficiency and apply diverse technologies where possible to minimize CO2 emissions associated with energy use.For cooling applications with some environmental and economic alternatives, this may be the answer.\rZafer Ure, M.Sc., C.Eng., MCIBSE., MASHRAE., MInstR., Is the managing director of environmental process Systems Co., Ltd.Having 25 years of experience in the HVAC industry and writing many papers for industry conferences and magazines.www.pcmproducts.Can contact and Zafer at 44 1733 243400 or z.ure@epsltd.co