HVAC
stands for heating, ventilation, and air conditioning. In computing and especially in enterprise data centers, HVAC systems control the ambient environment (temperature, humidity, air flow, and air filtering) and must be planned for and operated along with other data center components such as computing hardware, cabling, data storage, fire protection, physical security systems and power. The selection of an HVAC contractor is an important step in planning a data center.
Principles of Refrigeration
•The refrigerant comes into the compressor as a low-pressure gas, it is compressed and then moves out of the compressor as a high-pressure gas.
• The gas then flows to the condenser. Here the gas condenses to a liquid, and gives off its heat to the outside air.
•The liquid then moves to the expansion valve under high pressure. This valve restricts the flow of the fluid, and lowers its pressure as it leaves the expansion valve.
•The low-pressure liquid then moves to the evaporator, where heat from the inside air is absorbed and changes it from a liquid to a gas.
•As a hot low-pressure gas, the refrigerant moves to the compressor where the entire cycle is repeated