What is direct expansion equipment?
A. Direct expansion, DX, or primary exchange is a system where there are two heat exchanging devices. The compressor section is the pump which boosts the pressure and drives the heat to the outside or condenser where the temperature difference cools the refrigerant and it condenses back to a high pressure liquid. The refrigerant liquid then passes to the expansion valve or other metering device where it passes through the restriction to the evaporator section where it is vaporized and absorbs heat from the fluid or air which is passing across the evaporator coil. The vapor then returns to the compressor to continue the cycle. Direct expansion as opposed to secondary exchange or chillers is much more simple. The secondary exchange has a double exchange system where the primary exchanger is as described and then the chilled fluid is then pumped to another exchange system which distributes the final desired results. Among the secondary exchange systems is the cascade system which may be t
Related Questions
- When would a system be designed with chilled water as the cooling medium rather than direct expansion equipment?
- In view of this is it not possible to use direct expansion equipment in a low level displacement application?
- Is is possible to vary the off coil temperature during the cooling cycle of direct expansion equipment?
