Retrofit

Retrofitting Strategy	Installation of cold-aisle enclosure which can totally separate it from hot-aisle
	Hot/cold aisle is a layout design for server racks in a data centre. The goal of it is to increase the effectiveness of cooling system by managing air flow in data centre. This design involves lining up server racks in different rows withdrawing cold air at the same aisle and exhausting hot air to another aisle to minimise cross-over between hot air and cold air. The servers are positioned back-to-back such that hot air is discharged to the same aisle. With cold aisles containment, cold air is directed only to the front of the servers, where it is pulled through the servers into a warm aisle or a space near a warm air return to be re-cooled. Except for the cold aisle, other space in the data centre hall is at higher temperature. With hot aisle containment design, the hot air is efficiently captured and channeled back to the CRAC.
	Consideration
	With cold aisle containment, the cooling effectiveness is higher, but most of the area in the data centre hall may not be suitable for people working. Additional fire detection and firefighting requirement for the contained aisles.
	Estimated Saving
	Waterside: 1/COP_CH_PRE * QBLDG_PRE * OPHR_PRE,yr – 1/COP_CH_POST * QBLDG_POST * OPHR_POST,yr) Where QBLDG_POST = QBLDG_PRE * (LWH)_POST/(LWH)_PRE Airside: kW_AHUNAHULF_AHUOPHR_PRE – kW_CRACNCRACLF_CRACOPHR_POST Where LF_AHU = 1 for CAV or 0.7 for VAV LF_CRAC = 0.4 for VAV Please click HERE to view the list of terminology.