2[degrees]C) or lower, the IASE cycle can reject 100% of data center heat (assumes 1.
Table 1 shows how the counterflow plate-type HX IASE system performs at various ambient conditions.
Note that the IASE cycle rejects 100% of data center heat for almost 80% of annual hours in Atlanta.
Another type of IASE uses a horizontal polymer-tube heat exchanger (5) (Figure 3).
To better quantify this statement, consider an IASE system operating in Chicago, with a hot-aisle condition (after supply fan heat) of 101.
To facilitate IASE system design, and to predict annual cost of operation, including water consumption, a detailed mathematical model is required.
Figure 5 shows how the scavenger fan flow for an IASE system using a wetted polymer-tube HX is predicted to vary with the ambient wet-bulb temperature for a 1,500 kW data center operating in Chicago.
This figure shows the power consumption as a function of ambient WB for each component in the horizontal polymer-tube IASE system.
At this point, the IASE system is rejecting 1,500 kW of ICT load using only 109.
Clearly, the best way to improve the efficiency of an IASE system, or any data center cooling system, is to design the heat exchanger and duct system for low pressure drop.
The total annual energy used by the IASE system as described in Figure 6, rejecting the 1,500 kW ICT load operating 24/7, is predicted to be 996,900 kWh.
Figure 7 shows the design performance of the polymer-tube IASE system operating to reject an ICT load of 1,500 kW in Chicago.
Note that in the event of a complete failure of the refrigeration system, the polymer-tube IASE HX is still capable of rejecting the full ICT load.
By configuring IASE units with blow-through, direct drive supply fans, the 100% recirculation air flowing within the air handlers is predominantly under positive pressure, and there is no belt dust generated.