Solar hybrid air-conditioning design for buildings in hot and humid climates - Solar Energy Sciences and Engineering Applications - page 498

Figure 15.3.3 SHAC using absorption chiller for displacement ventilation.

Table 15.3.4 Summary of cooling and energy performances of SHAC and conventional systems for
DV and MV.

Year-round Year-round

Type of averaged Year-round total E p per Energy saving

ventilation T z ( ◦ C)/ Year-round averaged AC area vs.WCVCC

(kWh/m 2 )

Type of system collectors RH z (%) averaged SF COP ch /COP dc using MV

SHAC-Ab DV 25.1/59.1 0.905 0.809/0.845 192 49.5%

MV 24.9/58.3 0.804 0.779/0.904 246 35.3%

SHAC-Ad DV 25.0/59.3 0.741 0.475/0.880 310 18.3%

MV 24.9/58.4 0.590 0.460/0.919 445 − 17.2%

WCVCC DV 24.4/70.3 NA 3.556/NA 273 NA

WCVCC MV 24.8/58.9 NA 3.195/NA 380 NA

Remarks: NA means not applicable.

and conventional AC systems, as shown by Fong et al. (2011b), are consolidated in
Table 15.3.4.
Table 15.3.4 summarizes the year-round performances of the different systems. All
of them can maintain satisfactory indoor conditions of averaged T z and RH z , except
the WCVCC for DV, which has a RH z of 70.3% due to the relatively high supply
air humidity ratio. When compared to the conventional WCVCC for MV, the SHAC
systems are technically feasible, with a primary energy saving of 49.5% for SHAC-Ab
and 18.3% for SHAC-Ad. In the same ventilation strategy the SHAC-Ab has a primary
energy saving of 29.7% against the conventional AC system for DV, and 35.3% against
that for MV. Even the SHAC-Ab for MV has an energy saving of 9.9% against the
conventional system for DV. This really demonstrates the effectiveness of the hybrid
design of solar air-conditioning systems using absorption chillers.
When compared to MV counterparts, the adoption of DV can reduce total primary
energy consumption from 246 kW/m 2 to 192 kW/m 2 (a 21.9% drop) in SHAC-Ab; and