Solar hybrid air-conditioning design for buildings in hot and humid climates - Solar Energy Sciences and Engineering Applications - page 502

Table 15.4.1 Summary of cooling and energy performances of SHAC and conventional systems in the
cities in Southeast Asia and South China.

Annual global
horizontal
irradiation
(kWh/m 2 )

Year-round
averaged
COP ch /
COP dc

Year-round
total E p per
AC area
(kWh/m 2 )

City
(latitude,
longitude)

Energy
saving vs.
VCC

Type of
system

Year-round
averaged SF

Bangkok 1756.2 WCVCC NA 3.117 548 NA

(13.92 ◦ N, 100.60 ◦ E) SHAC-Ab 0.857 0.773/0.968 273 50.3%

Guangzhou 1073.4 WCVCC NA 3.175 366 NA

(23.17 ◦ N, 113.33 ◦ E) SHAC-Ab 0.714 0.782/0.958 271 25.8%

Hong Kong 1268.8 WCVCC NA 3.195 380 NA

(22.32 ◦ N, 114.17 ◦ E) SHAC-Ab 0.804 0.779/0.904 246 35.3%

Kuala Lumpur 1466.4 WCVCC NA 3.092 536 NA

(3.12 ◦ N, 101.55 ◦ E) SHAC-Ab 0.777 0.777/0.915 313 41.7%

Manila 1537.9 WCVCC NA 3.090 550 NA

(14.52 ◦ N, 121.00 ◦ E) SHAC-Ab 0.753 0.774/0.993 330 39.9%

Singapore 1587.0 WCVCC NA 3.067 555 NA

(1.37 ◦ N, 103.98 ◦ E) SHAC-Ab 0.809 0.772/0.977 302 45.7%

Taipei 1388.1 WCVCC NA 3.171 395 NA

(25.07 ◦ N, 121.55 ◦ E) SHAC-Ab 0.862 0.778/0.859 222 43.9%

Remarks: NA means not applicable.

From the table it is clear that there is substantial primary energy saving of the
SHAC against the conventional system, ranging from 25.8% to 50.3%. Particularly
in tropical cities, like Bangkok, Kuala Lumpur and Singapore, the energy saving is
well above 40%. This indicates the direct contribution that annual global horizon-
tal irradiation to the SHAC can make, leading to relatively high SF in these places.
As the SHAC system has independent temperature and humidity controls, it is suit-
able for those premises even with high space sensible and latent loads. Along with
the various renewable energy incentives and policy implementation advocated in the
related cities, solar air-conditioning systems should become technologically attractive
and economically competitive.

15.5 CONCLUSION AND FUTURE DEVELOPMENT

The cooling and energy performances of solar hybrid air-conditioning systems are
assured in hot-humid climates. With its hybrid design and independent temperature
and humidity controls, the SHAC system can be designed for sharing zone load and
ventilation load; for radiant cooling with passive and active chilled beams; for new
indoor ventilation strategies (both DV and SV); and for premises with high latent
load. In all these SHAC systems, solar-thermal gain can be the primary energy source.
Due to the intermittent nature of solar irradiation, it is inevitable that SHAC will
require auxiliary heating, which may demand fossil fuel consumption. Despite this, the
primary energy saving of the SHAC is still guaranteed compared to the conventional
compression refrigeration system. For buildings with high sensible and latent loads,