Active Thermal Cooling Technologies - Low Energy Cooling for Sustainable Buildings - page 121

Double Effect ACMs

Tanaka introduced a combined single/double effect H 2 O/LiBr ACM that works in
double effect mode by using fuel at a higher COP and in SE mode using solar
energy. Two ACMs of 20-30 kW cooling capacity and COPs of 1.1 (DE)/0.6 (SE)
have been installed in the office building of the Energy Engineering Department of
Oita University in Kyushu, Japan, and at the Kabe office building of the Chugoku
Electric Company in Hiroshima, Japan (Kimura, 1992).
The American company Solargenix Energy, LCC (formerly Duke Solar Energy,
LCC) has had a commercial building project in Sacramento, California, since 1997,
where a DE McQuay ACM with a 70 kW cooling capacity and a COP of 1.1 to 1.2
is used, which is driven by 200m 2 of integrated compound parabolic concentrator
(ICPC) VTCs at 165 ◦ C heating temperature. These special VTCs are internal mirror
coated (Duff et al ., 2003). Solargenix Energy also developed a roof integrated system
with a fixed parabolic reflector and tracking evacuated-tube receiver and has been
running a modified hot-water-driven Yazaki 176 kW DE ACM with a 930m 2 Power
Roof combined with a 7.5m 3 storage tank at a large commercial office building in
Raleigh, North Carolina, since July 2002. The chiller has a COP of 1.23 (Gee et al .,
2003; Guiney and Henkel, 2003). Another project of Solargenix Energy (since 2003)
is the municipal utility building at the Sand Hill Power Plant control centre in Austin,
Texas. The solar system consist of 360m 2 of non-evacuated CPC solar thermal col-
lectors and a 9.5m 3 pressurized thermal storage tank which drives a 95 kW Yazaki
hot water SE ACM. Further detailed operating data for the ACM is not available
(Sklar, 2004).
A further solar cooling project of SolitemGmbH is the Hotel Iberotel Sarigermepark
in Dalamen, southern Turkey. A steam-fired, DE Broad ACM with a 140 kW cooling
capacity has been running since April 2004 on superheated steam which is produced
by 180m 2 of newly developed parabolic trough collectors (PTCs). The operating
conditions are a pressure level of 4 10 5 Pa at a temperature T h of 144 ◦ C for the

saturated steam, and a cooling water inlet temperature of 27 ◦ C. A COP of 1.3 has
been reached (Lokurlu et al ., 2002; Kruger et al ., 2002). Further projects are under
construction or planned, for example at the Hotel Grand Kaptan in Alanya, Turkey,
and at the Hotel Iberotel in Ortaca, Turkey.

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Projects with NH 3 /H 2 OSEACMs
An early project was the 12 kW NH 3 /H 2 O SE ACM with FPCs for a laboratory test
stand at theGradevinski Institute of theUniversity of Split, Croatia, whichwas installed
in 1979. The unit was in operation for 200 hours only in 1979. The installed ACM
reached a COP of 0.55 at temperatures T h 80/76 ◦ C, T c 25/33 ◦ C and T o 12/6 ◦ C
(Podesser, 1982).
At the TZ technology centre in Kothen, Germany, a SE NH 3 /H 2 O ACM from ABB
with a 15 kW cooling capacity has been operated since 1998 for air-conditioning a