Modeling and Design of Net ZEBs as Integrated Energy Systems - Modeling, Design, and Optimization of Net-Zero Energy Buildings - page 63

2.2.2.1 Solar Thermal Collectors
Solar thermal collectors convert absorbed solar radiation to useful thermal
energy for domestic hot water, space heating, or industrial processes. A
collector mainly consists of an absorber that absorbs solar radiation and
transfers it to a working fluid that can be used directly or indirectly in the
thermal process. Different types of solar thermal collectors are available
on the market: unglazed transpired collectors (UTCs), flat plate collectors,
vacuum collectors, and concentrating solar collectors.
Unglazed Transpired Collectors
Unglazed transpired collectors are mainly used for solar air preheating in
ventilation systems, as well as in applications such as drying. The JMSB
BIPV/T system described in the previous section uses an UTC system with
specially designed PV panels and attachment brackets to preheat fresh air
for the building in winter, while generating electricity.
Flat Plate Collectors
These are the most commonly used in building energy applications. For the
same overall configuration, flat plate collectors can have water or air as a
working fluid. Air collectors can be open loop or closed loop.
A flat plate collector ( Figure 2.16 ) consists of a transparent cover system, an
absorber,insulation,andaframe.Almostallsolarradiationpassingthrough
the cover is captured by the absorber plate. A working fluid circulating in
tubes integrated to the absorber collects the heat.