Page 250 - Alternative Energy Systems in Building Design

226 PASSIVE SOLAR HEATING TECHNOLOGIES

also durable and can be mounted on racks. The panels are available in a glazed version
to accommodate windy areas and colder climates. The disadvantage of this technology
is its numerous system surface attachments, which can limit mounting locations.

Rubber mats Rubber-mat systems are made up of parallel pipes, called headers, that
are manufactured from extruded lengths of tubing that have stretching mats between the
tubes. The length and width of the mat are adjustable and typically are custom-fit for
each application.
The advantage of this technology is the great flexibility of the product, which allows
it to be installed around roof obstructions such as vent pipes. Installations require few,
if any, roof penetrations and are considered highly efficient. Because of the expand-
ability of the product, the headers are less subject to freeze-expansion damage. The
main disadvantage of the system is that the mats are glued to the roof and can be
difficult to remove without damaging either the roof or the solar panels. The installa-
tion also cannot be applied in rack-type installations. Figure 6.5 shows a residential
roof-mounted rubber-mat solar pool heater.

Metal panels Metal panels are constructed from copper waterways that are attached
to either copper or aluminium fins. The fins collect the solar radiation and conduct

Figure 6.5 Rubber-mat roof-mounted solar pool heater. Courtesy of UMA/Helicol.