Environmental Engineering Reference
In-Depth Information
Figure 4.17.
A glazed solar collector.
The storage tank may either be attached to the collector (this is common in warm
climates where heat loss from the tank is minimal) or located separately in a more insulated
place (usually inside the building). In the case of integrated units, the storage tank is
located directly above the panel, where warmer water accumulates. In separated systems
the storage tank is usually located below the collector (since the collector is already located
at the highest point of the building), and so it is not possible to move the warm water by
natural convection. Instead, circulation is forced with the help of an electric pump.
Figure 4.18.
A roof-mounted flat-plate glazed collector that is connected to a water tank
inside the house. This is by far the most common technology for solar heating.
Source:
SolarCoordinates at Wikipedia Commons.
The main alternatives to flat-plate collectors are unglazed collectors and vacuum tubes.
Unglazed collectors function in much the same way as flat-plate glazed collectors, the
difference being that they lack the transparent cover. This makes them considerably
cheaper to produce but also less effective as they quickly lose heat once temperatures drop.
They are mostly used to heat swimming pools, where the desired output temperature is
usually just a few degrees higher than the air temperature.
