This concern is a serious problem because this collector could be built with better
insulation quality and/or be exposed to hottest climates that were
studied here, reaching easily temperatures above the point of risk
(z75 C) for LDPE. Of course we could build the collector by using
materials of better qualities (as HDPE) that could withstand higher
temperatures. However, despite the fact this choice is more
expensive we want now to show a different solution emerged from
the design. Fig. 8 illustrates a recirculation loop (with a small pump)
added between the tank and the hose collector, connected with two
on/off valves. This auxiliary circuit can be used during holidays in
order to interchange the water of hose and tank, every time the
hose is extremely hot. Although in this way the temperature of tank
would increase day by day, this trend could be counterbalanced by
using also nocturnal recirculation and so, using the collector as a
cooling device.