The performance of a solar water heating system is influenced
by the product configuration and the local meteorological
conditions. Solar water heaters can operate as a
solar pre-heater in series with a boost tank or instantaneous
gas heater or as a single-tank system with a boost element
incorporated in the solar tank. The collector is usually
mounted at a standard roof inclination, but can also be
adjusted to optimise the performance during winter months
when the hot water demand is the highest. The use of experimentation
to study the effects of these parameters on the
long-term performance of the system is expensive and time
consuming. An alternative way to predict the long-term performance
of a solar water heater is by transient system modelling.
TRNSYS is a transient system simulation program
that can be used to evaluate the performance of a solar water
heater by simulating the performance of inter-connected
solar water heater components i.e. collector, storage tank,
heat exchanger, auxiliary heating and controller. A processor
to compute the radiation on a given collector plane from
a supplied weather data can also be incorporated