analysis of the influences of solar radiation and façade glazing ...

3.5 Optimization of a solar domestic hot water system 90
It was decided to check the correlation between the solar passive gain and the relative
height of the glazing system as was done earlier for the heating period.
(Window Heat Gain Energy -
Window Heat Loss Energy)
per 1m2 of glazing system
[kWh/m2 ]
120
115
110
105
100
95
90
85
80
75
70
0 2 4 6 8 10 12 14
Middle of the storey’s height [m]
Fig. 3.43: Dependence of the solar gain and heat loss difference on the middle of the storey’s height during
the warm period.
The windows’ energy balance (Fig. 3.43) shows that the difference between the first and
the last floor is small in comparison to the results which were obtained for the heating
season. This effect comes from the sun's higher elevation above the horizon.
3.5 Optimization of a solar domestic hot water system
A developed DHW system is composed of the tube solar collectors, storage tanks and an
auxiliary water heater. As commonly known, the storage tank accumulates heat from the
solar collectors. The auxiliary water heater provides additional heat if the storage tank
water temperature is too low. A connection diagram, which was assumed in the
computational model of a DHW system, is shown in chapter 3.1.1.
3.5.1 Description of the solar collectors
The solar domestic hot water system is designed using 14 vacuum tube collectors (heat
pipe principle) VITOSOL 300-T SP3, which are described by the following specifications:
� gross area – 2.88 m 2 ,
� absorber area – 2.05 m 2 ,
� aperture area – 2.11 m 2
South‐Balcony window
South‐Window
Approximation