Environmental Engineering Reference
In-Depth Information
2250
kWh
therm al heat boiler
drinking water boiler
thermal heat solar
drinking water solar
2000
1750
1500
1250
1000
750
500
250
0
Jan.
Feb.
March
April
May
June
July
Aug.
Sept.
Oct.
Nov.
Dec.
Figure 6.20
Typical progression of thermal heat and hot water requirements in Germany
and proportion of solar system versus conventional heating based on the requirements
of an old building with a total solar coverage of 20%.
■
Collector surface with vacuum - tube collectors: 0.6 m
2
per 10 m
2
living area
■
Storage size: at least 50 litres per m
2
of collector surface
Variant 2: Medium-sized system for higher share of solar coverage
■
Collector surface with fl at - plate collectors: 1.6 m
2
per 10 m
2
living area
■
Collector surface with vacuum - tube collectors: 1.2 m
2
per 10 m
2
living area
■
Storage size: 100 litres per m
2
of collector surface
An optimal design would of course also take into account the actual heat require-
ments. The difference in requirements between an old building and an energy-saving
three-litre house is considerable. Table 6.1 shows simulation results for optimal
systems that were dimensioned according to the outline design described.
Table 6.1
Solar coverage.
Old
building
Standard
new-build
Three-litre
house
Passive
house
Heat requirement for hot water in kWh
2700
2700
2700
2700
Heating requirement in kWh
25 000
11 500
3900
1950
Solar coverage Variant 1 (small system)
13%
22%
40%
51%
Solar coverage Variant 2
(medium-sized system)
22%
36%
57%
68%
Assumes following: Berlin location, orientation 30 ° south without shade, 130 m
2
living area, optimal fl at-plate collector with combination storage.
Although the collector with the medium-sized system is double the size of the small
system and the storage is four times larger, this does not mean that the solar cover-
