Industrialised, Integrated, Intelligent sustainable Construction - I3con

SUSTAINABLE CONSTRUCTION HANDBOOK 2
In winter, the indoor temperatures are uncomfortably low in the simulations. This can clearly be seen
in Figure 3 where the lower comfort limit is exceeded for a significant part of the year. This originated
from the fact that no proper heating is yet implemented in the simulation model. The heating present
in the model consumes a total of 4.6 kWh per m 2 floor area per year, which is roughly equivalent to a
constant heat source of 0.5 W. Better insulation will decrease the heating demand, but further research
is necessary to address this problem.
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Test results
To assess the validity of the simulation model, two ventilation units have been tested in a climate
chamber (Figure 5). The ventilation units contain PCM plates, a heat exchanger and two fans (one for
fresh air, one for stale air) that provide the ventilation in the CAS concept.
Figure 5. Test ventilation units in the climate chamber
Figure 6 represents a 3.5 day test, during which the daytime temperatures climbed to approximately
30°C, while at night the temperatures dropped to about 15°C, with a constant ventilation rate of 28.8
m 3 /h, equivalent to a ventilation rate of 3, or complete refresh of the indoor air of 3 times per hour in
the simulation model. The phase change in the PCM plates can be seen in a plateau in the exit
temperature (the dotted line in Figure 6) after the quick drop in outdoor temperature.
Figure 6. Measured incoming and exiting air temperatures in ventilation unit in 3.5 day cycle