Comfort Control Techniques for the Users of a Room - Comfort Control in Buildings - page 173

Fig. 5.13 Disturbances using strategy (C)
relationship between indoor air temperature and fancoil power has been modelled
with a linear model shown in Eq. 5.16 and the other fancoil variables have not been
taken into account. As has been pointed out in Chap. 2 , the fancoil can be considered
a heat exchanger between the hot and cold water from the absorption machine and
the air which flows through the fancoil. Thus, although the fancoil power is constant
if the water flow or water temperature is not, the energy exchanged between the
water and the air will fluctuate. In Fig. 5.18 the water flow and its temperature are
shown and it is possible to see that neither the water flow nor the water temperature
are constant throughout the test. The reason for these fluctuations is changes in the
energy demand of the rest of the building this day. In fact, the water flow has several
step changes whereas the water temperature fluctuates. Thus, the controller changes
the control signal abruptly, the fancoil power, since the linear model which is used