IEA Solar Heating & Cooling Programme Task 31: Daylighting ...
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evaluation of the inside conditions (visual, thermal, air quality, room occupancy, energy
consumption, etc).
Some of the sensors may provide a certain redundancy. If the investment cost issue has
the absolute priority over any other considerations, a minimum set of sensors may be
used (for instance, outside temperature and solar radiation are correlated, and only one
sensor could possibly be used), but in general redundancy is desirable since it allows the
operation of the control system even with some broken sensors, although with a light
degradation of the control quality.
2.6 Control system reliability
In a close relationship with the sensor redundancy, the requirement of control system
reliability is of prime importance.
2.7 Providing the optimal comfort and understanding the physiological discomfort
mechanisms
The primary aim of the building services and their control systems is to provide an
optimal comfort to the building users. In general, the comfort of the users (typically,
visual, thermal and air quality) is more important than any other consideration.
In order to elaborate adequate control algorithms for building services, the physiological
discomfort mechanisms have to be correctly understood. For thermal comfort, a rather
well-accepted and well-proofed formalism, basically developed by P.O. Fanger and based
on the observation of a large sample of persons, is available. For visual comfort, the
situation is more difficult and several comfort indexes are used through the world, none
of them being widely adopted by the scientific community.
A pre-requisite for the improvement of control algorithms would be a better
understanding of the factors having an influence on the comfort level. Currently, already
rather sophisticated comfort models do exist, and they should be used whenever possible
when designing control algorithms.
2.8 Energy considerations
Normally, energy considerations are secondary when compared with inside comfort,
because even a small increase of comfort can pay for a large quantity of energy
consumption. Nevertheless, if the same comfort can be reached by different algorithms
corresponding to rather different energy consumption, the best one should of course be
chosen.
When tariffs are modulated in function of the current hour in the day (typically for
Summary :
2.7 Providing the optimal comfort and understanding the physiological discomfort mechanisms The primary aim of the building services and their control systems is to provide an optimal comfort to the building users. 2.8 Energy considerations Normally, energy considerations are secondary when compared with inside comfort, because even a small increase of comfort can pay for a large quantity of energy consumption.
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control,energy,used,algorithms,sensors,isual,rather,system,considerations,building,redundancy,quality,thermal
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