posted on 2010-11-16, 10:28authored byA.C. Wheatley
Prompted by the energy crisis in the 1970's, European level fiscal and financial
measures encourage energy efficient building design. "Mixed mode" strategies can
be employed in buildings with moderate thermal loads, this approach can reduce
building energy usage, and by inference, reduce C02 emissions. A mixed mode
approach might employ chilled surfaces with displacement ventilation. This thesis
investigates the performance and integration of one form of chilled surface design,
(a sub-dew point chilled beam), within mixed mode strategies.
Sub-dew point chilled beams have a surface temperature that is at or below the
zone saturation temperature, this increases the cooling capacity of the chilled beam
and consequently produces a latent heat transfer addition due to condensation
mass transfer. This thesis describes the sensible and latent modelling approach
which models the zone, sub-dew point chilled beam and mixed mode strategy
thermal plant response to external disturbances. The thesis describes the use of
an Enclosure Comfort Performance Indicator that acts as the objective function
for the optimization of the mixed mode strategies with and without the integration
of the sub-dew point chilled beam. The implementation of the Complex method
for finding the operational optimums of the mixed mode strategy is described, and
its effectiveness at finding the optimum solution evaluated.
Normalised energy, cost and comfort performance indicators are used to assess the
overall performance and integration of the sub-dew point chilled beam for different
mixed mode strategies, for the ambient test conditions and for different thermal
weights of building construction.