Session 18 Paper 4, Heriot-Watt University Edinburgh, 14-15 April 2016
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Comfort cooling applications in the UK are traditionally associated with the maintenance of comfortable space temperature; the control of humidity levels being either consequential or, at best, extremely coarse. The prevailing climate is such that high humidity concerns most occupants on only a handful of days per year and traditional systems are considered satisfactory from a point of view of humidity control.
The drive towards increased energy efficiency has seen an increase in the number of air conditioning systems abandoning traditional methods of providing space cooling in favour of systems which rely on the control of space humidity for their operation.
Chilled beam air conditioning and radiant cooling systems rely on the close control of humidity for proper operation. These are sensible cooling terminal systems which cannot be allowed to condense moisture as the cooling surface is exposed, vertically above the occupied space. Reduced air movement and increased chilled water temperatures associated with these systems allow significant energy benefits to be realised but only if the outside air is efficiently conditioned so as to allow them to function.
In common with more challenging climates it is vital that the sensible and latent cooling be decoupled in order to optimise the benefits of these systems. The case study highlights an example of where heat pipes have been used in the UK to treat outside air in an energy efficient manner. In turn this generates supply air at a sufficiently low dewpoint to allow the incorporation of chilled beams into the design of critical areas.