An ice storage system can supply chilled water at approximately 0degC (32degF) to 4degC (39.2degF) to air-handling units. A cold-air distribution system supplies air between 8degC (46.4degF) and 10degC (50degF), which is cooled with the chilled water from an ice storage tank, directly into an air-conditioned space. The system allows large temperature differentials, enabling a considerable reduction in initial and running costs for distribution equipment such as fans and air-handling units. However, there are some concerns about the direct supply of cold air to occupied zones. Draught is one of the major concerns with direct cold air diffusion. Conducted draught evaluation experiments with a thermal manikin and experiments with subjects to prove the manikin results, especially under the best and worst diffusion conditions, based on the manikin experiments. The results showed that air cooled to 7degC (44.6degF) and 8degC (46.4degF) caused no draught that annoyed occupants when used with conventional circular ceiling diffusers.

KEYWORDS: year 1995, thermal comfort, air distribution, air handling units, fans, cold, air diffusion, draughts, manikins, occupiers, comparing, experiment, diffusers, measuring, ceilings, air flow, air conditioning