Phase change material pack

A phase change material pack comprises a laminate of a first conducting panel 64 and a second conducting panel 65 enclosing a portion of phase change material (PCM), and the PCM incorporates thermal conductors 63. The thermal conductors may extend in a transverse direction from one or both the conducting panels, may form hexagonal cells, may be carbon black conductive compound mixed into the PCM. The panels may be corrugated (fig 13), may comprise a plurality of projections 81, may be made from aluminium, steel or plastics. The PCM may be salt, salt based hydrate or organic material (paraffin). If salt based hydrate a thickening agent such as Xanthan or Laponite may be used. The packs may be housed side by side with spaces separating the packs forming channels for the flow of a fluid (air) therethrough thereby defining a PCM module (fig 5). One or more thermal conductors 81 extending transversely may form the channels (fig 15). The PCM module may incorporate a Peltier cooler (figs 23 — 26) or evaporative cooler (figs 27 — 29), and may be used in an air conditioning arrangement (fig 35).