Cooling and/or heating of an equipment room without using any freon, no maintenance and almost no consumption of energy

For a long time the praxis has been, that tele-equipment should have a very narrow temperature range when being installed into an equipment room, maybe only a few degrees between the highest and lowest temperature. However, by the new technology that has come out in this field, it has been proved that the temperature can easily vary from in some cases 5/spl deg/C to 35/spl deg/C. This means, that in many telecommunication rooms today, the overheating coming from the equipment is taken away daytime and in many cases the room has to be heated at nighttime. This is waste of energy and it also makes the installation very complicated and expensive. To find a system, which can for example store the cold of the night and use that as a cooling media at daytime and vice versa, would be favourable. The authors describe the development and testing of the Heat Pac concept, which is based on phase change material heat storage, to meet these conditions.<>