Light Cooling (passive) is mainly used to cool down the room. This is an energy efficient, non-condensing cooling that is used in combination with heat pump systems. In winter, the building is heated by means of soil heat. In summer, this system returns the heat to the soil, which will cause the inside temperature to decrease. The circulation pump is the only part that will consume energy, and this in order to pump the water through the pipes and to deliver it to the radiators. These environmentally friendly cooling systems can drop the temperature by 3 to 5 degrees. They ensure that the room is cooled down slightly without having to use a lot of energy.