There is a tendency for modern buildings to have a high need for cooling. This is particularly significant for high occupancy buildings with passive heat gains from people, lighting, computers and high solar gains from extensive use of glazing in the facade. Many commercial buildings in South East England have annual cooling loads which are larger than the heating loads, even in the cooler months. Supermarkets have high cooling loads from process cooling of food chiller cabinets.
For these buildings an ICAX asphalt solar collector can be used in reverse as an asphalt heat rejector. The asphalt heat rejector can be used at night to reject heat from the building to the night sky. It can also be used on winter nights for heat rejection from a thermalbank. This allows a large volume of ground to achieve significantly lower temperature which can be maintained over the spring and used in summer for the building to reject heat to – this permits natural cooling of the building at a fraction of the cost of air conditioning.
One advantage of employing a thermal bank is that heat rejection can be scheduled to take place when external temperatures are low - at night or in winter. If an asphalt heat rejector is not suitable for a particular site then there are alternatives that can be used, like dry air coolers.
A Solardec Watertight Solar Collector can also act as an asphalt heat rejector. It is not possible to use standard flat plate solar collectors as heat rejectors in this way – they are specifically designed to retain heat.
See Renewable Cooling.
In the case of aircraft parking stands warmth can be fed through an array of pipes embedded in the surface to ensure that the surface remains free of ice in winter. The principles are the same as for heat rejection, although the detail design parameters need to be optimised for this function.
Although an asphalt heat rejector performs the opposite function to an Asphalt Solar Collector it is, in fact, the same thing: a heat exchanger which absorbs solar heat on summer days and rejects heat when the outside temperature is lower than the building – or Thermalbank – being cooled.See Ground Source Heating See Ground Source Cooling See Ground Source Energy