A DESS is based on a low temperature un-insulated, directly buried two-pipe distribution system that draws energy from various sources. All buildings within the development or municipality can use the DESS for building heating, cooling, domestic hot water as well as a source of non-potable water for toilets, laundry and irrigation.
The DESS is a two-pipe distribution system in which a warm pipe carries warm water for heating and the cool pipe carries cool water for cooling. Buildings connected to the system use heat pumps to draw heat out of the DESS and produce usable heat for the building, domestic water heating or process heating. The same heat pumps can be used to cool the buildings and put heat back into the DESS.
A heat exchanger should be installed between the DESS and building heat pump system to isolate the two loops. There are the two different piping arrangements for the building heating and cooling system. One is for a heating only system, and another is for a heating and cooling system.
It is anticipated that all buildings will derive the majority of their heating and cooling energy from the DESS while using electricity and/or natural gas for peak loads. Preliminary calculations indicated that a heat pump system sized for about 60% of the peak heating load provides over 85% of the annual heating energy for this site, therefore the use of electricity for supplementing the heat pumps is easily justified from a total owning and operating cost basis.