A great part of energy consumption in a ventilation system goes to heating outside air. Great reductions in operational expense can be achieved by transferring the heat from the expelled air to the cold air that is taken in.
Heat rejection is the excess heat from a cooling system which is removed by the condenser/cooling tower. Heat rejection is the total amount of heat energy which is transferred from the cool side to the warm side, plus the work carried out by the compressor.
The heating surface can be an integrated part of the AHU, or be placed directly in the air intake duct. The heating surface is used to warm up outside air before being injected into the building.
HFC as a refrigerant does not contribute to the breakdown of the ozone layer, but contributes to the greenhouse effect. HFC is an abbreviation of hydrofluorocarbon, and describe the molecules’ atom content.
Domestic hot water denotes the hot water that is used in a home for showering, washing, etc. It is produced by heating domestic cold water in either a domestic hot water heat exchanger or in a hot water vessel.
Hot water circulation
Domestic hot water in pipes will cool due to heat loss when there has not been a withdrawal for quite some time. Circulation of domestic hot water ensures a flow inside the pipes, even though hot water is not withdrawn.
Hot water vessel
A hot water vessel is used in production of domestic hot water. The hot water vessel (tank) can be connected to the heating system through district or central heating, or it can contain its own heat source.