Environmental Engineering Reference
low-temperature source must be available. The higher the temperature level of the
heat source, the more effi ciently the heat pump can work.
The following heat sources are available to houses (Figure 11.2):
■ Groundwater (water/water)
■ Ground, ground heat exchanger/collector (brine/water)
■ Ground, earth probing device (brine/water)
■ Ambient air (air/water).
The waste heat from industrial plants can also be used.
Figure 11.2 Heat
sources for heat
Depending on the heat source, heat pumps fall into the categories of air/air, air/
water, brine/water or water/water systems. The heat medium supplied is indicated
in front of the oblique. In the case of ambient air, it is air. In the case of constantly
frost-free groundwater, it is water. Because of the risk of frost, a mixture of water
and antifreeze, called brine, fl ows through the pipes in the ground.
The transmitted heat medium is given after the oblique. In most cases, heat pumps
heat up water for heating and domestic use. They are seldom used to heat the air
for hot-air heating systems.
The higher the temperature of the heat source and the lower the temperature
needed for heating, the less electric energy is required to drive the heat pump. Due
to the low heating temperatures, underfl oor heating is preferable to conventional