Dehumidification by Condensation

Dehumidification by cooling below the dew point is economical

thanks to energy recovery systems with intelligent controllers.

This process is based on the principle that humid air is dried when it is cooled below the dew point and condensation occurs.

The cooling and dehumidification of OA can be achieved with either a traditional cooling coil (see Video 1) or with an integral plate and frame heat exchanger. (See also Multi-funtional energy recovery system).

Subsequently, the cool air is reheated by heat recovered from the exhaust air.

Video 1

Optimal design

Cold compared to outside air (OA), the exhaust air (EXH) is used to pre-cool the water/glycol circuit, to achieve the highest possible efficiency at high outside air temperatures.

Then the cool dehumidified OA is reheated which in turn cools the water/glycol mixture.

This two-fold pre-cooled water/glycol mixture is then used to pre-cool the OA for example, 89.6°F/32°C to 73.2°F/22.9°C.

Thus, only the remaining cooling needs to be applied to bring the OA to the dew point temperature. The residual heat from the EXH is sufficient in most cases to reheat the supply air (Video 2).

Video 2

As a result, capital cost for the plate and frame heat exchanger and the chiller are lower and so are the operating costs.

If the condenser heat from the chiller is cooled through a heat exchanger in the exhaust air, more capital cost savings for the cooling tower and associated piping are obtainable.

If a chiller is integrated into Konvekta’s energy recovery system and controlled by the system controller, a highly attractive and cost-effective solutions can be realized.