30 May 2005


Desiccant air conditioning systems as one of heat activated heat pumps are commercially in
operation. The desiccant systems are valuable tools for waste heat utilization. This paper deals with
operating experiences of the desiccant systems combined with waste heat recovery in the field of
supermarket. In comfortable air conditioning and energy saving points of view, humidity is important
factor. In the supermarket, low temperature zone, so called “cold aisle” remains in front of
refrigerated display cases. The desiccant systems eliminate the cold aisle by controlling humidity
independently. Also, frost forming on frozen products and refrigerated display cases are improved.
Influences of the humidity level for energy savings are discussed. Working fluids of the desiccant
systems is air, which relates to indoor air quality (IAQ). Increasing ventilation air increase the level of
humidity, therefore, by using sequencer, it offers ventilation air volume control effectively.
Improvement of the air quality is also examined as sanitizing effects. Since Japanese climate
condition in summer is relatively higher temperature and higher humidity, the desiccant technology
should be the key for optimum air conditioning.