Desiccant Cooling A good deal for everyone Henrik Näsström

In general Creates air cooling from district heating An alternative to traditional methods Can make incoming air colder from 30°C to 15°C. Using district heating instead of electricity No noisy compressor or condenser, no environmentally harmful refrigerants Built using proven standard components Requires large ventilation space

Economy More expensive than conventional units (30-50%) Very good heat recovery Increased basis for environmentally friendly electricity due to CHP Equal investment costs (in this case) Lower operating costs (in this case)

Components

Evaporative air coolerDrying rotor

Evaporative cooler If you add 1 gram of water to 1 kg of air you reduce the air temperature 2,5°C Drying rotor If you take away 1 gram of water from 1 kg of air you increase the air temperature 3,3°C Physics

30 ºC 10 g/kg 40 ºC 7 g/kg 25 ºC 7 g/kg 25 ºC 10 g/kg 20 ºC 12 g/kg 17,5 ºC 10 g/kg 55 ºC 12 g/kg 35ºC 12 g/kg 45ºC 15 g/kg Function

ROOM 45,055,035,020,025,0 15,512,5 10,5 Delta T =7,5 Delta X =0,5 30,040,025,017,5 10,07,0 10,0

Heating demand of 540 MWh in a building 80% efficiency for a conventional ventilation gives a need of 108 MWh 90% efficiency with desiccant cooling system provides a heating requirement of 54 MWh In summer it need about MWh of heat to create desiccant cooling 0,7 – 1,0 kWh of heat to generate 1 kWh of cooling Example

Consumption