According to NREL’s senior mechanical engineer and co-inventor of the technology Eric Kozubal, the present idea uses less than 50% of energy compared to the conventional air conditioners. The system not only cools and dehumidifies the air but also cleans the carbon content normally present in the atmosphere, helping the environment to become healthier and pollution free.
DEVap involves dividing (through polymer membranes) and forcing air through two discrete streams. Water is allowed to pass through one air stream, making it wetter and cooler through evaporation. This cool air decreases the temperature of a membrane, which in turn cools the air on the other side of it. The second stream of air is first dried up by passing it through desiccants and then is blown across the above cooler side of the membrane. This results in a perfectly cool and dry air output.
The desiccant used here is a liquid solution of calcium chloride, which is about 44 percent salt by volume. It is enclosed in special membranes which contains micrometer sized holes suitable enough to allow the water molecule to pass through but obstruct the desiccant fluid from seeping out.
So far everything seems pretty easy, but a logical and an obvious question would be what happens when the desiccants reach their saturation point. Things may go horribly wrong as then instead of dehumidifying, the system would start increasing the relative humidity of the room by adding up the water content of the desiccant,s and the cooling process would also stop.
The problem is simply solved by introducing a small heater and a blower into the system. Before the desiccants can reach their saturation point, the electric heater and the blower is automatically switched ON. Air heated by the heater is blown through the desiccants, which lose their moisture content into the hot air. This moisture absorbed hot air is then forced through an outlet vent back into the atmosphere. The desiccants again become fresh and reusable. The process is called recativation.
Although extra and a substantial amount of electricity may be consumed in the process, it cannot be considered a negative aspect of the system, as the overall power consumption of it still remains well below 50% than that of conventional air conditioners.