What is it?
Membrane air conditioning is a category of cooling technologies that utilizes hydrophilic (attracted to water) membranes to dehumidify air efficiently as part of a cooling system.
How does it work?
Warm, moist air enters the system and the water (in vapor form) in the air is pulled out in the membrane. A vacuum pump then pulls the water vapor out of the membrane to a condenser, where it is turned back into liquid water for evaporative cooling or use in a heat exchanger. No heat is added or removed during this process. Because the water is removed with the membrane, the cooling coil downstream does not have to reduce the air temperature to 55°F to make the air comfortable, reducing overall cooling energy, even once the vacuum pump and condenser energy are accounted for.
What are the most appropriate applications?
Any building where tight control of space humidity is not crucial can be a good fit. This technology is most effective when paired with evaporative cooling, so humidity levels may increase slightly compared to conventional systems.
What are the savings?
In a Midwestern climate, membrane-based systems combined with desiccants and/or condensers can improve cooling efficiencies by 20% (condenser) to 60% (desiccants) over typical vapor-compression systems.
What are the non-energy benefits?
Membrane systems can recover water from the air and use that water to supply evaporative cooling systems, so they can produce significant water use savings in some cases.
What is the cost?
Costs are not available at this time, due to the small number of commercially-available products.
What is the status/availability of the technology?
This technology is still in the research phase, but a few commercial products are available, especially for use in data centers.
What kinds of incentives/programs are available?
Right now, this technology would be evaluated under Custom Rebate programs. Incentives will vary depending on customer specifics.