The Economist is reporting on a trend toward more innovation in the air conditioning business driven by energy costs and the desire to be more environmentally responsible with the energy we do use. Some ideas the article calls out? Blowing air over ice, thermal coolers that use waste hot water to cool spaces, and (in dryer parts of the planet) evaporative coolers.
And then there’s this
However, researchers at the National Renewable Energy Laboratory (NREL) in Colorado have designed an evaporative system that sprays ambient-temperature water into warm air to cool it, but in a way that also lowers the humidity. NREL uses syrupy liquids which contain salty desiccants to soak up the humidity. Hot water is used to heat the syrups and dry them out. NREL’s technology, known as “desiccant-evaporative cooling”, is still being developed, but it requires little power, not least because the hot water can be obtained from solar panels. Ron Judkoff of NREL thinks the process will consume only about a fifth of the energy of conventional air-conditioners, depending how dry the climate is to begin with.