Revenge of the swamp cooler

[freebeard]

www.technologyreview.com/2023/10/04/1080128/2023-climate-tech-companies-blue-frontier-air-conditioning-energy-storage-climate-technology/

Blue Frontier’s approach has two steps: First, a salty mixture known as a desiccant sucks moisture out of the air, reducing its humidity. Then, some of that now-dry air moves past a wet surface. Water evaporates back into the dry air and lowers its temperature (a process known as evaporative cooling). That cooled air then passes by the remaining air in the system and cools it, too.

The company says this process makes its AC units three times more efficient than conventional systems and reduces their overall energy consumption by more than 60%.

The first step is likely some form of enthalpy wheel.

Thermal wheel

A thermal wheel, also known as a rotary heat exchanger, or rotary air-to-air enthalpy wheel, energy recovery wheel, or heat recovery wheel, is a type of energy recovery heat exchanger positioned within the supply and exhaust air streams of air-handling units or rooftop units or in the exhaust gases of an industrial process, in order to recover the heat energy. Wikipedia

[cRiPpLe_rOoStEr]

Had it been possible to recover the water removed by the dessicant, it could eventually make sense. But anyway, I remember seeing some air-conditioning systems which resort to cold water recirculation, as it has a higher thermal conductivity, so lowering the temperature of water through conventional refrigeration (sort of an oversized fridge) and then pump it through pipes inside a building would still be nearly as effective, consume less energy overall, and not take much moisture out of the air.

But anyway, unless it's a full-EV, most likely the moisture extracted from the air by a conventional air-conditioning system could still be used for water injection in the engine.

[freebeard]

Another important feature of the startup’s system is energy storage. The salty brew absorbs moisture from the humid air during the day, but it can be dried out by a heat pump at night when electricity demand is lower. That way the drying process doesn’t place as great a burden on the grid, which effectively is a form of energy storage. Then, when the sun comes up and temperatures start to climb, Blue Frontier’s AC can run for about four hours on the energy stored within that mixture.

When
So far, the company has raised at least $26 million through grants, prizes, seed funding, and a Series A round in July 2022 led by Breakthrough Energy Ventures. Betts says that’s enough to get them through the end of 2024.

Blue Frontier’s first product will be an AC unit with a capacity similar to the air conditioners most commonly used today in commercial buildings. Eventually, the company hopes to make units suitable for homes.

.

[cRiPpLe_rOoStEr]

May be OK for stationary applications, but not for vehicles. Well, maybe for buses/coaches? Or sleeper cabs on trucks?

[Hersbird]

Originally Posted by cRiPpLe_rOoStEr

Had it been possible to recover the water removed by the dessicant, it could eventually make sense. But anyway, I remember seeing some air-conditioning systems which resort to cold water recirculation, as it has a higher thermal conductivity, so lowering the temperature of water through conventional refrigeration (sort of an oversized fridge) and then pump it through pipes inside a building would still be nearly as effective, consume less energy overall, and not take much moisture out of the air.

But anyway, unless it's a full-EV, most likely the moisture extracted from the air by a conventional air-conditioning system could still be used for water injection in the engine.

In my navy days, the ship used a chill water system for air conditioning. You don't have room for ductwork and that would have compromised flooding and fire damage control. So you get water cold with traditional refrigeration, then pump it through pipes, and then through a radiator. Instead of hot water giving off heat inside the radiator, it's cold water inside absorbing heat. Leaks are also easily recovered and not as dangerous as freon is which was the comman refrigerant when the ship was built. Freon leaks would have found their way to the lowest part of the ship, the engine room, where any flame would turn it into deadly phosgene gas.

[cRiPpLe_rOoStEr]

Besides freon-based air conditioners, maybe you remember ammonia-based absorption systems which used to be common on old fridges. AFAIK now these are only allowed for industrial purposes.

[Piotrsko]

Still have them in fuel fired refrigeration used out in remote locations. Got one in my RV.

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Still have them in fuel fired refrigeration used out in remote locations.

In my country it's no longer so easy to find them, not even in the countryside.

Got one in my RV.

For such specialized usages, a higher price tag becomes a consequence, as such systems become less common. Now that 12-volt compressors became more easily available, most of the new fridges meant to be installed on motor vehicles that I see are fitted with them, instead of relying on an absorption system.