The demand for heating and cooling is growing. July 2022 witnessed some of the hottest nighttime American temperatures ever recorded, creating more of a need for air conditioning in homes and businesses. "HVAC systems are really energy intensive. When the weather gets hot and humid, the systems turn on and the grid must react to the load," Kozubal said. "Blue Frontier is a technology that can benefit anyone. The supply air is cool and drier than traditional AC units. This is unique in that it can control a building's temperature and humidity level much better."

They're called Blue Frontier, and they're based in Florida. And they say that they think that their system will be able to cut annual electricity use by between 50 and 80%. And they do say that it will probably be more expensive up front. They're targeting, you know, kind of a payback date of, you know, three to five years or so. That's how long it'll take for the efficiency improvements to kind of pay for themselves through lower energy bills. So for the rest of the lifetime of the unit, then you're kind of, you know, able to see those savings.

Meanwhile Florida-based company Blue Frontier is trialing a commercial air-conditioning system based on both a desiccant (in this case, a liquid salt solution) and evaporative cooling. This design dries the air and then splits it into two adjacent streams, explains the company’s CEO, Daniel Betts. The air in one stream is directly cooled through the reintroduction of moisture and evaporation. The other airstream is kept dry, and it is cooled by being run across a thin aluminum wall that pulls in the cold—but not the humidity—from the first stream. The liquid salt desiccant then runs through a heat pump system to be recharged. To maximize efficiency, the heat pump can be run at night, when the power grid is least stressed, and the desiccant can then be stored for use in the hottest part of the day. Based on the company’s field trials, “we’re looking at 50 to 90 percent reductions in energy consumption,” Betts claims.

Blue Frontier has one promising solution. Its AC system works to reduce humidity and cool the air in separate processes. This matters because maintaining the humidity in a space has as much impact on people’s comfort as managing temperature. But most AC systems prioritize the latter. What’s more, conventional humidity control generates even more greenhouse gases than cooling the air. 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.

Conventional ACs remove heat from indoor air by converting chemicals called refrigerants from gas to liquid and back again and using fans to circulate cool air. They target humidity by cooling the air to the point that water vapor condenses to liquid, then draining it. Their inability to remove humidity independently of cooling makes them inherently inefficient, analysts say. Blue Frontier aims to separate humidity and temperature control using a liquid salt solution that was developed with the National Renewable Energy Laboratory. The solution also stores energy, reducing consumption at peak times, when electricity grids are strained on hot days. The solution is heated up, releasing water and boosting the concentration of salt, making it more absorbent. This can be done when electricity demand is low and effectively stores energy until cooling is needed. After raising $20 million from investors including Breakthrough last year, Blue Frontier is trialing ACs for businesses. "Air conditioning could be a solution to the problem rather than being the problem," said Blue Frontier's CEO, Dr. Daniel Betts