A fund founded by Bill Gates is leading a $20 million investment round in an air conditioning startup that promises to reduce the carbon impact of keeping people cool on a warming planet.
The money will go to market air conditioning units from Blue Frontier, which bases its approach on removing moisture from the air and does most of the work when electricity is cheap and more likely to be green at the source. The company claims to reduce greenhouse gas emissions from air conditioning by 85 percent.
Gates’ Breakthrough Energy Ventures is joined by 2150 Urban Tech Sustainability Fund and VoLo Earth Ventures to invest in Modern Niagara, the commercialization partner that supports Blue Frontier in hopes of bringing the technology to market.
The problems of air conditioning in terms of climate change are twofold. Not only is the electricity needed for air cooling a major source of CO2 emissions – up to 4 percent by some measures – as CO2 emissions warm the planet, but at the same time more people need air conditioning and work is being done harder on the installed air conditioning , more often.
To try to break through this spiraling impact, Blue Frontier has developed a technology based on liquid desiccants – substances that remove moisture from the air. The air is then cooled by indirect evaporative cooling.
The first step in the Blue Frontier process is to concentrate its proprietary liquid desiccants in a brine solution so that it is available to produce air conditioning, a process known as regeneration. Heat is used to concentrate the liquid desiccant, releasing water [PDF] which is recovered for later use to power air conditioning.
It is crucial that after the regeneration phase, the solution is available to cool the air at any time afterwards. In this way, it is designed to store “potential cooling” and thereby take advantage of cheap green electricity and avoid using expensive, more carbon-intensive electricity when demand is higher. It can also help prevent brownouts that have become alarmingly common in the hot California summers.
The system relies on refrigerants and compression in the same way as conventional air conditioning and refrigeration, but they come into play at a different step in the process. Blue Frontier uses refrigerants in a heat pump to control the salt concentrations in the desiccant. Because they are housed in the system, engineers were free to safely select highly flammable refrigerants. It requires less refrigerant than a conventional system, and the refrigerant it uses has a lower impact on greenhouse gas emissions, the company says.
“The refrigerant and refrigerant-carrying equipment never comes into contact with air entering the building or the interior of the building,” Betts told CNBC. “This gives us a huge advantage in using readily available refrigerants that are highly flammable, without compromising the safety of the people in the building.”
The combination of greater efficiency, the ability to smooth out grid demand, and the use of less taxing refrigerants results in a combined reduction in greenhouse gas emissions of between 85 and 87 percent, the company estimates.
Betts said the first products for commercial buildings will be available in 2025, after rolling out to a few pilot sites. ®