NREL in search for energy efficient AC

USA: The USA’s National Renewable Energy Laboratory (NREL) is receiving funding for two projects focused on the use of liquid desiccant in energy efficient air conditioning. 

The NREL is a federally-funded research and development centre specialising in the research and development of renewable energy, energy efficiency, energy systems integration, and sustainable transportation.

Research into a novel membrane absorber for liquid desiccant air conditioning has received $250,000 from the US Department of Energy’s Technology Commercialisation Fund (TCF). A further NREL project to develop an energy-storing HVAC system has received $595,557 from the same fund. 

In both projects, the NREL is partnering with Blue Frontier, a Florida-based company developing smart air conditioning systems combining dew-point-style sensible cooling with liquid desiccant dehumidification.

In the first project, NREL senior research engineer Jason Woods is also partnering with Palo Alto Research Center to establish a new approach for liquid desiccant dehumidification to lower energy use by half, compared to state-of-the-art desiccant-wheel dehumidifiers. It accomplishes this isothermally, without heating or cooling the dehumidified airstream. It can also provide load flexibility for the grid by decoupling energy consumption from air dehumidification.

“Removing moisture from the air is energy intensive, and controlling humidity is an important part of keeping people comfortable in buildings,” Woods said. “Through the TCF funding, we will work to de-risk this technology by producing experimental data that can prove the energy performance of this technology. From there, we will be able to engage with potential HVAC industry partners.”

In this second project, NREL senior mechanical engineer Eric Kozubal is developing an energy-storing efficient HVAC system, said to achieve 80% energy savings by leveraging indirect evaporative air conditioning with separate humidity control. The low-cost, high-density energy storage in the form of liquid desiccant and distilled water also enables more than 12 hours of low-power operation and an all-electric system using NREL’s patented heat-pump-driven desiccant regenerator.

“Existing air conditioning systems need improvements to support a low-carbon future,” Kozubal said. “The world needs an alternative that takes advantage of the emerging growth in renewable energy, has energy storage capabilities, and uses less energy.”

Ultimately, Blue Frontier plans to distribute this technology to building and business owners by offering zero up-front capital cost equipment, lower annual operating and maintenance expenses, backed by knowledgeable technicians to help ensure reliable operation.