USA: A project to develop materials that could mitigate the flammability of A2L refrigerants is one of a number of refrigeration-related schemes to benefit from up to $15.8m of DOE funding.

The US Department of Energy’s Building Technologies Office (BTO) is investing the money in 13 projects to drive innovation in early-stage R&D for advanced energy saving building technologies. Six of these are HVACR projects.

Refrigerant manufacturer Arkema is listed as the company looking to develop formulations and additive materials that could mitigate the flammability of “mildly flammable” A2L refrigerant blends.

Nothing else has currently been revealed about the project but refrigerant manufacturers are known to have experimented with a number of flammability suppressants when developing the latest generation refrigerants. Many of these are thought to have been rejected as a result of environmental, energy efficiency or toxicity concerns. Early test samples of the HFO R1234yf, for instance, contained CF3I, a fire suppressant which rendered the refrigerant non-flammable. However, concerns were raised over the fact that CF31 could potentially create an irregular heartbeat and also had a small ozone depletion potential.

Another project receiving funding is for work being carried out by the University of Maryland to develop next-generation reduced charge air-to-refrigerant heat exchangers using non-round tubes. In a paper presented at last year’s Purdue conference, a team from the University of Maryland discussed experimenting with new computer-designed airside tube shapes with small flow channels to minimise or totally eliminate fins.

UTC’s United Technologies Research Center is to receive funding to develop and validate a high-efficiency compressor based roof-top air-conditioning system that uses a sustainable, nontoxic, non-flammable, and high-efficiency refrigerant. Again, no further information has been supplied, but UTC’s research centre has previously received funding for carrying out similar research using water as the refrigerant.

Itself sponsored by the US DOE, the Oak Ridge National Laboratory will receive funding to investigate a novel dehumidification using high frequency mechanical vibration of ultrasonic transducers to “eject” adsorbed water.

Other HVACR projects to receive funding were Stone Mountain Technologies who are looking to validate and analyse a gas-fired absorption heat pump that uses an ammonia-water absorption cycle; Delaware-based company Xergy which is looking at electrochemical compression technology combined with ionic liquid desiccant technology to improve latent and sensible heat loads in air-conditioning systems.