Industrial scale chillers and heat pumps

Industrial scale production of hydrocarbon chillers has been put into action by Johnson Controls, while that of hydrocarbon heat pumps is expected to follow soon.

Johnson Controls made a presentation at the recent Atmosphere Europe 2011 conference, claiming it has gained valuable experience with hydrocarbon technology installations, such as the one made for the Åarhus University Hospital in Denmark, where both chillers and heat pumps with hydrocarbon refrigerants are currently in operation.

Reported on the Hydrocarbons21 website, the case study from the Åarhus University Hospital project was presented by Alexander Cohr Pachai, technology manager at Johnson Controls, Denmark, on the first day of the ATMOsphere workshop on natural refrigerants.
The Aarhus University Hospital has been gradually expanding the site and needed new chillers to replace out of date R22 chillers. Hydrocarbon refrigerant propane (R290) was chosen for the chillers using a standard product producing cooling at 9/15°C with 35 per cent propylene glycol.

The latest installation also included two heat pumps for which isobutane (R600a) was selected after having evaluated other options including R744. The R600a heat pumps produce hot water at 80°C in wintertime and 70°C in the summer period, while they also deliver the required cooling capacity in wintertime.

One of the challenges was optimising the system to allow the use of semi-hermetic screw compressors. The efficiency was evaluated against other options and was qualified by being the best overall solution for the project.

Johnson Controls is currently looking at other sites where they could provide the same system, and receive some sort of commitment from the market to break the manufacturing problem where suppliers can not scale up production unless market demand is there, while there is no market demand unless the price has reached a competitive level that can only be attained thanks to economies of scale achieved through industrial scale production.

Despite this, the company has already put into action the plan for industrial scale production of R290 chillers and will soon be putting forward industrial scale production of R600a heat pumps. Currently the company is producing industrial scale ammonia heat pumps (72°C) and will be launching ammonia heat pumps (72°C) this year. Industrial scale production of R600a heat pumps will follow shortly after.

Hydrocarbon refrigerants are widely used in Denmark and are offered by several suppliers becoming an accepted technology.

The authorities and fire brigade are used to this type of equipment, with well-understood regulations in place.

The company believes training is the only remaining barrier to a wide roll-out of hydrocarbon technology. The development of guidelines and calculation tools could also help people to overcome psychological barriers.