These three refrigerants have been used successfully to heat and cool buildings.
Maryia Tsvirko, technical expert at Belarus-based Mavitech, at ATMO Europe 2017
Photo Credit: Ben Beech
Air, water and ammonia have been successfully and efficiently used as refrigerant in chillers, heat pumps and air-cycle technology to provide heating and cooling in buildings.
These different refrigerant technologies were discussed as alternatives to high-GWP HFCs that are being phased-down under the EU’s F-Gas Regulation, during the ATMOsphere Europe 2017 conference in Berlin, Germany last month.
Warming up and cooling down with ammonia
In 2017 Islington Council in London, UK installed a 1,000 kW two-stage GEA heat pump in the London Underground. The heat pump is now turning the waste heat from a London Underground ventilation shaft into useable heat for a high-rise apartment block in the area, according to Kenneth Hoffmann, product manager (heat pumps) at GEA.
By using two-stage piston compressors it has been possible to achieve a heating COP of above 3.5, according to Hoffmann, thus saving the council money. As the project is next to a residential building, the installation includes an ammonia absorber, which filtrates the air from the emergency extract fan to ensure that the extracted air is ammonia-free. This was an essential part of the installation as more high-rise buildings are planned in the area.
“London is not the only city in Europe with underground trains, so I think you will see a lot more of this type of application in the future.”
– Kenneth Hoffmann, GEA
“London is not the only city in Europe with underground trains, so I think you will see a lot more of this type of application in the future,” he said.
Another country where ammonia HVAC has been used in a large-scale project is Belarus. The United Nations Development Programme (UNDP) is leading the project, for a three-story office building in Minsk.
The ammonia chiller system uses an intermediate coolant to deliver room air conditioning to the 45 offices in the building, according to Selimcan Azizoglu, project manager at UNDP.
Azizoglu explained that the low-charge ammonia (66 kg) chiller system provides 125 kW of cooling for the building.
The hope for Maryia Tsvirko, technical expert at Belarus-based Mavitech, who worked on the project with UNDP and Belarusian contractors CJSC HOLODON and JV RefUnits, is that the project will help “Belarus fulfil its obligations under the Montreal Protocol and help spread natural refrigerants”.
Air, water – the future?
Hayato Sakamoto, assistant manager, engineering & development section, at Japan-based Kawasaki Heavy Industries detailed what Kawasaki calls the ‘world’s-first commercialised water-refrigerant turbo chiller’, dubbed the 'MiZTURBO'.
Sakamoto explained how this product could reduce indirect and direct emissions in Europe. He expects significant energy efficiency gains in Northern European climates with a water-refrigerant chiller as opposed to an HFC one and moderate gains in Southern Europe.
“We expect in approximately one year to bring our product in Europe,” he said.
Ukraine-based UPEC Industrial, using air as the refrigerant, has already demonstrated how air-cycle technology could be used throughout Europe.
The Air-Cycle Turbo Technology (ATT), as UPEC’s Director and Designer-in-Chief Vartan Petrosyants explains, can be used as both a heat pump and as an air-conditioning system for buildings, storage facilities and even vehicles (like railway cars).
UPEC has two types of system on offer: one for stationary and the other for mobile applications.
“Estimated annual electricity power consumption of a railway car is to be reduced by 20 [to] 30% compared with conventional [HFC-based] climate control systems,” Petrosyants said.
The maintenance cost is also lower as the air filters do not need to be changed as often.
The ATT has so far been fitted at a children’s sports complex and a workshop for testing railway bearings in Europe.