Ammonia conference calls for changes to regulations and standard designs, along with a more realistic approach to budgets from specifiers
Experts in the ammonia sector have called for industry input to help make packaged ammonia chillers a more cost effective alternative to HFCs and HFOs.
An expert panel at the 6th IIR Ammonia Conference told delegates that if the ozone, GWP and performance advantages of the refrigerant were complimented by cost-effectiveness in design, the ammonia chiller would be a compelling alternative.
The panel, comprising Andy Pearson of Star Refrigeration, René van Gerwen of Unilever Engineering Services, Predrag Hrnjak of the University of Illinois, and Fons Pennartz of Dutch consultant KWA Bedrijfsadviseurs, said one of the issues was that often chillers were over-engineered, sometimes due to the end-users’ expectation of bespoke designs.
Also attending were representatives of leading manufacturers of ammonia liquid chillers such as JCI Sabroe, GEA Grasso, Mayekawa and RV Cooling Tech, along with manufacturers of components; contractors; end users; and research institutions.
Mr Pearson said: “We must recognise that HFC chillers are the result of decades of development work to drive down to a low price point and it is difficult to compete with that.
However we must also note that end-users are now requiring one additional element of functionality in their chillers, namely that they should have no global warming impact. It is unreasonable to ask for additional functionality yet to expect the same price.”
He said that increased take-up of ammonia chillers would help to drive down the selling price, but it had to remain viable for the manufacturer too. He also noted that end-users ‘must resist the temptation to interfere’.
He said: “When they buy an HFC chiller it is usually the catalogue item with standard components and controls, but when it is an ammonia chiller it is often a bespoke design. We are happy to do this, and it undoubtedly delivers a higher quality product but it is not possible for the price of the high volume, standard chiller.”
Mr van Gerwennoted that designers should use the know-how from the equivalent HFC chillers and ‘steal with integrity and pride’. He said:
“Ammonia chillers should be intrinsically safe, without requirements for complicated permits or licenses from local authorities. The chiller suppliers should facilitate the process for the end-user for obtaining local permits and licenses, if required, and operators should not need extensive additional education and training – it should be fool-proof operation.”
He stressed that standard operating procedures should be supplied and that chiller performance should to be guaranteed by an independent body.
He concluded: “Extra capital costs need to be minimised by stripping all ’nice-to-haves’ from the basic configuration, resulting in ‘like-by-like’ alternatives to HFC chillers.
Extra capital costs need to be justified by proven lower life cycle costs, with acceptable return on investment.”
Mr Hrnjak agreed with his colleagues. He said: “Current ammonia chillers are very expensive due to overdesigned components and system targeting the same expectations for life as in custom made industrial systems.
Compressors should be semi or fully hermetic, light and with full oil return. The charge should be extremely low and we have demonstrated that it can be done.”
He noted that extremely low charge systems on the roof or other well vented locations would allow ammonia vapour to escape freely, almost unnoticed in the vicinity of the chiller as it is lighter than air to.
He concluded; “It is important to establish the total charge of a system that is fully accepted from a safety point of view, in the same way that R290 has a 150 g charge almost universally accepted. Help from organisations and regulating agencies is needed.”
Mr Pennartz said that project budgets were too often based on price, rather than on factors such as sustainability and energy efficiency.
He said: “Even TCO (total cost of ownership) calculations will not convince people to choose for the ammonia chiller, if the budget is based on HFC chiller prices. The ultra-low budget prices at the start prevent the company from buying the more sustainable, energy efficient and more durable solution. In this way the suppliers determine the energy efficiency of companies.
These decisions should therefore not be made on project level but on higher management level where the sustainability goals are formulated.”
He added that ammonia chillers should be safe by design and that the refrigerant charge should not be minimised to obtain “safe chillers”. He said that improved sensor technology should indicate eventual leakages.