Friday, 4 November 2016

The great phase-out

We wrote about the end of HFCs earlier in the year, but after an amendment to the 1989 Montreal Protocol on Substances that Deplete the Ozone Layer made in October 2016, their days are well and truly numbered. Brought in as a refrigerant gas to replace ozone-depleting CFCs, HFC use will be reduced by 85% across the world by 2045 to cut greenhouse gas emissions. Now the race begins to replace them. With many contenders in the running Simon Lamberton-Pine, Managing Director of DPAC UK, makes the case for the natural alternative 

It all came out of the blue – mainly because we had all forgotten that this was going to happen – hadn’t we? However, what this worldwide news has done has been to heighten the awareness of the fact that air conditioning and refrigeration equipment does indeed contain harmful gases that are damaging our environment.

As consumers (who own refrigerators and air conditioners) we take the equipment for granted. For those of us who have grown up with refrigeration as part of our daily lives, do we give a second thought to the refrigerants being used and the potential impact on the environment? Of course we don’t! As a result, do we even know about the alternative refrigerants available and the resulting changes to the equipment we will need? For those of us involved in Commercial HVAC equipment supply, then we of course are all too aware, and there are plenty of manufacturers now offering alternatives to the conventional HFCs, ourselves included!

HFCs can take a hidden toll on a building's carbon footprint
However, the current main (non HFC) alternatives for the larger buildings/applications are using either Ammonia, CO2 or Propane and they all have different considerations when it comes to selecting these as suitable alternatives to a building's commercial cooling system: Ammonia is highly toxic; it is well suited to large industrial systems, but less cost effective at small and medium sizes. HCs are highly flammable; they are excellent refrigerants for very small hermetically sealed systems but safety used to be an issue for medium and large sizes – although that has now changed somewhat.

For the purpose of this article we are considering the use of R290 (Propane) and its suitability, as well as ensuring safety considerations and precautions are taken into account, as after all this is an inflammable gas! Propane has been used and selected in hundreds of projects for many years, its global warming potential (GWP) vs HFCs is well documented and it is currently the preferred alternative for large and small A/C replacement projects.

Safety is a primary concern where highly inflammable
gases are used
For larger commercial and industrial buildings, equipment is available with duties up to 1,000Kw in single packaged Air Cooled units, which can be mounted externally However, when considering replacing water cooled chillers that are installed inside a building then adequate safety systems have to be considered, (just like commercial gas boilers)

However, getting and transporting Propane for servicing is not that easy and fully licensed suppliers are the best alternative, rather than trying to get a service engineer to transport it! The applications for equipment using R290 (propane) as a natural refrigerant are widespread, covering comfort cooling, process cooling, close control (Data Centre) and general refrigeration (food storage). For example, natural refrigerants are helping the Colruyt Group to save money and deliver its environmental targets, with this leading Belgian retailer moving to hydrocarbons for 100% of its in-store cooling needs

Natural refrigerants avoid the issues concerned with the use of the fluorinated gases. Additionally, these refrigerants offer greater energy efficiency than their fluorinated counterparts – resulting in further reductions in greenhouse gas (GHG) emissions. The most suitable natural alternative in the air-conditioning sector is R290 (propane), which has a low GWP and has high energy efficiency. The large-scale use of R290, however, has been curtailed due to outdated and restrictive safety standards. These were designed decades ago (not taking into account advances in safety features) and over exaggerated concerns related to the inflammable nature of R290 and other hydrocarbon-based refrigerants.

There are some efforts to update international safety standards and make them more accommodating for the use of R290 in all types of air-conditioning systems. However, because of the large commercial interests of the fluorinated gas industry, these efforts are not likely to reach fruition in the near future! Customers who are interested in switching their rooftop-condensing unit from R22 to R290 (propane) sometimes find their efforts get stuck because of a lack of technical knowledge among local installers or technicians, or the absence of standards allowing hydrocarbons in these type of applications.

170 countries agreed to phase-out HFCs at the United Nations in October 2016
Many compressor manufacturers are well advanced into the production of various types using Propane and these should translate into more new equipment as time progresses. One of the biggest challenges is changing the vast quantity of domestic refrigerators, (that is for another article). Additionally, the refrigerants being used in Commercial Refrigeration equipment is now also being considered seriously for replacement with natural refrigeration alternatives. Plenty has been written already about developing nations and their extended phase out schedule and that is a whole other discussion.

UK based M&E Consultants, Contractors and FM Businesses should now be considering Natural Refrigerants as an alternative (particularly if they are involved with replacing older large packaged air cooled units) and in most cases they are far more cost effective, being more efficient and with lower running costs.

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