Hydrocarbon limit likely to move to 500 grams by 2018

Hydrocarbon limit likely to move to 500 grams by 2018

A potential hydrocarbon charge increase being considered by an international standards body should create new business opportunities for manufacturers of plug ‘n’ play refrigeration systems.

At a meeting in Dublin, Ireland on 1-2 December, an International Electrotechnical Commission (IEC) working group on household and similar electrical appliances began to prepare a draft to change the charge limit on hydrocarbons. The new limit is expected to change from 150g to 500g; this could shift the market towards bigger, more efficient hydrocarbon cabinets once it is adopted by the full IEC.

Standards from the IEC, a worldwide body that proposes rules governing how to use electrical, electronic and related technologies, influence the development of the market by providing manufacturers and customers with guidelines as to what is safe to use and buy.

The working group was established to suggest changes to the current IEC 60335-2-89 standard that has maintained charge limits for hydrocarbons at 150g, limiting their use.

Countries are; however, free to go beyond what the IEC suggests. The UK has been using charges above 150g in commercial refrigeration units for a while, and is ready to go higher still. The group will be recommending a new maximum flammable refrigerant amount for appliances that will change the IEC standard 60335-2-89.

The EU F-Gas Regulation, which foresees a ban on the use of HFCs with GWP over 150 in plug-in commercial refrigeration as of 2022, is triggering wider uptake of hydrocarbons in this sector. Austrian manufacturer AHT alone has already installed 70,000 such R290 systems in France.

In the US, the Environmental Protection Agency (EPA) only allowed the charge limit to move to 150g in 2011. This is due in part to the fact that the ASHRAE 15 standard bans the use of hydrocarbon refrigerants, except in systems with charge sizes below 150g.

Tests confirms hydrocarbon safety

Resistance to hydrocarbons has come from detractors claiming that their use is unsafe. The IEC working group asked independent stakeholders to carry out safety tests to determine whether these flammability concerns were warranted.
“The charge limit of 150g is completely outdated and unrealistic. It needs to be changed,” said Florian Koch of German environmental group Deutsche Umwelthilfe.

He designed a test together with standards expert Dr. Daniel Colbourne and the IEC working group. German plant and product safety assessor DMT GmbH & Co. KG carried out the test, leaking propane from a commercial refrigeration cabinet to determine whether it would cause a flammable reaction.

“We tried to design a test with the worst-case scenario […]. The leakage holes [in the equipment] are catastrophic, like if somebody hit with them an axe,” Koch said. Unlike in a real supermarket, the test took place in two small rooms of 20m2 and 40m2, making the concentration of propane substantially higher when it started to leak. “A store is around 1,100m 2 or greater,” he said.

Two of the tests – one with 1kg of charge and a condenser on the top in a 40m2 room, and a second with 500g and a condenser on the bottom in a 20m2 room – revealed significant insights. The leak rate was set at 10g, 30g and 60g per minute.

“This would never be the case in reality. Even with the lower leak rate of 10g per minute, this would never happen in a supermarket, as they are hermetically sealed,” Koch said.

The risk was assessed via sensors all over the small room, which revealed even in these extreme conditions, the amount of propane in the room had no chance of becoming flammable, except if the fans were off and the condenser was on the bottom.

“You need to meet safety conditions, like making a top condensing unit, keeping likely leak points up (high), and the fan on,” he urged.

IEC: From implementation to acceptance

The 26 working group members – comprising 13 countries, including Germany, New Zealand, Japan, and the United States – are expected to increase the limit to 500g by 2018.

Koch believes that in fact the limit could go as high as 1,000g, arguing that “then you will have a more efficient system than 500g because you have one refrigerant loop and therefore need fewer components, using less energy”.

“The resistance is because some [in the working group] do not build the machines for the upper limit of 1,000g,” according to Koch. The EPA has also been reluctant to move from 150g in the US and for some applications like water coolers it is still at 80g. If US companies want to sell commercial units globally, however, a new IEC standard would put the EPA under pressure to act.

After Dublin, the working group will collect feedback from other IEC committees prior to adopting the draft as a new industry standard.

Even a change to the 500g-charge limit has the potential to transform the market. The charge limit increase could go a long way to help countries in other parts of the world meet their HFC phase-down requirements under the Montreal Protocol amendment agreed in Kigali in October.