R32, What’s all the fuss about?
If you are on any of the internet forums or regularly read the trade mags for Air-conditioning and Heat pumps you will see there seems to be a move towards a new refrigerant called R32.
Some of you will be asking do we need a new refrigerant.
What’s wrong with the one we have now(R410A)?
Will it affect me at all?
Why are we changing?
The greenhouse effect (global warming) is caused mostly by CO2 in the environment, but other gases including the current refrigerants we use cause the same effect on the environment. In some cases, the gases we use are much worse for the environment than others.
A 16kW Samsung heat pump contains 2.7kg of R410 refrigerant. If this leaks out into the air this is equivalent to releasing 5.6 tonnes (5600kg) of CO2 into the atmosphere. To put into context, that’s the same amount of CO2 an average car emits in 30000 miles. The Global warming potential of R410A is 2088 kg CO2/kg.
So even though R410 is safe, does not burn and is not poisonous, its GWP (Global Warming Potential) is a problem and any concerned about the environment doesn’t like that, so change must be made. The high GWP refrigerants like R410A are being banned from 2025.
To make the equipment manufacturers keener to change to a new more environmentally sound refrigerant, the availability of R410A has been reduced, by limiting the amount the manufacturers can import into the country.
Refrigerants need to be cheap, environmentally safe, efficient, not poisonous and preferably non-flammable. There are loads of options, but they always have one thing wrong with them.
R290 (propane) is cheap, efficient and plentiful, but it burns like hell. Its GWP is 0
R717 (Ammonia) is efficient but is very poisonous and it eats copper. Its GWP is 0.
R32 (Di-Chloro Methane) is half the cost of R410A (at around £27 a kilo) cheapish, 10% more efficient than R410A, offers higher temperatures, is not poisonous, has a GWP of 675 but, it burns a bit.
So, it looks like R32 is the least bad solution for our industry, it will be regulated and used mostly in small volume systems because the public quite rightly fear flammable refrigerants and people want to be safe in their houses and offices.
If we were to swap refrigerant from R410A to R32 in our Samsung 16kW unit above, the amount of R32 refrigerant we need will be less (typically expect to see 1.9kG in the system). With a GWP of 675kg/CO2e, this means that if this unit leaks it will be responsible for 1300 kg of CO2 equivalent. That’s less than 1/3 as bad as the current refrigerant. So, for the time being, everyone who cares about the world will be happier until the next even better and hopefully safer refrigerant comes along.
The good news is that you as an installing engineer won’t need to change very much, your tools and procedures will be the same with R32 as they were for R410a. R32 only burns if its mixed with air at between 14 to 31% and it needs a big spark to make it burn. The biggest change the engineers will notice is that their refrigerant bottles will have a left-handed thread (flammable gases use left hand threads to stop them getting confused with Nitrogen Oxygen etc).
In Monobloc heat pumps you won’t even notice what refrigerant is in the system, as all the refrigerant is put in in the factory and it should never leak or need topping up. It also has the advantage that all the refrigerant is outside so it’s safe. In split systems where the refrigerant comes into the house, the engineer will need to make sure the refrigerant does not come near any source of ignition. The Fgas guys will need to allow ventilation in their vans and make sure that if the system is installed in any small spaces, the volume of gas does not exceed the limits laid out in EN378.
EN378 says that if all the refrigerant were to leak into a room you CANNOT have more than 0.061kg (61 grams) of refrigerant per metre cubed. So, in our 16kW system with 2.7kG of refrigerant, no part of the system including pipework can go through or into a space less than 44m^3. That would be a room of 18m^2.
R410A will still be available for years to allow old units to be fixed, but the price will rise quickly (it has for all the other old refrigerants. Its currently £57 a kilo and rising fast).
R32 has been used in the far East for a few years now. Currently there are around 10 million systems with R32 in them already.
So, what does the future hold?
This is not the last change of refrigerant, as it is certain that there will be another new one in the next 10 years. The market will dictate if we go for flammable refrigerant housed in safe containers outside or better leak detection and warning devices.
We will update you when we know more, but get used to it R32 as it looks like it’s coming. Ready or not.
R32 is paving the way for flammable refrigerants which have yet to appear on the market. These gases are likely to be widely used and will help shape a greener future for us all. Understanding R32 and how it works can only be good grounding for the future whether you are an engineer, system designer or end user.
The Samsung Gen 6 and Hitachi R32 Heat pumps will be here in late October 2019.