Using R290 in heat pumps: Do the rewards outweigh the risks?
R290 (also known as propane) is being heralded as the heat pump industry’s solution to the F-gas problem.
Unlike synthetic refrigerants, this natural refrigerant is clean, non-toxic and has a tiny global warming potential (GWP). Plus, it’s highly efficient.
The only sticking point? It’s also highly flammable.
At Clade, we were one of the first suppliers of commercial R290 heat pumps. So, you’ve come to the right place if you want to learn more about this fantastic refrigerant.
Here, we’ll share why R290 and flammability shouldn’t be a primary cause for concern (after all, most of us don’t think twice about using natural gas in our homes and business premises!) – and explain why the benefits far outweigh the negatives.
What are the benefits of R290?
At Clade, we’ve been at the front of the curve when it comes to designing, manufacturing and installing R290 heat pumps.
Just a year ago, we were one of the only suppliers of R290 heat pumps. But now, there are many suppliers available. This shows that more and more manufacturers are recognising the benefits of R290 as a refrigerant.
The expansion of natural refrigerants has been exponential and pleasing to see.
R290’s appeal lies in three key areas (although in reality, there are countless reasons to use propane as a refrigerant!).
1. Environmental credentials
First things first, R290 is considered a natural refrigerant. Propane exists in nature and its environmental effects are well-known and understood (unlike many synthetic refrigerants).
Compared to synthetic refrigerants, it also has an incredibly low GWP.
There are a couple of ways of measuring GWP, but you’re looking at a figure of just 3 (when measured over 100 years) or 0.02 (when measured over 20 years).
This is compared to synthetic chemical refrigerants that commonly have GWPs in the several hundreds or even thousands.
With this in mind, R290 has a much smaller effect on climate change than its synthetic counterparts – making it vastly better for the environment.
Plus, it doesn’t release harmful forever chemicals known as PFAS which are present in HFOs.
Not only does this make R290 one of the best refrigerant gases for businesses looking to reduce their carbon footprint. But it’s also a great way to safeguard your heat pump’s longevity in the face of tightening F-gas regulations.
2. Efficiency and temperature
As if its environmental credentials weren’t impressive enough, R290 is also incredibly high-performing as a refrigerant.
To begin with, it has no glide, which is a thermodynamic behaviour found in some synthetic heat pumps.
While glide can be useful in refrigeration, it’s a hindrance when it comes to heat production – making R290 more efficient than synthetic refrigerants at low ambients and high flow temperatures.
Not only that, but R290 is suitable for use in medium to high temperature heat pumps and is the most ideal refrigerant for retrofit projects.
At Clade, our latest R290 heat pump, the Elm, can give you a whopping 80C flow temperature, which is very close to boiler temperatures. This means it can be used as a direct boiler replacement – the first in the UK!
R290 flammability
R290 is flammable, which has previously raised concerns about its safety.
Of course, this refrigerant (like any) needs to be treated with care.
However, we don’t believe that safety is something you need to worry about when it comes to using R290 as a heat pump refrigerant – providing safety measures have been considered and implemented (which we’ll cover in a bit!).
After all, gas risks aren’t a new problem – most buildings still have a natural gas connection, and LPG tanks and bottled gas are common too.
Here are some things that should set your mind to rest when it comes to R290 and flammability.
It’s a small charge
There’s only a relatively small amount of R290 refrigerant in an R290 heat pump – you’d have more propane in a large barbecue cylinder than in one of our heat pumps!
It’s outside
With an R290 heat pump, the refrigerant is situated outside of the building – unlike gas boilers, which involve piping natural gas directly into your building.
There’s a limited range of flammability
R290 is only flammable between 2% and 10% in air. Any less than that, it’s not flammable.
More than that, you won’t be able to ignite it either.
Handling R290 safely: key considerations
Like any refrigerant, R290 needs to be handled with care, and there are some key things to keep in mind when using it in a heat pump system.
At Clade, we have over 35 years of experience working with natural refrigerants like R290.
So, you’ll be in safe hands with our system designers, who’ll know exactly what to watch out for and will be able to make sure your system is set up in a way that’s as safe as possible – for you, your building and its occupants.
Location
First things first, it’s important to be mindful of the unit’s location – which is something that your system designer will be able to advise you on.
In essence, you’ll need to be aware of any sources of ignition, and avoid placing the unit (and, in particular, the safety valve) anywhere there could be a spark risk.
For instance, you’ll want to avoid placing it next to an air handling unit or switch room.
An awareness of the refrigerant’s qualities is also key here. As an example, R290 is actually heavier than air, so if it’s situated next to drains and there’s a potential leak, that’s where the leak will go.
Spark risks
In a similar vein, it’s important to be aware of spark risks when carrying out repairs and maintenance.
For instance, if you’re doing repairs within the copper pipework using a brazing tool, you’ll need to make sure that all the propane is removed from your system, so that it isn’t exposed to the flame.
This is a procedure that involves evacuating the refrigerant correctly, purging with nitrogen and pulling a vacuum – and requires proper training. Bringing us onto…
Training
You should only use correctly trained staff like our engineers here at Clade to design, install and work on your R290 equipment.
Although it’s safe when handled correctly, R290 is a refrigerant that needs to be treated with respect and it requires proper training for it to be dealt with safely.
The difficulty is that there isn’t a well-defined set of rules for dealing with R290 yet, as there is for dealing with natural gas. However, at Clade, we’re at the forefront of the curve when it comes to working with natural refrigerants like R290, and have decades of experience. So, you know you’re in safe hands.
Forced ventilation and leak detection
At Clade, all our units have forced ventilation, and we have leak detection built into all the equipment too.
This consists of a propane sensor inside the compartment where the propane is. Its job is to detect any leaking propane and shut down the piece of equipment.
As we touched upon already, R290 is only flammable between 2% and 10% in air. The sensor acts to shut the system down way before that lower limit of 2% is reached – removing the flammability risk entirely.
The challenge
As you can see, handled correctly and with care, the risks of using R290 in a heat pump are minimal.
However, there is one big challenge in the industry: lack of clarity.
When it comes to natural gas boilers, the rules and regulations are clearly defined.
However, this isn’t the case (yet!) with R290.
This is partly because of the difficulty of regulating for all scenarios.
After all, with natural gas, your boiler is piped into a limitless supply of gas. This means if you get a leak, it will happen forever.
On the other hand, with propane, you have to regulate for lots of different scenarios – from heat pumps to bottles of camping or barbecue gas.
Interestingly enough, you’d actually have more propane in a large barbecue cylinder than you’d have in a Clade heat pump!
With that in mind, R290 currently sits in one of those awkward regulatory spots where the rules aren’t clearly defined.
So, what does this mean?
Well, it just highlights the importance of hiring a team you trust. Look for experience and make sure any engineers working on your equipment can produce appropriate evidence of refrigeration hydrocarbons training – like our engineers here at Clade.
That way, you’ll know you’re in safe hands and that your heat pump refrigerant is being handled with the care it needs.
Talk to us about R290 risks and rewards
Still weighing up whether R290 is the right refrigerant for you?
This natural refrigerant is efficient, clean and non-toxic. Plus, R290 heat pumps can be easily retrofitted in most buildings, making it an ideal fit for businesses around the country.
Yes, it’s flammable. But so is natural gas!
And unlike natural gas, which is being pumped into your home from an effectively limitless supply, an R290 heat pump involves keeping just four or five kilograms of the refrigerant outside, in a sealed box with leak detection measures.
Ultimately, it’s clear that the risks are minimal – and they’re far outweighed by the rewards!
However, it’s your system designer’s job to help you select the best refrigerant for your needs. So, get in touch with us here at Clade to start the ball rolling and have us design, manufacture and install a heat pump system that meets your business’ needs exactly.