Researchers from the Polytechnic University of Valencia in Spain and heating specialist Saunier Duval, a unit of Germany-based Vaillant Group, have developed a new residential heat pump based on natural refrigerants.
The device uses propane as a refrigerant, which allows for high energy efficiency, while keeping carbon dioxide emissions to almost zero.
“Our heat pump can heat homes completely environmentally friendly, without emitting carbon dioxide into the atmosphere. In addition, its high-efficiency energy allows it to be classified as renewable energy, by pumping energy from the environment”, said researcher José Gonzalvez.
According to the scientists, the heat pump is able to generate domestic water at up to 75 C, a value which they describe as impossible to achieve for conventional heat pumps.
“In addition, it can be installed not only in new buildings but also to replace gas boilers in existing buildings. It also allows applying the anti-legionella treatment without the need for external support,” Gonzalvez explained.
The heat pump purportedly has a high efficiency of A+++ and can produce 6.49 kWh of heat for each kilowatt-hour of power it consumes. It is also capable of producing 4.43 kWh of domestic hot water for each kilowatt-hour of consumed power.
“In the technological developments that have been carried out to date, it has been possible to achieve energy efficiencies similar to those achieved with our refrigerants, with a high atmospheric heating power,” said Gonzalvez. “To do this, we performed an analysis on the best configuration of the vapor compression cycle adapted to the refrigerant used – propane – thus minimizing the amount used and optimizing the control parameters of the equipment.”
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The researchers did not provide any additional technical details about the device.
According to Germany's Fraunhofer Institute for Solar Energy Systems ISE, the Polytechnic University of Valencia is currently developing a tool for predictive simulations with its IMST-Art software for the simulation and design of refrigeration equipment. The German institute is also developing refrigeration circuits for heat pumps, which will be able to operate as efficiently as possible with low amounts of climate-friendly refrigerant propane.
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Sounds promising but need more technical data.
Producing water at 75C with a COP 4.43 is easy to do in the Spanish summer. Not so easy in the German winter.
Looks like an air sourced pump.
Capable? In the hot Spanish summer maybe when you can get hot water directly from solar heating panels without a heat pump, I’d like to see its performance in the winter below 0C.
How hot will it heat the water when its 40 below outside?
Using carbon dioxide as a refrigerant, Sanden heat pumps can pull heat out of -20F air, and at warmer temperatures it is spec’d to heat water up to 175F at 4.5 COP.
Yes – naturally – COP drops and is not ideal at -20F, but the goal here is not to electrify Northern Saskatchewan, it’s to get a good average seasonal efficiency available for the majority of the humans on the planet, and electrify everything. As long as only 2-3 months of the year are cold enough to significantly lower COP, the net costs here (especially with added solar power) will still be dramatically reduced vs. natural gas.. all as carbon emissions are cut 50-100% depending on local power generation and climate. Just add more solar panels for decades of free heat!
My house came with a 100-year old heat battery infrastructure – it uses ~100 year old steam radiators with hot water instead of steam. The total stored energy is significant, they stay warm for hours after the boiler shuts off.. meaning I could probably use a smaller nighttime battery, and have less trouble bridging the nighttime power gap with a smaller chemical battery, and heat the house with 100% solar.
I agree Tony, skeptical on performance here in Ontario Canada where we regularly see -20Deg C (even -40 in some areas) for at least 2 months a year. But I like where this is going and will keep an eye on the research. Makes me hopeful to build my dream rural home without relying on $1000+ per month propane to stay warm. A solar panelled roof with battery storage + heat pump would be ideal. Expensive up front, but…
Why does everything have to be a one shot solution? So it doesn’t work in Germany. So what. Not everyone in the worlds live in Germany. This would be excellent for Australia, South, Central and most of North America, Africa and large parts of Asia, but lets not develop it because it won’t work in one small part of the world.
Absolutely – ours struggles in Scottish winters and eats up electricity.
But can it do it on a cold and rainy Tuesday night in Stoke?
Liquid propane is not a new medium for a refrigerant. R600 is in common usage in domestic refrigerators these days, and has been for a few yrs. Calor Gas first introduced the concept maybe 10yrs ago or more, stating it’s categorisation as a hydro-carbon gas, and thus inflammable. This has put a lot of people & organisations off using equipment so adapted, as they could present a fire risk. However, it is recognised as a very efficient medium, with useful characteristics.
Right Paul, and if the propane is used in a mono-block air-to-water heat pump, all the propane is outside and their is less of it than in a split system. Also it can be installed by a plumber and with 75 C water will work with existing high-temp radiation systems to reduce the conversion cost.
As you all said , aspirational aka an air source pump
I leave in Ireland, with temperatures not like Spain.
I wonder what the performance would be then.
Good luck getting this in the U.S.
Propane has been used in the past as a refrigerant.
Because it’s highly flammable and under high pressure, the regulators won’t allow it.
Actually r290 (a hydrocarbon based refrigerant) is allowed but the charge can only be about a third of a pound. Basically it is limited to refrigerators, ice makers and the like. Maybe a very small window unit but I would think even a 5kbtu unit would need more than that.
Interested to learn more and hear if this technology also provides cooling, and at what efficiency.
It definitely can. The only problem is that it is flammable and the regulators in the US limit the size of such systems as a result. Pretty much limited to refrigerators and ice makers.
In fact r290/propane can be retrofitted into pretty much any existing ac system. It’s a bad idea though as more than one ac tech has been killed working on a system that they thought was non flammable when in fact someone put propane it.
It sounds really interesting and promising. The problem is closer they get to freezing there’s not so much heat to recover, my conservatory heat pump needs a heater assistance less than 5degrees to stop it cutting out. However any environmental savings is a saving.
Can we put this 6.49 kwh of heat into some like 20% electric generator, get 1.3 kwh of electricity, put it back to this heat pump and finally build perpetuum mobile?
I would just like to point out that it is IMPOSSIBLE to generate 6.5 kwh of heat with an input of 1 kwh because it violates the first and second laws of thermodynamics.
It is IMPOSSIBLE.
the 1st and 2nd laws of thermodynamics doesn’t cover two/three heat sýstems combined. Every commercial airconditioner is performing today with at least COP of 3.5.
Therefore, an improved COP of 6.5 is possible as well, but actually the article mentions a COP of 4.4
It doesn’t GENERATE the heat, it extracts it from another fluid, air or water. The 1.3KW is used to do the work of “pumping” heat energy against the thermal gradient. Just like pumping water uphill.
That’s because it isn’t ‘generating’ heat – it is pumping heat from outside to inside. Just like your air conditioner cools your house by rejecting the heat to the outdoor space, this heat pump heats your conditioned space by cooling the unconditioned space. Yes, there’s heat even in freezing air, although the colder the source, the lower the coefficient of performance. If your indoor space is +15 and your outdoor temp is -10, you extract 5 degrees of heat, returning +20 indoors and -15 outdoors, repeating the cycle to add heat to your conditioned side. Conventionally these systems have a COP of 3-4, meaning they are able to ‘pump’ 3-4 kwh of heat per 1kwh of electricity used. A jump to a coefficient of performance of over 6 is a major advancement.
Heat pumps do not generate heat. They transfer heat. They consume energy (electrical) to transfer energy(thermal). They don’t consume electrical energy to convert it to thermal. Therefore it is absolutely possible to transfer 6.4kWh of thermal energy by only consuming 1kWh of electrical energy
not writing what is the performance at ambient temp close to 0⁰C, is an attempt to hide the real story.
Heat pumps lose efficiency as the latent heat in the source fluid decreases.
Put a bucket of water in the sun. Close the top. See how hot it gets. Sun power is incredible.
the 1st and 2nd laws of thermodynamics doesn’t cover two/three heat sýstems combined. Every commercial airconditioner is performing today with at least COP of 3.5.
Therefore, an improved COP of 6.5 is possible as well, but actually the article mentions a COP of 4.4
I agree! Indoor air quality tends to be worse in the winter months because there is often no flow of fresh air from the outside, meaning allergens stay trapped inside.
How can it produce 6.49KWh heat energy from One KWh of energy?
Something is missing here… because it breaks the 1st law of Thermodynamics!!!
Heat pumps do not produce energy. They use electrical energy to transfer thermal energy that already exists out there, into the house. With heat pumps you “pay” only the price for transferring an amount of energy that already exists.
It doesn’t it is a heat pump. some industrial heat pumps have a COP of 12. i.e. produce 12kWh of heat for one kWh of electrical energy
Hi. In a small brewery in Manchester I looked at all this in 1993 94. Published in RAC Magazine. Southampton University and many others John Cantor Heat pumps wrote letters of support. The fire test on a domestic fridge was better with propane. Lower density propane lest liquid volume.
I also Published in brewers guardian about Ammonia small units. Best refrigerant of all. ( thermodynamics and other. )