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Gavin as ever a sensible analysis and your post has highlighted something I couldn't understand about the defrost cycle, but it's starting to make sense now ;-)

I found this in my inbox this afternoon.
[h=4]Dear Tony,


You may have received the attached letter from MCS regarding thermodynamic solar systems which tells you to contact your CB.

We are not in a position to give any guidance on whether you should continue installing these systems with the intention of receiving RHI payments. As for refrigerant issues raised in the letter we do not certificate safe use of refrigerants and you would need to ensure you meet all the necessary requirements of qualification and/or registration for this type of work.

We would suggest that you cease installation for clients who are hoping to receive RHI. It is likely if the product is accepted under MCS and RHI that they will deem it to be heat pump not solar thermal.

Provided that the issues regarding refrigeration competences are addressed by your business and because the product is approved by the MCS equivalence rule by Keymark, Benchmark will certificate these installations, however we cannot be held responsible or liable for any subsequent decisions and ruling made by DECC or the MCS regarding the status of this type of system in relation to the MCS and RHI and for any loses or claims arising from the installation of them.

As a Certification Body we are extremely perturbed that the MCS felt it was appropriate to direct installers to their CB for guidance on what is a DECC and MCS matter over which we have no control or influence.

Therefore, we recommend that you in fact contact the MCS for clarification.[/h]
 
I'm finding this thread fascinating as I have come up against salesmen from two of the large national pv companies that are now moving body and soul into ThermoDynamics. Both instances were in the last two days.

First one was an end terraced house on mains gas with combi boiler. Two pensioners using no more than £60 per month for gas. This also covered their cooking. Washing machine cold fed....so the amount they were spending on hot tap water can't have been more than £20. Salesman recommended a 250 ltr system for £8500 and said they could earn as much as £1200 a year from RHI.

Second was a large three storey house with 15 year old boiler and hot water tank. Also on mains gas and spending £110 per month on gas. Different salesman. Different company. Recommended a 250 ltr system again this time for £11500. But could do a deal for £9500. Again pushed the RHI.

What was interesting for me is that these were both Internet leads for PV Solar NOT Solar Thermal yet in both cases the sales reps went gung ho for thermodynamic panels. Guess where the big commission cheques are.

Like a lot of the guys here we are staying clear and just watching from the side lines for now.......

And as an aside.....surely a 4kwp system backed up with an Immersun Unit is a much better and more secure bet than any ThermoDynamic panel regardless of whatever RHI is agreed
 
I'm new here and install a little PV but its not my main line of business and only added it as an additional service for my existing client base so don't consider myself an expert.

I was interested in finding out more about thermo dynamics so I got a salesmen round about this but he clearly didn't have much idea about what was required, we have underfloor heating downstairs and was considering this as a whole house solution to "get rid of our gas bill".

He quoted a 250l tank and compressor for the water heating at about £7200 and then quoted about the same or another tank and panel for the heating. He recommended we keep the gas boiler to top up the generated water from 55C to 65C for the rads upstairs. He did say we could swop them for aluminium rads though that run as efficiently at the cooler temperature though. He also said it would qualify for the RFI next year even if fitted now.

Two tanks doesn't sound right to me, how is it suppose to work? Can the "heatpump/compressor unit" be combined with a standard unvented cylinder?

Incidently I found a course that was about £900, took about a week and would be enough to get the fgas certification.
 
I'm new here and install a little PV but its not my main line of business and only added it as an additional service for my existing client base so don't consider myself an expert.

I was interested in finding out more about thermo dynamics so I got a salesmen round about this but he clearly didn't have much idea about what was required, we have underfloor heating downstairs and was considering this as a whole house solution to "get rid of our gas bill".

He quoted a 250l tank and compressor for the water heating at about £7200 and then quoted about the same or another tank and panel for the heating. He recommended we keep the gas boiler to top up the generated water from 55C to 65C for the rads upstairs. He did say we could swop them for aluminium rads though that run as efficiently at the cooler temperature though. He also said it would qualify for the RFI next year even if fitted now.

Two tanks doesn't sound right to me, how is it suppose to work? Can the "heatpump/compressor unit" be combined with a standard unvented cylinder?

Incidently I found a course that was about £900, took about a week and would be enough to get the fgas certification.

Then you have to do unvented water (part G) and your WRAS
 
well you certainly came in swinging on this thread, and seemed intent on tarring everyone with the same brush, but let's move on eh.

I started the thread by posting a letter I received from MCS as a Solar Thermal Installer. I have suspected for some time that people installing this technology were taking a risk. This technology has been wrongly accredited as a solar thermal system and it was never any such thing. The heat pump element of the systems have not been MCS approved therefore if MCS decide that this technology is a heat pump it will carry no approval. To compound matters there is no data available that proves the technology works. So we have a technology with no approval and no test figures hence my post "The Bubble Bursts"


well it'd be easy enough to disprove your statement about the COP falling below 1 theoretically.

The product uses the same technology essentially as any other air source heat pump, and as I said before, doesn't have a fan unit to power. There is no logical reason at all that in a properly set up system the COP of these units won't be at least the same or better than an ASHP operating at the same air temperatures if correctly sized. IF they're cooling the surrounding air faster than the air can be replaced then this will impact on the air temperature and COP, but even in no wind situations natural convection laws should apply, so air will sink as it's cooled drawing in new air over the panels. Even at -10 or lower the COP should be above 1 though, as is the COP on ASHP even when they're using resistive loads to boost the heat, and defrost the unit. I agree it probably won't be much above 1, but I don't see why it would fall to below 1.

There is a fundamental difference between this technology and other Air Source Heat Pumps. With standard ASHP you have a very big fan pulling in large quantities of air and extracting the available heat. With thermodynamics you have a pump pushing a liquid around a circuit. I have seen these panels and the water ways on the panels don't look bigger than 8-10mm (maybe its more?) Anyway, the flow of heat in this type of circuit is nowhere near the amount that can be achieved by a fan unit. In bright sunlight the panel will have sufficient solar gain to give reasonable COP rate but in the dark or at low temperatures the heat gain won't be sufficient to overcome the poor flow rate of the heat transfer medium.

Why would I want to consider this system at all? You fill your roof with horrible black panels and there is no proof that they work. For much less money I could buy an Ecocent unit which is an MCS registered heat pump DHW cylinder combination where there are facts and figures and COP ratings that I can use for comparison purposes.

The whole thing is ridiculous. Nobody should be installing this until there are test results that proves it works.

Oh and I just noticed on another thread that a COP rating of less than 1.0 has been found.
 
Last edited by a moderator:
Both ASHP and Thermodynamic systems use a pump to push fluid around a system to transport low grade heat from an air to liquid heat exchanger to a compressor unit.

The difference is that in an ASHP unit there is a relatively small heat exchanger surface area with a fan forcing a rapid flow of air across it, whereas with the Thermodynamic system there is a large surface area to compensate for the low rate of air flow across the unit.

You're right that there won't be an equivalent flow of heat from these units compared to a big ASHP, but then they don't claim that there will be unless you're using multiple units. The comparison with the ecocent is probably about right.
 
Oh and I just noticed on another thread that a COP rating of less than 1.0 has been found.
You didn't notice that the calculations they used to get to that figure were a load of rubbish though?

Or that I'd given a link to a test report from the lab they're mentioned that gave COP figures of 2.7-3.3 depending on the method used?
 
You didn't notice that the calculations they used to get to that figure were a load of rubbish though?

Or that I'd given a link to a test report from the lab they're mentioned that gave COP figures of 2.7-3.3 depending on the method used?

Gavin - You obviously know your stuff but you repeatedly ignore the several rather large elephants in the room ie.:

1. There is no UK test data proving it works at all
2. It is likely to be re-designated as a heat pump and the heat pump element of the system is not MCS approved
3. With no MCS accreditation there will be no RHI
4. Customers who have bought this will be expecting RHI are almost certainly going to be disapointed and
5. The costs of installing this without RHI means no payback so the whole thing is pointless.

I would be grateful if you could address these fundamental issues rather than picking out elements of my posts that you are able to find some issue with.
 
Gavin - You obviously know your stuff but you repeatedly ignore the several rather large elephants in the room ie.:

1. There is no UK test data proving it works at all
2. It is likely to be re-designated as a heat pump and the heat pump element of the system is not MCS approved
3. With no MCS accreditation there will be no RHI
4. Customers who have bought this will be expecting RHI are almost certainly going to be disapointed and
5. The costs of installing this without RHI means no payback so the whole thing is pointless.

I would be grateful if you could address these fundamental issues rather than picking out elements of my posts that you are able to find some issue with.
I'm not ignoring them, I agree with all of that, I just disagree with people making out that a technology doesn't work just because they don't understand it, and the owners haven't jumped through to correct MCS hoops.

What I'm saying is that we shouldn't thrown the baby out with the bath water here - there's no evidence that the technology doesn't work if used properly, and no technical reason why it shouldn't.

I've recently seen trade prices that I think should make this stuff price competitive with standard solar thermal systems for water heating, and the systems should be a good alternative option particularly where space is limited, or a solution that supplies year round hot water is desirable.
 
What would be far more useful IMO is if the regulatory bodies would actually crack down on the sorts of sales malpractices that are really starting to blight this industry.
 
I agree with Gavin...see my earlier post...the large PV Companies are now targeting thermodynamic panels as the new garlic bread.

But then what can you do......these companies will carry on doing what they do with their doorcan and telecan direct sales teams....so most of these systems will be bought by folks after two or three hour sales pitches...and who won't get competitive quotes or advice......
 
They are not listed on the RHI table of techs ????

am I missing somthing here so that means not RHI payment ????

or are they adding this tech soon
 
I feel this is beginning to descend in to farce. Here we have a bit of kit masquerading as solar thermal that is really a heat pump with a COP of 3 and no mention of what it's likely Seasonal Performance Factor is. So we take one kilowatt of electricity and produce three kilowatts of heat.

With a real solar thermal system we take zero kilowatts of electricity and produce three kilowatts of heat. There is a pump in a solar thermal system you say and that uses electricity. There is a temperature differential so the system will not switch on before it produces more energy than the pump consumes. And yes, in good conditions it can raise the temperature well above 55degC. I make all that a COP of infinity.

To even start measuring the benefit of this technology, it can only be any incremental gain over a standard solar thermal system at times where it would not produce any heat (if there is any gain). It seems to be generally acknowledged on the forum that use for space heating is a non starter. So what exactly is the point of it?

It would appear to have the same carbon intensity and emissions factor as gas, so there is no way DECC are going to include it in the RHI. The best hope would be in off-grid areas where anyone with half a brain would be looking at a proven and effective heat pump technology or maybe biomass which will handle the whole heat load. (or may be stick with what they already have).

There are always people looking for better ways of collecting low grade heat to improve the performance of heat pumps. Some are innovative but none have made the main stream.

In a few years time it is likely this will be viewed as yet another technological cul-de-sac. Think 8 track cassettes and ----el engines.

If it wasn't for all the spivs getting involved in selling the stuff, a more considered and clear headed evaluation could take place without the emotional charge those particular reprobates bring where ever their ugly little heads pop up.
 
Look at this page from one of the solar rogues " The Save Energy Group "

Thermodynamic Heating Systems FAQ

They are very hard sell and have high commission salesmen, a call centre and have all the other unethical angles covered. All subbies so you can guess what their jobs look like!

They are claiming a COP of up to 7 at the bottom of this article !!!!!!!

They also mention a COP of 4.3 to 5.2 during the article and the fact that the system complies with the MCS and will qualify for the RHI.

They have been reported time and time again for miss selling and are still MCS approved so it doesn't matter what any of us think the rogues will continue to flourish.
Until this entire industry is policed properly it appears you can do whatever you like !
 
REAL say they are under resourced so appreciate our input such as reporting issues. However do they want us to go shut the "rogues" down as well.

It angers me that people make a good living from basically ripping people off. someone could argue that's a businessman or salesman selling something that people think they might need and slightly exaggerate the performance !
 
Full page adverts from this company Thermodynamic Hot Water Systems | Solar Panels | Photovoltaic Panels | Solar Electricity Systems

50% Savings on hot water RHPP and 20 years RHI.

If you have time - have a look at the video - fitting instructions for roof hooks at 5minutes 30 seconds are a joy to behold.

Thats got to be the best way of fixing to a tile I have seen in a long while:o_O: at least he used a gob of silicon!!!
 
Ah, I was prepared to be convinced on this - but I just watched the video! OMG LOL and WTF. I'm now fully in the "snake-oil" camp.

Not the best advert IMHO!
 

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