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  1. Ric2013

    Ric2013 Plumber Top Contributor!!

    Starting with the article in the magazine, I would comment that it refers to the advantages of using system additives generally, not advantages of the specific product. Only then does it start to talk about endotherm, but what is the control? Pure tap water, or other leading brand?

    1. Without seeing the scientific methodology and full results, it is hard to comment on the video of the radiator warm up sequence in detail, but it would be interesting to know how the several variables were kept as standard as possible. I would comment that we never see the temperature in the radiators stablise or peak: both radiators still seem to be warming further at the end of the video.

    2. 'Hard science' is used to mean the opposite of science. The scientific method is actually to have a hypothesis and then test this hypothesis to see if there appears to be a set of results supporting that original hypothesis. This is covered at pre-GCSE level, but most of us forget. 'Hard science' does not mean you don't bother to check the outcome because the theory says something must work. The theory about surface tension makes sense to me, but I'd be more interested in seeing the results and what the actual experiment was. After all, running a heating system on urine (its great on the garden too!) might work better than water, until everything starts to go rusty so a one-off test is of limited value. Again, I'd like to see the methodology.

    3. Cynically, I would suggest that the limitation of applicability of an inhibitor might be more down to what boiler manufacturers require (i.e. who they have been sponsored to recommend) than the inhibitor's unique properties. But Endotherm is not claimed to replace inhibitor. So you still need X brand inhibitor to satisfy manufacturer's instructions, presumably. Also, this isn't a reason why installers should use energy-saving heating additives, thus failing to justify the title of the article.

    4. This makes me more likely to want to look into this in greater depth and not write-off the product as snake-oil too soon. Interesting to note the caveat that it has only been tested with condensing boilers and that the result was specific to the cases studied and that '[p]otential performance improvements depend on the current performance, condition and settings of the heating system'. So I need to read the full report to have any idea of the likelyhood of whatever system I wish to dose behaving in the same way, don't I?

    5. 'A quick win'. This puts me off. I fit and install products I believe the customer needs, not products I tell the customer s/he needs because I want to make money selling them. If I put 2 litres of inhibitor in a system (as I did last week) it will be because I believe 1 is insufficient, not just so I can make a mark-up on two bottles. If £36 really does make a 10% saving, I would be using this stuff at home. I suspect most plumbers are the same as me in this respect: while we work to make a living, we aren't in it solely for the money, or for 'a quick win'.

    In conclusion, I am slightly interested, but probably not enough to read the full reports. However, if you can get hold of Enertek test report E3363 and the other reports referred to on the EST webpage relating to EndoTherm, I would be interested. It is very much against this product that much is made of Enertek's scientific testing, but there is not a very obvious web-link to the report, or even an explanation of how the product was tested. I would have put this in place of honour on my website were it my product (but then I don't think like most people, admittedly).

    Sadly the case studies reported on the Endotherm website do not make it clear that there were no other variables. E.g. Skipton High School: the school pupils were involved in the project and were therefore presumably aware that the school was trying to reduce energy use. Could it possibly be that some level of behavioural change was achieved? Reductio ad absurdem, my ratty heating system and draughty house only cost me £300 a year to heat, compared with the previous occupants who spent more. Is it my behaviour or the fact that I installed a Magnaclean? Similarly, how do we know that nothing changed except the heating fluid additive being added? Even degree days aren't a fair test when a building is intermittently occupied and so, presumably, intermittently heated.

    I do think parts of the Endotherm website are beautifully written. For example, a distracted reader of Minimum Energy Efficiency Standards - Central Heating Additive - Energy Saving might be forgiven for taking the idea that Endotherm will improve the EER of a property even though the final sentence would seem to confirm my view that Endotherm will not affect the EER in any way whatsoever, EERs being the blunt instrument that they are.
    Last edited: Jul 19, 2017
  2. Chuck

    Chuck Active Member

    Most of the reports are not available in a complete form, just summaries and cherry-picked results. There is this one, however:

    This may look plausible to the general public but as a piece of technical evidence it doesn't make the cut. I won't waste time pointing out all its technical flaws but here are a couple:

    There were four tests each taking ca an hour and a half performed in one day. That doesn't leave much time for the system and room to re-equilibriate between tests so each could be performed with the same set of initial conditions.

    Whoever wrote the report didn't seem to know the difference between kW, which is a unit of power and kW hr, which is a unit of energy, which doesn't inspire confidence. Professional scientists care about such details.

    The thermometry is not properly described and is critical for this type of experiment. SInce the measurements are not being made at equilibrium the heat transfer to the block will depend on air temperature (i.e. white bulb temperatures), air-flow velocity fields, humidity, and also the gains and losses due to radiation (i.e. black bulb temperatures).

    A typical piece of wood contains a significant proportion of water. When you heat a piece of wood to 50°C some of that water evaporates. Water has, relative to dry wood, a huge heat capacity. So, each time the wood is heated its heat capacity can change. The time for the centre of a block to reach a given temperature is a complicated function of the blocks heat capacity and thermal conductivity. To keep track of what's going on one also needs to monitor and account for evaporation of water from the wood, e.g. by monitoring its weight, and the humidity of the air in the room.

    The only conclusion I draw from this report is that better-controlled tests are needed.
    • Agree Agree x 2
    Last edited: Jul 20, 2017
  3. fixitflav

    fixitflav Member

    Just noticed this thread while searching for something, and if anybody is still interested, below is a post I put a couple of years back on an engineering forum I visit.

    "Anybody familiar with Thermoboost?

    My son had a new boiler fitted, and the guy was singing the praises. He said it worked by lowering the specific heat of the water, and had seen a test where equal volumes of water and water + additive were heated at same rate. The one with got to 33°C, while the water only reached 25°. Then when taken off the heat, the water cooled to 20°, while the other only cooled to 30°. (that was odd for a start, I expected him to say the one with additive cooled quicker, as you’d expect if the heat capacity was lower). He said it saves 30% on heating costs.

    I found the website Thermoboost , it claims 20% saving, but says nothing about how the stuff is supposed to work. I don’t think it’s possible to alter the specific heat of water by an additive. If the additive has lower specific heat it would reduce that of the mixture, but only in proportion, and as the dose rate is 1% of system volume it makes negligible difference even if specific heat of additive is zero. With lower specific heat the liquid would warm up quicker, but also cool quicker, so even if it’s true, it’s not clear to me how it would improve system efficiency.

    You can only get out of the rads the heat that goes in from the fuel, and since modern boilers are >90% efficiency saving 20% looks unlikely to say the least. If some of the rads are blocked with sludge maybe the house isn’t heated adequately, but provided the boiler is OK the cost per BTU or kJ into the rooms doesn’t change. The total cost could be lower, but with a cooler house.

    So all-in-all I’m sceptical, but interested in others’ comments."

    The consensus was it's a con.
  4. johnduffell

    johnduffell Member

    The reason we use water rather than air is the high heat capacity of the water. Lowering it would speed heat up times for the rad but also require higher pumping quantities and larger pipe work.

    I didn't read any further than that, or consider how you would drastically lower the heat capacity of water.
    • Agree Agree x 1

    CHRISX Active Member

    Hello All,

    Thank You very much to all of the Members that replied to this thread - especially to those who wrote very detailed responses - including the replies from yesterday and today.

    I was very sceptical from the point of reading the article [Installer Magazine] about this `Energy Efficiency enhancing additive` but I did not really give it any detailed `Scientific thought`.

    However the well thought out / detailed comments written by some Members did make me think more `Scientifically` about the stated claims for the product - as some messages explained there were some seemingly contradictory claims by the Manufacturer.

    I have really appreciated the interest and involvement of all Members who responded - Thank You all.


  6. johnduffell

    johnduffell Member

    The other thing that occurred to me is that efficiency doesn't have a single meaning in science. It's very abstract in the same way that "percentages" or even "numbers" are.
    So you could indeed improve the"efficiency" of a radiator or other heat exchanger by 15% (eg by directing a fan over it) but that would be efficiency of heat transfer between the fluids, not efficiency of turning gas into usable heat.

    I suspect the technical department proved the former, and the marketing department wrote the latter.
  7. Ric2013

    Ric2013 Plumber Top Contributor!!

    I remember reading some QRL (Quinn Radiators LTD) literature in which they claimed their new radiator was more efficient: the small print showed that the new radiator was more efficient in terms of heat output per lb of steel used in the manufacture of the radiator (and therefore the newer design of radiator had less embodied energy for a given heat output), compared with the standard design. By that yardstick, re-using an old radiator would have been even more 'efficient'.
    What we really are interested in in terms of efficiency is getting the maximum thermal comfort (minimum percentage of people dissatisfied with the room temperature) for the least possible amount of gas.
    • Like Like x 1
    • Agree Agree x 1
  8. fixitflav

    fixitflav Member

    As johnduffell said, it's worth making sure what somebody means by efficiency.
    And if the higher heat output per kg of steel is achieved by using thinner steel hence shorter rad life, overall there might be no improvement
    • Agree Agree x 1
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