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Geothermal....worth it? Recommendations

  • 19-11-2010 6:47pm
    #1
    Registered Users, Registered Users 2 Posts: 5


    Hello,

    I'm new to this website.

    We are trying to decide on whether of not to go with geothermal or oil.....seem to change my mind everyday.

    It's most likely that we'd have underfloor downstairs with carpet and tiles and rads upstairs with concrete floor and carpet. Was advised that rads are best when we are not willing to compromise on the carpet and also that dust mites would have a great time in warm carpet.

    Worried about the price of the geo, will be applying for the mortgage within next few weeks.

    Could anyone who has installed geothermal let me know if you are pleased with it?

    Also, any recommendations for installers in Munster?

    Thanks and sorry for all the questions!

    Cowlips


Comments

  • Moderators, Home & Garden Moderators, Regional Midwest Moderators, Regional West Moderators Posts: 16,724 Mod ✭✭✭✭yop


    Not unless things have changed then I don't think they recommend putting in standard rads with Geothermal.
    There are fan assisted fans, about 200 euro, which I think do work with geo.

    We have it with UFH for going on 5 years and have to say I am happy with it, but of course you will find others who aren't.

    It depends greatly on the installer/pump/insulation and setup.


  • Registered Users, Registered Users 2 Posts: 1,473 ✭✭✭tred


    yop wrote: »
    Not unless things have changed then I don't think they recommend putting in standard rads with Geothermal.
    There are fan assisted fans, about 200 euro, which I think do work with geo.

    We have it with UFH for going on 5 years and have to say I am happy with it, but of course you will find others who aren't.

    It depends greatly on the installer/pump/insulation and setup.

    You can go with Aluminium Rads upstairs with Geo, but id say it works best with underfloor.

    Id agree with Yop, be carefull who you select to install the system. Do your research. A system installed incorrectly is going to cost you down the run. One might say this is the same for all solutions, except the outlay for geo upfront is substantial as well.


  • Registered Users, Registered Users 2 Posts: 86 ✭✭bombadil


    Hi Cowlips

    It was only a matter of time before someone mentioned it but I may as well go ahead.. Electricity! I know 5/6 houses with geothermal installed and in all cases the electricity bill is high...very high, 250-300 euro a month. I know many will argue the case of 'well what would you spend on oil?'... but I just dont think it is worth it, especially considering the initial outlay!


  • Closed Accounts Posts: 118 ✭✭Amateurish


    Bombadil you're being a wee bit vague there. how much of the bill is heat related?
    If even half is related they'd need a 1.5kW pump running 24/7 to run up those bills. the average heat pump might have a performance ratio of 4 to 1 so 6kW constant heating ?? Tell them to close an odd window or turn down the thermostat.
    OP whatever source you use be it oil/geo/solid fuel they all work more efficiently with underfloor since you need water delivered at a lower temp through underfloor. The temperature profile of a room is also much healthier for you.


  • Registered Users, Registered Users 2 Posts: 12,822 ✭✭✭✭galwaytt


    A couple of things...........I don't think Geo is suited to radiator use, as other's have mentioned, either.

    Regarding electricity use, funny thing happened on the way to the bank..........originally, in 2006, I planned to use Geo. When the build was being done, in 2007, I baulked. Too many stories of all sorts of things, and the (then) capital cost, meant I went a different way. But, I had gone and had the 'smart' meter installed anyway.

    Fast forward to last week........I'm thinking now of maybe adding ASHP as a supplementary to my existing, but the ESB thing still bugs me.......an lo-and-behold if I didn't get a letter from ESB telling they had changed my 'smart' meter, as it was faulty, and not only that, but I was being given a credit against my next bill of (approx) €100.

    Which got me to thinking............I wonder how many other's out there may - MAY - also have a dodgy 'smart' meter, and if it's a factor in all the usage stories that abound ? Oh, and, should we just rename them 'dumb' meter's now......... ??

    Ode To The Motorist

    “And my existence, while grotesque and incomprehensible to you, generates funds to the exchequer. You don't want to acknowledge that as truth because, deep down in places you don't talk about at the Green Party, you want me on that road, you need me on that road. We use words like freedom, enjoyment, sport and community. We use these words as the backbone of a life spent instilling those values in our families and loved ones. You use them as a punch line. I have neither the time nor the inclination to explain myself to a man who rises and sleeps under the tax revenue and the very freedom to spend it that I provide, and then questions the manner in which I provide it. I would rather you just said "thank you" and went on your way. Otherwise I suggest you pick up a bus pass and get the ********* ********* off the road” 



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  • Registered Users, Registered Users 2 Posts: 1,357 ✭✭✭jprboy


    galwaytt wrote: »
    .....Fast forward to last week........I'm thinking now of maybe adding ASHP as a supplementary to my existing, but the ESB thing still bugs me.......an lo-and-behold if I didn't get a letter from ESB telling they had changed my 'smart' meter, as it was faulty, and not only that, but I was being given a credit against my next bill of (approx) €100......

    Very interesting - do you know how they calculated the credit? i.e were they able to tell what the correct usage was or was it just an estimate on their part?

    And is there any way that one can independently verify whether or not a meter is faulty??


  • Registered Users, Registered Users 2 Posts: 12,822 ✭✭✭✭galwaytt


    jprboy wrote: »
    Very interesting - do you know how they calculated the credit? i.e were they able to tell what the correct usage was or was it just an estimate on their part?

    And is there any way that one can independently verify whether or not a meter is faulty??

    Good question. From my perspective, there is no way of knowing, and, seeing as they took away the meter.............

    I never complained, but I did wonder sometimes, apart from the laptop and a single light on, my house is usually a Pillar of Darkness, and I would never get my bill below...... €190........so it'll be interesting to see what the next one brings.......

    In short, I can't see a way of finding out, nor a way of checking it even if you did. Which means the ESB could have just stick a pin on a dart board and decided to give me that much - and how could I dispute it ?

    Lot's to be said for analogue instruments now, isn't there........... ? Just look at the 'clocking' industry in modern cars: s/w-driven machines have in fact made errors, and tampering, both easier and more commonplace.

    Ode To The Motorist

    “And my existence, while grotesque and incomprehensible to you, generates funds to the exchequer. You don't want to acknowledge that as truth because, deep down in places you don't talk about at the Green Party, you want me on that road, you need me on that road. We use words like freedom, enjoyment, sport and community. We use these words as the backbone of a life spent instilling those values in our families and loved ones. You use them as a punch line. I have neither the time nor the inclination to explain myself to a man who rises and sleeps under the tax revenue and the very freedom to spend it that I provide, and then questions the manner in which I provide it. I would rather you just said "thank you" and went on your way. Otherwise I suggest you pick up a bus pass and get the ********* ********* off the road” 



  • Registered Users, Registered Users 2 Posts: 295 ✭✭supersparkz


    Lot of people seem to be taking out their geo install in favour of good old fashioned fossil fuel!!

    Its not supposed to be great really.


  • Registered Users, Registered Users 2 Posts: 12,822 ✭✭✭✭galwaytt


    Lot of people seem to be taking out their geo install in favour of good old fashioned fossil fuel!!

    Its not supposed to be great really.

    I don't think it's that simple.

    If you stand an GSHP and ASHP on the ground, it's a good piece of kit. It's the connecting of it, and controlling of it that seems to cause the problems.

    It's not the technology per se, imho.

    Ode To The Motorist

    “And my existence, while grotesque and incomprehensible to you, generates funds to the exchequer. You don't want to acknowledge that as truth because, deep down in places you don't talk about at the Green Party, you want me on that road, you need me on that road. We use words like freedom, enjoyment, sport and community. We use these words as the backbone of a life spent instilling those values in our families and loved ones. You use them as a punch line. I have neither the time nor the inclination to explain myself to a man who rises and sleeps under the tax revenue and the very freedom to spend it that I provide, and then questions the manner in which I provide it. I would rather you just said "thank you" and went on your way. Otherwise I suggest you pick up a bus pass and get the ********* ********* off the road” 



  • Closed Accounts Posts: 7 bluemountainz


    Hi,

    Just wondering what you went for in the end Cowlips? I'm at the stage of a new build where I need to decide on heating system. All along I've been keen on the geo - GSHP, but now due to costs involved I'm not sure if the budget can stretch to it. As per building regs we need to have some sort of 'renewable', so I looked at possibly putting in solar panels instead but tbh these are not really working out much cheaper than the geo route. I'd personally prefer to put more money into making the house air tight, extra insulation etc to minimise the amount of heating required in the first place, but unfortunately this doesn't meet with building regs :(.

    Any advice?


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  • Registered Users, Registered Users 2 Posts: 1,691 ✭✭✭fclauson


    I am going for solar panels - they may not be cheaper to install but they are have very low running costs

    Also you will find that as you super insulate your house the use of GSHP/ASHP will not deliver the renewable you need

    What happens is as you increase insulation the KwH required goes down – but you still need deliver your 10KwM2


  • Registered Users, Registered Users 2 Posts: 12,822 ✭✭✭✭galwaytt


    ... I'd personally prefer to put more money into making the house air tight, extra insulation etc to minimise the amount of heating required in the first place, but unfortunately this doesn't meet with building regs :(.

    Any advice?

    ..tbh, you should be doing that anyway. Putting an (efficient) heat source, into an inefficient house, is pointless.

    By building a higher spec structure in the first place, your renewable contribution will be easier to reach, as the total energy requirement will be lower.

    Apart from that, it's just common sense to do so.

    Ode To The Motorist

    “And my existence, while grotesque and incomprehensible to you, generates funds to the exchequer. You don't want to acknowledge that as truth because, deep down in places you don't talk about at the Green Party, you want me on that road, you need me on that road. We use words like freedom, enjoyment, sport and community. We use these words as the backbone of a life spent instilling those values in our families and loved ones. You use them as a punch line. I have neither the time nor the inclination to explain myself to a man who rises and sleeps under the tax revenue and the very freedom to spend it that I provide, and then questions the manner in which I provide it. I would rather you just said "thank you" and went on your way. Otherwise I suggest you pick up a bus pass and get the ********* ********* off the road” 



  • Registered Users, Registered Users 2 Posts: 1,691 ✭✭✭fclauson


    galwaytt wrote: »
    ...
    By building a higher spec structure in the first place, your renewable contribution will be easier to reach, as the total energy requirement will be lower.

    ...

    Galwaytt - thats not quite true - if you build to regulations then say you heat demand is 96Kwh/M2 - and delivering 10Kw/M2 from a "renewable" is easy - specifically with the heat pump "renewable" :eek:

    But when you get down to say 20Kwh/M2 due to high insulation then a heat pump will not do - you have to go to solar or wood pellet or something else - its the barmy nature of the regs

    also read the discussion at here where I sydthebeat discussed the Part L


  • Registered Users, Registered Users 2 Posts: 12,822 ✭✭✭✭galwaytt


    fclauson wrote: »
    Galwaytt - thats not quite true - if you build to regulations then say you heat demand is 96Kwh/M2 - and delivering 10Kw/M2 from a "renewable" is easy - specifically with the heat pump "renewable" :eek:

    But when you get down to say 20Kwh/M2 due to high insulation then a heat pump will not do - you have to go to solar or wood pellet or something else - its the barmy nature of the regs

    also read the discussion at here where I sydthebeat discussed the Part L

    I see what you mean, but as in your own example, a lot of this may come down to the reading of it, or the 'spirit of the law' as distinct from the 'letter of the law'.

    I'm not a BER assessor, so I'll bow to your better knowledge, but I would be looking at things differently. Firstly, I think a 96kWh/m2 reference is mad. I wouldn't dream of aiming that low - and think 25 - 48 kWh is easily achievable. This being the case I think it's more important that you've lowered the demand of the buiding in toto, rather than reverse-engineer to suit a particular energy technology, just to meet a notional % renewable figure.

    It stands to reason that if, say, you build a 30kWh house, then, to generate the renewable content you require is going to be 'easier' as that actual amount of energy is small. Now, if that means changing technology away from GSHP........then so be it.

    Ultimately, does it matter ?

    This is but one reason why I think the new Part L has over-focussed on some areas (u-value), and not enough on others (airtightness).

    But hey, that's another thread entirely......... :)

    Ode To The Motorist

    “And my existence, while grotesque and incomprehensible to you, generates funds to the exchequer. You don't want to acknowledge that as truth because, deep down in places you don't talk about at the Green Party, you want me on that road, you need me on that road. We use words like freedom, enjoyment, sport and community. We use these words as the backbone of a life spent instilling those values in our families and loved ones. You use them as a punch line. I have neither the time nor the inclination to explain myself to a man who rises and sleeps under the tax revenue and the very freedom to spend it that I provide, and then questions the manner in which I provide it. I would rather you just said "thank you" and went on your way. Otherwise I suggest you pick up a bus pass and get the ********* ********* off the road” 



  • Registered Users, Registered Users 2 Posts: 5,960 ✭✭✭creedp


    galwaytt wrote: »
    I see what you mean, but as in your own example, a lot of this may come down to the reading of it, or the 'spirit of the law' as distinct from the 'letter of the law'.

    I'm not a BER assessor, so I'll bow to your better knowledge, but I would be looking at things differently. Firstly, I think a 96kWh/m2 reference is mad. I wouldn't dream of aiming that low - and think 25 - 48 kWh is easily achievable. This being the case I think it's more important that you've lowered the demand of the buiding in toto, rather than reverse-engineer to suit a particular energy technology, just to meet a notional % renewable figure.

    It stands to reason that if, say, you build a 30kWh house, then, to generate the renewable content you require is going to be 'easier' as that actual amount of energy is small. Now, if that means changing technology away from GSHP........then so be it.

    Ultimately, does it matter ?

    This is but one reason why I think the new Part L has over-focussed on some areas (u-value), and not enough on others (airtightness).

    But hey, that's another thread entirely......... :)


    The problem with Part L is that its a combination of individual components rather than a single coherent system for ensuring new builds reduce their energy demands. The tug of war between reducing energy demand while at the same time having to achieve a constant amount of renewable heating is ridiculous. Last time I looked installing any form of heating is legal yet Part L tries using a hamfisted incoherent constant renewables requirement to make it otherwise. Surely the NB issue here is the low energy requirement for the build. The renewables requirement seems to be a fallback to a different time when house were build to a much lower insulation/airtightness std and by throwing on a couple of solar panels and an auld stove you could comply. We're way beyond that at this point but as usual the Regs haven't cottoned on yet and persist with this antiquated approach. The notion that if you want a particular heating system that you need to increase your energy demand is frankly ludicrous. But hey suck it up and comply - that's the mantra for the little people in this country!


  • Registered Users, Registered Users 2 Posts: 3,189 ✭✭✭mr_edge_to_you


    it was the hardest decision for us on our design but we are in our house now over a year and we are thrilled with it. we have UFH heating upstairs and downstairs, vertical source heatpump and 300liter hot water tank.

    we use the geothermal for all our hot water requirements.

    the heating was absolutely amazing in the winter. house was constantly warm. our full ESB bill for a 2200sq ft house for heating, hot water and household electricity was €1400.

    i would say that it needs to be installed by people who know what they are.

    worth it - a resounding YES.


  • Registered Users, Registered Users 2 Posts: 1,357 ✭✭✭jprboy


    +1 on mr. edge's post.

    Our house is approx 2,600 sq ft and the only difference is that we have a horizontal loop system.

    Our total electricity bill for the year was €1,500 - €1,600 and covered all heating, hot water, lighting and electrical appliances.

    Hoping to cut consumption by replacing all of our 50W GU10 bulbs with much more energy efficient LEDs.


  • Moderators, Home & Garden Moderators Posts: 10,146 Mod ✭✭✭✭BryanF


    it was the hardest decision for us on our design but we are in our house now over a year and we are thrilled with it. we have UFH heating upstairs and downstairs, vertical source heatpump and 300liter hot water tank.

    we use the geothermal for all our hot water requirements.

    the heating was absolutely amazing in the winter. house was constantly warm. our full ESB bill for a 2200sq ft house for heating, hot water and household electricity was €1400.

    i would say that it needs to be installed by people who know what they are.

    worth it - a resounding YES.
    hi, can you give us any breakdown of what your heating/ HW costs are separate from general household Elec are? also would you mind telling us what the geothermal vertical source & pump cost. thanks


  • Registered Users, Registered Users 2 Posts: 458 ✭✭kboc


    I have a well insulated house (150 mm cavity, 150 mm under floor). I installed geo with horizontal ground loops. My house is 4000 sq ft (house 2800sq ft and granny flat 1200 sq ft). The running total for heating and hot water for 6 months Jan 2011 to June 2011 was £222. No joke.

    As eluded to, the key is not the heat pump but the whole package. I have insulation as above, 500 litre hot water tank and (supposedly) one of the most efficient heat pumps on the market. Aparently the secret is in the compressor of the heat pump. This will determine how hard the machine works and thus how much your bills will be.


  • Registered Users, Registered Users 2 Posts: 37 Holla23


    kboc,

    Can you please PM me the type of HP you have and the supplier?

    Thanks!


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  • Registered Users, Registered Users 2 Posts: 587 ✭✭✭JB81


    HI Kboc

    Could you pm me too please, with the type of heat pump?

    Thanks
    JB


  • Registered Users, Registered Users 2 Posts: 180 ✭✭moan 77


    kboc wrote: »
    I have a well insulated house (150 mm cavity, 150 mm under floor). I installed geo with horizontal ground loops. My house is 4000 sq ft (house 2800sq ft and granny flat 1200 sq ft). The running total for heating and hot water for 6 months Jan 2011 to June 2011 was £222. No joke.

    As eluded to, the key is not the heat pump but the whole package. I have insulation as above, 500 litre hot water tank and (supposedly) one of the most efficient heat pumps on the market. Aparently the secret is in the compressor of the heat pump. This will determine how hard the machine works and thus how much your bills will be.

    Hi kboc,
    Could I trouble you for a pm on the systems you've installed in your fine sized home.


  • Registered Users, Registered Users 2 Posts: 1,113 ✭✭✭freddyuk


    kboc wrote: »
    I have a well insulated house (150 mm cavity, 150 mm under floor). I installed geo with horizontal ground loops. My house is 4000 sq ft (house 2800sq ft and granny flat 1200 sq ft). The running total for heating and hot water for 6 months Jan 2011 to June 2011 was £222. No joke.

    As eluded to, the key is not the heat pump but the whole package. I have insulation as above, 500 litre hot water tank and (supposedly) one of the most efficient heat pumps on the market. Aparently the secret is in the compressor of the heat pump. This will determine how hard the machine works and thus how much your bills will be.

    So can you tell me what temperature input you are getting for DHW? If you do not have any immersion backup running what is the highest temperature generated by the HP? Thanks.


  • Registered Users, Registered Users 2 Posts: 458 ✭✭kboc


    freddyuk wrote: »
    So can you tell me what temperature input you are getting for DHW? If you do not have any immersion backup running what is the highest temperature generated by the HP? Thanks.

    as regards my DHW, I have a 500 litre tank. The heat pump heats the hot water up to 45 deg, which does me as my shower has a thermostat at 38 deg and 45 deg is hot enopugh to wash dishes etc. there is an immersion back up, but never used and never will be unless Heat pump breaks down.

    the heat pump works on night time elec to heat DHW and knocks off auto when reaches the 45deg, the comp is set to dedicate only 2 hours of wotking time to the DHW at most during the night and this is always sufficient to heat the whole DHW. One of the main reasons for this my plumber says is that the tank is specially made for heat pumps. the coils inside are 33mm in diamter as opposoed to a normal tank with 25mm diam pipes. Also the coils inside the tank are 4.5 linear metres long, where a normal tank is in the region of half this length. Plus 80mm of insulation on the outside.

    Hope this helps


  • Registered Users, Registered Users 2 Posts: 1,113 ✭✭✭freddyuk


    You have confirmed the problem most have with HP's as the water temperature gets to 45 and most households store DHW at 55-60. The immersion is then required to get up to these temperatures ( and I am guessing yours will have an immersion override for legionella prevention as well to heat up to 60+?).
    You do not say where the temperature is measured from on the tank so we can judge the volume of stored water at that temperature. If you have a smaller tank (as most will) with average family usage then you can understand why the immersion is doing a lot of the work and the bills get higher especially in Winter. It would be interesting to know if you let the HP do it's thing will the temperature get above 45? I think that is about the maximum. The key is you are storing more water at a lower temperature with a large well insulated cylinder and a well insulated house using cooler underfloor heating. Do you have any backup space heating source?


  • Registered Users, Registered Users 2 Posts: 458 ✭✭kboc


    freddyuk wrote: »
    You have confirmed the problem most have with HP's as the water temperature gets to 45 and most households store DHW at 55-60. The immersion is then required to get up to these temperatures ( and I am guessing yours will have an immersion override for legionella prevention as well to heat up to 60+?).
    You do not say where the temperature is measured from on the tank so we can judge the volume of stored water at that temperature. If you have a smaller tank (as most will) with average family usage then you can understand why the immersion is doing a lot of the work and the bills get higher especially in Winter. It would be interesting to know if you let the HP do it's thing will the temperature get above 45? I think that is about the maximum. The key is you are storing more water at a lower temperature with a large well insulated cylinder and a well insulated house using cooler underfloor heating. Do you have any backup space heating source?

    Plumber installed my tank and has install tens if not hundreds of systems exactly the same so i implicvity trust him with regard to temp and legionella.

    Temp measured directly from the tank.

    The HP is programmed to stop once the water reaches 45 deg. It is capable to heat higher than this but will be ineffiecient at this point.

    Back up space heat is a wood burning stove approx 12kw output, has not been lit yet.


  • Registered Users, Registered Users 2 Posts: 5,960 ✭✭✭creedp


    kboc wrote: »
    Plumber installed my tank and has install tens if not hundreds of systems exactly the same so i implicvity trust him with regard to temp and legionella.

    Temp measured directly from the tank.

    The HP is programmed to stop once the water reaches 45 deg. It is capable to heat higher than this but will be ineffiecient at this point.

    Back up space heat is a wood burning stove approx 12kw output, has not been lit yet.


    I'm in same position as Kboc here with HP heating DHW with only immersion to backup. I've been advised that the HP will heat to a max of 50 deg after which the immersion is needed to boost to 60deg. However, heating water to 50 degs with HP will shortens the life span of the HP compressor. Im a bit confused about the legionaires issue because everywhere I look it advises heating DHW to 60 degs on a regular basis to avoid this problem, yet Kboc doesn't and seems to be alive kicking:). Anyone else got views on this issue?


  • Registered Users, Registered Users 2 Posts: 177 ✭✭al2009


    I thought legionnaires was only an issue for warm stagnant water, not something to worry about in a house? Also i have my gas boiler set to about 50c, no timer or override to bring over 60c, i wonder is this just a red herring to defeat sales of heat pumps?:)

    Even in healthcare the main concern is to remove dead legs on pipe work and to achieve water at 65c or above, but the main focus is removing redundant pipe work, indeed one water company pointed out that the wind screen reservoir is a good breeding point for legionnaires.

    alec


  • Registered Users, Registered Users 2 Posts: 1,113 ✭✭✭freddyuk


    At last we have some honest feedback on HP's. Please keep us informed during the Winter. My question about where the temperature was measured relates to where on the the tank - halfway down or 2/3 down as below that it will be cooler and above it will be 45c max. If you have 50% of 300 litres at 45c then you must have enough to service the heat demand of the house? I imagine you will not heat 500 litres in 2 hours using the HP?? so your winter usage would be quite interesting.
    I understand the the legionella setting is a legal requirement and so the immersion should be kicking in every month to kill any potential infection. It would be an automatic program unless it has been overridden. Not sure anyone has been infected in a domestic environment but I could be wrong??


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  • Registered Users, Registered Users 2 Posts: 177 ✭✭al2009


    Freddy

    Most heat pumps monitor the return temperature to the heat pump, if this is set to 45c then the whole of the tank would be taken to be at 45c, the output temperature can be above 60c to achieve this.

    alec


  • Registered Users, Registered Users 2 Posts: 8,352 ✭✭✭threeball


    al2009 wrote: »
    Freddy

    Most heat pumps monitor the return temperature to the heat pump, if this is set to 45c then the whole of the tank would be taken to be at 45c, the output temperature can be above 60c to achieve this.

    alec

    If you have a 15C differential between flow and return the COP would be way down and personally I'd class such an installation as a piece of junk.


  • Registered Users, Registered Users 2 Posts: 8,352 ✭✭✭threeball


    freddyuk wrote: »
    At last we have some honest feedback on HP's. Please keep us informed during the Winter. My question about where the temperature was measured relates to where on the the tank - halfway down or 2/3 down as below that it will be cooler and above it will be 45c max. If you have 50% of 300 litres at 45c then you must have enough to service the heat demand of the house? I imagine you will not heat 500 litres in 2 hours using the HP?? so your winter usage would be quite interesting.
    I understand the the legionella setting is a legal requirement and so the immersion should be kicking in every month to kill any potential infection. It would be an automatic program unless it has been overridden. Not sure anyone has been infected in a domestic environment but I could be wrong??

    The differential in your tank (top to bottom) will depend on the differential across your heat exchanger in the heat pump.
    The factor that determines whether a heatpump would heat 500L of water in two hours would be the kw output of a the heatpump. A 12kw unit would achieve the above without any issues.
    There are fresh water tanks that can avoid the issue of legionella without the requirement to heat the water to 63C.


  • Registered Users, Registered Users 2 Posts: 177 ✭✭al2009


    The point i was making threeball was that a return of 45c means the tank as a whole is at 45c, the theoretical capacity of the heat pump (12kw for eg) is only one factor, flow rate and temperature difference also play a part?

    alec


  • Registered Users, Registered Users 2 Posts: 8,352 ✭✭✭threeball


    A return temp of 45C means the bottom of the tank is at 45C, the top of the tank would depend on what temp the flow was. If flow temp was 60C the top of the tank would be 60C


  • Registered Users, Registered Users 2 Posts: 4,748 ✭✭✭Do-more


    After what length of time does water become stagnant and a potential breeding ground for Legionnaires disease?

    In particular with relation to dead legs, if for example you have a shower which is used only occasionally are there any precautions you can take.

    From the little I have read on the subject it seems that the disease is contacted by inhaling air borne droplets of water which contain the disease.

    I seem to remember an out break a few years back which was tracked down to water standing in a shower head (I think it was Clonmel hospital?).

    In such a case I would assume that it is academic what temperature the water in the tank is if the breeding ground is a shower head that is only occasionally used and once it is turned on the water droplets become air borne before hotter water reaches the shower head?

    I ask because I am considering to use a heat pump (all be it air to water) to heat DHW in a passive built. The indoor temperature in the house should always be around 20 deg C so presumably provides an ideal breeding ground for the disease.

    I don't wish to derail the thread with this discussion so if you think appropriate mods please split.

    invest4deepvalue.com



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  • Registered Users, Registered Users 2 Posts: 5,960 ✭✭✭creedp


    I understand the the legionella setting is a legal requirement and so the immersion should be kicking in every month to kill any potential infection. It would be an automatic program unless it has been overridden. Not sure anyone has been infected in a domestic environment but I could be wrong??

    Is this correct. i.e. is there a legal requirement with respect to dealing with legionella in a domestic setting? In this respect is it also correct that in order to keep the problem at bay it is necessary only to heat to DHW to 60degs once a month? Beyond the problem with the cylinder how does this all work in relation to the existance of dead legs in domestic plumbing systems, particularly seldom used showers, as raised in a number of contributions to this thread? In my case I have asked for a fully programmable immersion switch to be added to my system so that I can program the immersion to kick in a defined intervals to boost the temp to 60 degs - however I was thinking of something like once a week not once a month.

    Its funny because with all the regulations and best practice quoted to me by the plumber, not once did he mention legionella. I was also amused by the response to the request to install a timer for the immersion? What do you want that for - sure your heating system will heat your water. Apparently all I needed was an on/off switch for which to boost the water whenever heating system wasn't on or out of action. I find that strange, surely it should be std to have a programable timer for an immersion. This building lark is like the old TV series 'Tales from the Darkside' at times:)


  • Registered Users, Registered Users 2 Posts: 1,113 ✭✭✭freddyuk




  • Registered Users, Registered Users 2 Posts: 5,960 ✭✭✭creedp


    freddyuk wrote: »


    Had a look at that website but it would appear that the incidences of legionaires disease linked to domestic water systems are extremely rare. It would also seem that even at temps as low as 55deg c legionella will be die in a very short time. So is there a real threat here from DHW systems or is is simply overstated? From a heat pump perspective, it would appear that maintaining DHW at 50deg celsius would not allow legionella to multiply in the DHW cylinder and the odd boost to 60 deg would ensure any legionella in the tank is killed off within 32 min. A once a week boost would probably be sufficient in this context. Is this a reasonable view?


  • Registered Users, Registered Users 2 Posts: 4,748 ✭✭✭Do-more


    Well what I get from that information is that if you are on a public supply which is chlorinated or you add chlorine to your own supply then you have nothing to fear regardless of what temperature your tank is at.

    Is that not correct?

    invest4deepvalue.com



  • Registered Users, Registered Users 2 Posts: 5,960 ✭✭✭creedp


    Do-more wrote: »
    Well what I get from that information is that if you are on a public supply which is chlorinated or you add chlorine to your own supply then you have nothing to fear regardless of what temperature your tank is at.

    Is that not correct?


    Is it common to add chlorine to private well water supplies? I presume if might be for private water schemes but I haven't heard of same done with a one-off private well ... not that that means anything of course:)


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  • Registered Users, Registered Users 2 Posts: 4,748 ✭✭✭Do-more


    Here is a link (pdf) to the UK's guidance document on Legionnaires Disease and Legionella Control.

    The relevant section starts at page 48 of 68.

    In my own situation I will be installing a water softener anyway as I am in a hard water area, it seems that fitting an ionisation unit after the softener should do the trick for controlling the bacteria.

    invest4deepvalue.com



  • Registered Users, Registered Users 2 Posts: 166 ✭✭about2build


    Kboc could you send pm on plumber fitter etc....im in Galway, he mat not be but may know somone in region.
    thanks


  • Registered Users, Registered Users 2 Posts: 4,748 ✭✭✭Do-more


    For further information regarding the Legionnaires Disease, I was at a building show on Saturday and was discussing this with a guy who supplies water softening and filtering equipment and he was suggesting to install an Ultraviolet sterilizer to do the job.

    Seems it's an non issue for me as the public water supply I am on is treated with chlorine dioxide and so should be considered safe.

    invest4deepvalue.com



  • Registered Users, Registered Users 2 Posts: 458 ✭✭kboc


    freddyuk wrote: »
    At last we have some honest feedback on HP's. Please keep us informed during the Winter. My question about where the temperature was measured relates to where on the the tank - halfway down or 2/3 down as below that it will be cooler and above it will be 45c max. If you have 50% of 300 litres at 45c then you must have enough to service the heat demand of the house? I imagine you will not heat 500 litres in 2 hours using the HP?? so your winter usage would be quite interesting.
    I understand the the legionella setting is a legal requirement and so the immersion should be kicking in every month to kill any potential infection. It would be an automatic program unless it has been overridden. Not sure anyone has been infected in a domestic environment but I could be wrong??

    understand now, i think it is haly way on tank, but i have never known the water to be different, probably because my showers all have thermo's on them to 38 deg and the water in tap is hot enough for dishes

    You are quite right, as the first time the HP heated the water it took 2 nights, but it was starting from scratch. In saying that I have filled my bath (old type with feet, quite big) on some occassions and there was enough hot water in the tank the next day, whether all 500 litres were heated to 45 deg, i don't know.


  • Registered Users, Registered Users 2 Posts: 1,113 ✭✭✭freddyuk


    We have great interest in the winter performance when the house demand is at peak and then you need a bath or shower so it will be very interesting to many on here to monitor how you get on. We are big supporters of renewable energy but do not support systems that end up costing end users money because they were misled about winter performance. Summer solar / GSHP is easy but it is the winter we need to design the system for and not break the bank. You can log your solar PV system for all to see the performance online . How many here would do that for their GSHP's? It would be fascinating.


  • Registered Users, Registered Users 2 Posts: 458 ✭✭kboc


    FAO Mods

    I am getting PMed frequently for my info on my HP. I think it would be more benefit if I listed the supplier of the HP with the make and model. Have I permission to do this?

    Can I just add, I have no invovlement in this company, other than them supplying my plumber with the HP for my house.I live 300 miles form them, I gain absolutely nothing commerically from this.


  • Registered Users, Registered Users 2 Posts: 46,545 ✭✭✭✭muffler


    kboc wrote: »
    FAO Mods

    I am getting PMed frequently for my info on my HP. I think it would be more benefit if I listed the supplier of the HP with the make and model. Have I permission to do this?

    Can I just add, I have no invovlement in this company, other than them supplying my plumber with the HP for my house.I live 300 miles form them, I gain absolutely nothing commerically from this.
    PM the details to me first and I'll have a look and talk to the other mods about this.


  • Registered Users, Registered Users 2 Posts: 1,090 ✭✭✭AntrimGlens


    muffler wrote: »
    PM the details to me first and I'll have a look and talk to the other mods about this.

    Hi muffler,
    just came across a thread from Sept 11 which would be relevant to myself and wondering if you had made a decision on allowing kboc to post the details of his geo installer as he was getting continual requests from people. I was hoping to find out who did it and didn't want to be pestering him. Can you advise.
    many thanks


  • Registered Users, Registered Users 2 Posts: 46,545 ✭✭✭✭muffler


    Hi muffler,
    just came across a thread from Sept 11 which would be relevant to myself and wondering if you had made a decision on allowing kboc to post the details of his geo installer as he was getting continual requests from people. I was hoping to find out who did it and didn't want to be pestering him. Can you advise.
    many thanks
    Sorry but he asks the question and then refuses to PM the details. Nothing more I can do in that regard Im afraid.

    You could always send him a PM


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