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Heat Pumps

  • 27-11-2005 6:32pm
    #1
    Closed Accounts Posts: 148 ✭✭


    Hello, I am looking for a person living in a new house with a heat pump system installed. or someone who knows someone. I am designing a house for my parents. They are a bit dubious about the Heat Pump. My brothers insist you can't go wrong with oil,:confused: and think the heat pump is a con and you will never make your money back.:mad: (They are not construction professionals and as I am a girl, what would I know.:mad: :mad: :mad: I am an Architectural Technition)
    We are building this house for my parents to retire to, they will not have much of an income and I believe spend once now rather than over and over again in the future.

    Mum and Dad want to hear from the horses mouth that this system works.:)


«13

Comments

  • Closed Accounts Posts: 77 ✭✭WILKEL


    I have yet to find out (from someone with direct experience) the actual ongoing cost of running these Heat pumps (electrical cost).
    Anyone prepared to tell us ???


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


    Guys, not totally what you are looking for but getting there.#

    We are building a timber frame and having the collector area for a Direct Expansion geothermal heatpump installed this week. So we should be up and running in January.

    I will help as much as I can, and if it does not work then I will say it as it is.


  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    Why do you not build a passive house?
    Negate the need to heat the house by superinsulating from scratch.
    10w/m2 is about what a passive house needs averaged over the year.
    and 15Kwh/m2 for the annual space heating requirements.
    here is a link to the only company producing standardised Passive houses in Ireland that I know of.
    http://www.scanhome.ie/passive.php


  • Closed Accounts Posts: 77 ✭✭WILKEL


    yop wrote:
    Guys, not totally what you are looking for but getting there.#

    We are building a timber frame and having the collector area for a Direct Expansion geothermal heatpump installed this week. So we should be up and running in January.

    I will help as much as I can, and if it does not work then I will say it as it is.
    Thanks Yop - but surely you have taken into account your running costs before you jump into this project. I am very curious about these running costs as some people say that the electricity cost is low and some critics say it is high - I just have not come across anyone here that has a geothermal type system and had posted up the running costs so as we can compare it to other heating systems running costs.

    Bye the way - the passive house looks very interesting.


  • Registered Users, Registered Users 2 Posts: 2,834 ✭✭✭air


    My boss has a geothermal system installed, I'll ask him for his details and report back.


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  • Registered Users, Registered Users 2 Posts: 712 ✭✭✭GG66


    Cant' add much in the way of direct figures but I spoke with the guy who's doing my timber frame construction about this, he's seen them installed in several places and worked on a lot of eco builds.

    On Geothermal, he says it's all down to how energy efficient the house is. Some people install it with a block built house, mimimum building regs insulation, no passive solar considerations. Naturally their heating requirements are going to be a lot more than someone who adds extra insulation, argon filled windows, etc. So this is one of the main reasons whay there are varying reports of how efficient they are.

    His advice to me was to spend my money on insulation and argon filled windows, place the tubes for underfloor in place, then go a winter without any heating system and see what happens. Once I know what my heating requirements are I can then install what I know I need rather than estimate and spend money on soemthing I may not need.. I can install a wood burning stove to get me through the winter.

    So even if you do get figures from someone on how much it's costing them you can't directly compare unless you know you have similar insulation levels etc.


  • Closed Accounts Posts: 32 tcoen


    From research I've seen try multiplying the square m size of your house bt 2.6 to get the price to heat it with a heat pump in euros e.g 210 sq m house would be around 550 euro in electricity that includes some hot water. 500 - 700 euro would be the range I'd say for that sort of size house


  • Registered Users, Registered Users 2 Posts: 2,199 ✭✭✭Keeks


    Where did this formula come from?


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


    Never came across a formula like that anywhere, have you a source for this?


  • Registered Users, Registered Users 2 Posts: 10 martino


    We installed a Geo-thermal heat pump about two years ago in a new two storey house. The house is quite big at 3000 sq feet so we went with a system of under floor heating downstairs and radiators upstairs. It is a brick house with normal aero-board insulation. We put in double (16 inches) insulation in the attic and 6 inch (instead of 4 inch) rockwool in the partitions upstairs.
    I am finding the heat pump very expensive due to a number of reasons.

    1) The rooms downstairs which we had tiles (kitchen, hall) heat up very quickly and so come up to temperature and don't call for heat after that. The other rooms (sitting room, dining room, study) have a mixture of semi-solid and laminate wood flooring in them and appear to take a lot longer to heat up. This is causing the heat pump to be on a lot longer.

    2) The floors with wood flooring have some air pockets under the floors as the floors are not 100% level and so this is hindering the heat up time as air is a bad conductor of heat.

    It is better this winter (second winter with the system) however we are still looking at our ESB bills being around 400 euro per two months for the winter bills. For a house of this size we would be expecting an ESB bill of around 150 euro per two months during the summer and a little higher in the winter. By this reckoning we would have expected an annual ESB bill of around 1000 euro for the house without a heat pump. At the moment it appears with the heat pump we are looking at (3 x 400) and (3x 150) which is adding up at 1650 euro.

    This is really only a difference of just over a tank of oil which would be a good saving as a house of this size you would be looking at several tanks of oil in a year. The only problem for us is that we have oil heating for the radiators upstairs which is using about a tank of oil in a year.

    By this it doesn't appear if we are making any saving at all (or very little).

    If we were back again I would either have put under floor heating upstairs also, or perhaps not put in a heat pump at all.

    I would expect the cost to drop a little as time goes on as the concrete floors dry out more and more, but the only problem is that the ESB keep putting up their prices all the time.


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  • Closed Accounts Posts: 80 ✭✭smadger


    If I read you right, you're saying that it's costing you about 650 to run the heat pump for the year. To be honest, that sounds fairly reasonable to me, although as you say, I'd imagine there'd be better value to be had in having it heat the whole house instead of just downstairs.

    According to a chart I got from SEI, it would cost about 1800 to heat your house using oil alone. Don't know how reliable that is though, since I have natural gas in my current house. Incidentally, our ESB bill is 650/year for a house half the size of yours for just TV, lights, immersion in summer. No other heating or cooking. So your estimate of 1000 without heating sounds fair to me.


  • Closed Accounts Posts: 77 ✭✭WILKEL


    Thanks Martino,
    that was a very informative piece on heat pumps.
    It looks like you have to take a lot of factors into account and get your house plans well sorted to make them work well.
    From a cost perspective I would imagine that they would want to be costing no more that 60% of the cost of heating the house using oil alone to make any financial sense (after the inital big capital outlay). Rember that the ESB costs are likely to rise just like oil prices if the last few years are anything to go by.
    As a comparsion my house (2500 sq ft - timber frame) uses no more than 1900 litres of oil per year and I dont use electricity to heat water at all - I have a stove for winter and just heat the water from oil in the summer and my ESB bill was an average of €105 per two months for last year.


  • Registered Users, Registered Users 2 Posts: 10 martino


    That is correct although I would probably say the cost of the heat pump is closer to 750/800 a year if you add on a bit for the months of April/September where a bit of heat may be required. This is equivalent to a tank and a half of oil a year. If you add on a tank a year for heating our radiators then that gives 2 and a half tanks per year. I would reckon if we had of just went with an oil burner from the start then two and a half tanks would have did for the year. However with the heat pump we have constant warm rooms downstairs 24 hours a day. If we were to try and get the same heat from an oil burner then you would be talking a serious amount of oil.

    I am delighted with the heat pump but I don't think the savings these salesmen predict is all it's cracked up to be (surprise surprise).

    One thing to remember of course is that ESB prices will rise as oil rises, but it will not drop it's price if oil prices drop which really annoys me.


  • Closed Accounts Posts: 42 alfa


    Very interesting listening to the different running costs for underfloor heating utilising the different forms of heat source (oil v. heatpump).

    My running costs for oil burner on a 2,300 sqft house last year was €2,300.00

    Unfortunately, the oil storage tank installed by the builder is a small 950 l tank and I seem to fill quite frequently.

    I have added 500 sqft of extension onto house this year and naturally my heating costs have increased to the point were I consume 850 litres per month (winter).

    I reckon my oil costs will increase to €3,000 plus this year on average.

    I have been running my heating (u.floor) 24/7 as I have been advised to do so by Services engineers / manufacturer of system but I am currently experimenting with reduced running times to monitor oil usage.

    Am interested because of existing house (external boiler) and lack of access for bore hole, at installing Aerothermal system - Any feedback???

    Thanks

    Alfa

    I am interested to hear from other members on their instal costs for heat pumps.


  • Closed Accounts Posts: 32 tcoen




  • Registered Users, Registered Users 2 Posts: 10 martino


    Hi tcoen,

    Can you re-post the link again as it is missing some of it.

    thanks


  • Registered Users, Registered Users 2 Posts: 2,199 ✭✭✭Keeks


    Fixed the link above ;)


  • Registered Users, Registered Users 2 Posts: 5,430 ✭✭✭megadodge


    Alpha,

    I am just starting to build at the moment and am also interested on hearing about aerothermal heat pumps.

    Got a brochure from Sweco a while back and visited one of the customers mentioned on it and came away quite impressed. He is actually a plumbing contractor himself and half the stuff he was talking about was completely wasted on me, but the bottom line was while running it (aerothermal HP) 24 hours a day all year round for rads (the house is at least 20 years old) he reckons it costs him circa. €20 a week on electricity. I forgot to ask the size of the house, but having been through it, by memory it would be at least 2000 sq. ft. He had it installed at that time for aprox. 18 months and was very happy. Seemed a genuine guy so I've no reason to doubt him.

    Underfloor would obviously be dearer to run and I myself would definitely not have it on 24 hours a day all year round, but the figures don't seem too bad to me. I'm seriously considering it, but want to hear of any other viewpoints on it. Anyone ?

    Also, what's the lowdown on heat recovery systems ?
    Are they worth it (on their own or accompanying) ?


  • Registered Users, Registered Users 2 Posts: 37 Mike_C


    according to Nordic-geothermal sales guy aerothermal is the least efficient system, shallow laid group loops is marginally better, vertical drillhole best, not sure if this is totally accurate


  • Registered Users, Registered Users 2 Posts: 2,834 ✭✭✭air


    That would probably stand to reason all right, the temperature differential between your house and the external loop decreases as you go from air -> shallow ground -> deep ground.
    By this I mean that deeper ground would be warmer than shallower ground which in turn would be warmer than the air (in times of cold weather).
    You are looking for a source that is as close in temperature to your desired household temperature as possible.
    Rivers and lakes work well also apparently.


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  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    Probably true in a purely theoretical sense however the cost of extracting the latent energy may be more than the energy is worth.
    AFAIK the air to water and air are a lot easier to run than the big liquid pumps.
    You only haver to look at the work that the small heatpumps do as opposed to the larger water-water type.


  • Registered Users, Registered Users 2 Posts: 2,834 ✭✭✭air


    Yeah naturally there would be issues with digging that deep hole & moving water up and down a great height (unless thermosiphoning of some sort could be used to help).
    As with all things of this sort your mileage may vary & it is difficult to give general advice as the practicalities involved are usually site specific.


  • Closed Accounts Posts: 5,064 ✭✭✭Gurgle


    Mike_C wrote:
    according to Nordic-geothermal sales guy aerothermal is the least efficient system, shallow laid group loops is marginally better, vertical drillhole best, not sure if this is totally accurate
    I reckon that makes sense for scandanavia where true geothermal is available (the deeper the better) but average air temp is much lower.
    In Ireland though, we have too many miles of bedrock to use true geothermal but a much higher average air temperature. Better to use shallow ground loop (the top 2-3 meters of soil absorb sun heat in summer and hold it) or air-source.


  • Closed Accounts Posts: 964 ✭✭✭Boggle


    The installation cost for a heat pump is very high from what I hear and the cost of ever locating a fault is huge as you effectively have to excavate the whole thing. there is also the requirement for alot of land to lay it out in - although I believe the continent just drill deepe holes and so less space is required. Heating results are known to swing wildly from case to case and it is possible that it will not work too well - although I have not been able to look at the data this is based on yet. Also the running cost for the pump is pretty high from what I've heard (was 600 per year mentioned here somewhere?).

    I know of a company in my home town who are developing a new form of heating that at current levels costs about E15 per week and the guy I talked to reckoned that when it is finished it'll be at less than E10 (although these figures are supposedly for "always on" heating) for a std home so I would do a little investigation into your alternatives before jumping on the geothermal bandwagon as there are safer options available.

    Even though every mech eng I know thinks its the future, I believe it may already be the past...


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


    In terms of highest COP you are talking about Aerothermal (worst), Geothermal, Bore Hole (best).

    That plumbing contractor was hardly in Boyle by any chance?


  • Registered Users, Registered Users 2 Posts: 5,430 ✭✭✭megadodge


    That plumbing contractor was hardly in Boyle by any chance?

    He was indeed.
    Have you a story/warning for me ?


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


    I think he seems ok, I know he works for Sweco (sub contracts) though and dist every other company I mentioned.
    His comments that the system he had was the most efficent on the market and that it beat any geo system I would not agree with as I have contacted a few Universities who did studies on alternative heat (the emails are here somewhere on the DIY boards section I think) about the difference between them all and definately Aerothermal is the least efficent, BUT for people who dont' have the ground available or very poor ground then it is better alternative to oil.


  • Registered Users, Registered Users 2 Posts: 5,430 ✭✭✭megadodge


    Thanks for the reply.

    The lack of ground is exactly my problem though. I just don't have the space and a borehole seems quite expensive.

    Admittedly I'm anything but technical on these matters but the fact that the energy used to pump the brine/water around the garden is saved should surely be a factor when costing ?

    I also noticed when looking at his Pump that the water temperature was around 75 degrees Celsius which is considerably higher than what's mentioned for Geo.

    I am very interested in all this as it's make-up-my-mind time already as I've the timber frame arriving on-site on Monday, so bearing in mind I've very little space outside and I'm very anti-oil would aerothermal seem a good choice ?

    While I'm at it, what are your views on heat recovery systems ? On their own or in conjunction with another heating system ? They're attractive from a health perspective but overall heat, etc. any ideas ?


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


    TO be truthful If I was in your situation I would go with a pellet boiler because I have a mate who has the aerothermal and he is not overly happy with it, different reasons, the main been the supplier, not sweco, having little knowledge of the system, this means that ever time his 500 litre cylinder loses hot water the system kicks in and replenishes this.

    75 degree is not achieved by the ASHP but from the heat exchanger/ heat plate/geser (sp) which is attached to the system, he has rads so he needs the high temperature.

    Ours is running a week now at this stage, is has the heat circulating at 35 degrees c leaving a room temp of 20c, it is stinking hot, but this is also down the to level of insulation and the timber frame.


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  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    It is my belief that any new house should have a HRV system fitted, it makes a huge difference to both the health of the occupants and the building itself.
    I cannot think why anyone would not fit one at the planning/construction stage.
    If you look at it logically, how else is a modern sealed house supposed to breathe? If your doors and windows are airtight to avoid draughts, what allows the free passage of air?
    You could open a window, not very nice this time of year, or Have a vent installed in the wall (draughty)
    Other than that your only option is to install a HRV system.
    Mothman on here has posted a bit about his experience with one.


  • Closed Accounts Posts: 5,064 ✭✭✭Gurgle


    megadodge wrote:
    The lack of ground is exactly my problem though. I just don't have the space and a borehole seems quite expensive.
    AFAIK, they're no good in Ireland. You'll end up with whats basically an electric central heating system which is going to be expensive to run.
    megadodge wrote:
    I also noticed when looking at his Pump that the water temperature was around 75 degrees Celsius which is considerably higher than what's mentioned for Geo.
    Doesn't sound right.
    Do you have the make/model of the pump?
    megadodge wrote:
    would aerothermal seem a good choice ?
    When the air temperature is over 9°C but still cold enough to need the heat on, aerothermal appears to be a good option.
    Do some calculations :)
    http://www.iol.ie/~wicklowweather/Monthly%20Reports/Annual2004graphs.htm


  • Registered Users, Registered Users 2 Posts: 1,508 ✭✭✭Ayla


    This is my first post to this site, and I think there's a lot of really good info on here (there's no better sales pitch than experience).

    My husband and I recently attended the Self Build Exhibition in Belfast and while there got to speak with a number of heat pump companies...what a variety of information we got! It's hard to drudge through the sales jargon and try to decide what is, in fact, the best product out there. I have to say, though, there was a good bit of well-intended but mis-informed sales reps who couldn't say why their companies were better than the others ("because we just are" is one answer we received...needless to say, we didn't talk long with that company).

    I don't know if this is against posting regulations, but I can say that out of all the companies we spoke with, my husband and I were most impressed with the information we received from Sweco. The reps genuinely knew our area (Donegal) and have had a good bit (40 years) of experience building and maintaining heat pumps. All Sweco does is heat pumps (they don't do underfloor systems, etc) and so all of their eggs are in the one metaphorical heat pump basket. Seems to me that they'd know what they're talking about.

    When talking with them, some of the information they gave us did, in fact, conflict with the information from the other companies. However, keeping in mind their experience and knowledge which they supported with facts, my husband and I came to trust their side more than the others.

    All that said, here's what they said (and I'd like to hear from you all as to what you think)...

    If we were living in Scandanavia, where the temps drop considerably below freezing for months on end, geothermal would most definitely be the most effective method of heating the home. However, here in Ireland the worst of the winter temps rarely drop below freezing for more than a few days (in fact, they said the average Donegal temp in January is 6.9), and therefore we can extract heat from the air.

    In fact, according to Sweco, air is much more efficient than ground because of the poor conductivity of the ground. Let me explain...

    The temp of the ground 1-3 metres down takes months to change, so it may retain some of the summer heat until Nov-Dec, but will remain cold until May-June. The geothermal pipes will extract heat from about .5metres away, and because of the same poor conductivity, the temp of the earth in that .5metres will become steadily colder as the winter progresses. It is true that the Irish ground rarely freezes solid, however if the earth around the pipes is becoming colder, and in fact the pipes themselves are eventually covered in a layer of ice, that means the heat pump has to work harder to extract the same amount of heat. This is also why geothermal systems require anti-freeze pumping through the pipes.

    On the other hand, the air temp may get cold (even below freezing at night), but the converse side is that it heats up very quickly every day. Keep in mind the average daily temp even in Jan-Feb is around 8-10. You can install your air pumps on a southern exposure to use the sun's heat as well. The aerothermal pump only works when it has to (when the inside air temp drops), and even the unavoidable icing of the unit can be dealt with much more efficiently. This means the pump doesn't have to work as hard to extract as much heat.

    And as far as initial costs, geothermal is really expensive to install b/c of the piping, whereas aerothermal just has a couple of units to bolt onto the side of the house.

    I know this is a long post, but I thought the info we rec'vd from Sweco was very interesting and I'm really interested in hearing what you all think. My husband and I are doing our own direct-labor self-build this year for our own 2,000 sq. foot home, and we're trying to do the most energy-effecient and logical build possible. Let me know your thoughts.


  • Registered Users, Registered Users 2 Posts: 1,508 ✭✭✭Ayla


    Sorry, me again. Forgot to mention that Sweco said the water in their pump does reach 75C because of the direct exchange system (I started tuning out here b/c it got a bit too technical...just tell me it works).

    However, an important thing that I did remember was that the temp must reach 75 b/c the water has to be sterilized. The other heat pumps get the temps up to 50-60, but then require an immersion to reach 75 for sterilization.

    Any thoughts?


  • Closed Accounts Posts: 5,064 ✭✭✭Gurgle


    Ayla wrote:
    The other heat pumps get the temps up to 50-60, but then require an immersion to reach 75 for sterilization.

    Any thoughts?
    Why would you want sterile water in your central heating?


  • Registered Users, Registered Users 2 Posts: 235 ✭✭slayer91


    Lads,

    Have installed a Sweco Aerothermal System in my house since Dec2005.
    No doubt about but the people involved are very helpful.
    My unit is 14KW (2x7kw Heat pumps). House size is 2300 sq ft. Underfloor down stairs and rads upstairs.
    Things to remember:

    1: Size the Heatpump unit correctly. Check and double that the rating of the heatpump is suitable to cover the heating for your house. Sweco are very helpful in this regard, but by all means double check with appropiate third party.

    2. A 14kw heatpump does not means I am using 14kw of electricity, it is the amount of heat the system can transfer to teh 500l tank. The actual electrical usage is determined by the size of the motors in the heatpumps units. MIne are 1.4kw each. So when the heatpump is running I am using 3kw of electicity. So for every hour they run, it is costing me 51cents( 3 x .136c where 13.6 cents is the cost of a ESB unit of electricity).

    3. However, if you run the system at night and have the ESB night saver rate then you automatically cut the running cost in half.

    4. At the moment, I run the rads for 2 hours in the evenings and charge the underfloor during the night.

    5. The previous poster point is also correct, Sweco are only concern at keeping the water in the tank at a certain temperature, if your underfloor or rads or house insulation is not up to stratch, then it will keep drawing water and this will cut in the heatpump and your costs will increase.

    Have more information but posting is getting a bit long at this stage.:( Will add more later.

    Regards


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  • Closed Accounts Posts: 80 ✭✭smadger


    slayer91 wrote:
    Lads,
    4. At the moment, I run the rads for 2 hours in the evenings and charge the underfloor during the night.
    Interesting - when you say charge during the night, how long do you do this each night and how long does that keep the floor warm for?

    If, say, you had the heating on from 3 am to 7 am, would it then stay warm up to and during the evening? Or would it need to come on again in the evening?

    Cheers,

    Smadger


  • Registered Users, Registered Users 2 Posts: 1,508 ✭✭✭Ayla


    Gurgle wrote:
    Why would you want sterile water in your central heating?

    Good question...my only guess for needing sterilization in your pump is not for the central heating but for the water that'll be used for cleaning, etc. No point washing your dishes w/ water that's germy, right?

    Any other ideas?


  • Registered Users, Registered Users 2 Posts: 425 ✭✭billy_beckham


    Hello Slayer,
    I too have an aerothermal heat pump from Sweco which was installed in our newly built house just before Christmas. We are moved into the house about a month now and i am not really happy with system. For a number of reasons,

    1. Amount of esb being used. Our system is the Sweco 11 so it gives 11kw of heat but uses 2kw to run the heat pump. there are also 3 x 3kw backup immersions. I have two of these off at the moment but the system still is using about 80-90kw/day. Now even allowing for night rate esb(which we have) thats still about E10 a day.

    2. Like you we have ufh downstairs and rads upstairs. I have the ufh running most of the time except for an hour in the morning and evening when i run the rads.I do not run both together as the tank temp drops hugely. But i am not happy with the temp that is being achieved on either floor.

    I have some questions on the system you have and how you run it and we appretiate any help you could give me!

    1. What temp do you supply water to your ufh at?
    2. You say earlier that you only run ufh at night. Is that enough to keep house warm during day?
    3. Are you happy with the radiator part of your central heating ie temp wise?
    4. Sweco sized my heat pump and reccommended the 11kw model with the balance made up by the boosters. Yet you have 14kw for a slightly smaller house??? The figure they used for heat loss was 45w/M2. So 2700ft2 = 250m2. 250 x 45=11.25kw, 2300ft2 = 210m2 x 45 =9.45kw So how come they reccommended a larger pump for your house? What heat loss figure did they use?
    5. In general are yo happy with your system? I spoke to Sweco and they told me that the system will be hard on electricity fo a couple of months until the house is fully dried out. I that your experience?

    Look forward to your reply!


  • Registered Users, Registered Users 2 Posts: 235 ✭✭slayer91


    Hello

    1. What temp do you supply water to your ufh at?

    The temp setpoint for the underfloor is set by the underfloor system and not Sweco. My SWECO setpoint is set at 44 deg, with an hystersis of 2. For me, this means the underfloor runs at an average temp of 35deg


    2. You say earlier that you only run ufh at night. Is that enough to keep house warm during day?

    During mild weather (outside temps above 8degs), this would be enough, however, I would think that the underfloor would need to be boosted by 1-3 hours during the day if temps were lower.



    3. Are you happy with the radiator part of your central heating ie temp wise?

    I would prefer if the rads were hotter, but in fairness Sweco pointed this out from the start. Normal oil biolers heats the rads up to 50-60 deg, Sweco can only heat up to 35-45 deg. To overcome this, I got my plumber to oversize the rads in the bedrooms. Also since the rads are in bedroom so do they need to be on all the time????



    4. Sweco sized my heat pump and reccommended the 11kw model with the balance made up by the boosters. Yet you have 14kw for a slightly smaller house??? The figure they used for heat loss was 45w/M2. So 2700ft2 = 250m2. 250 x 45=11.25kw, 2300ft2 = 210m2 x 45 =9.45kw So how come they reccommended a larger pump for your house? What heat loss figure did they use?

    This is the 64k question that everyone must get right when choosing this type of system. I, too was offered the 11kw unit and used extra insulation in the underfloor and everywhere else in the house. However, just before the system was installed, I have another talk with SWECO and they recommened the change to the 14kw. To be honest, I am glad I followed their advise even though it kind of blew the budget a small bit. The extra heating power is well needed during this cold weather.
    Using the backup heaters is a no no. Alright for very, very cold nights, but I have mine set so that they will not come on. (cold rather than poor!!!!)


    5. In general are yo happy with your system? I spoke to Sweco and they told me that the system will be hard on electricity fo a couple of months until the house is fully dried out. I that your experience?

    In general, yes, I am happy with the system. The system controller could be more intelligent. Yes, it is hard on electricity but careful use of the night time rate can reduce the cost.
    Also remember these months will be the most expensive! once the milder weather starts, the system run time are dramatically reduced. Like any other system, you would need to run it for a least a year to see if it is working out or not.
    My only fear for you is that the system is undersized for for your heating requirements.


    Question for you now, is your domestice hot water very hot, as in, too hot. Did you fit a manually mixing device to this part??

    Regards


  • Registered Users, Registered Users 2 Posts: 5,430 ✭✭✭megadodge


    Slayer, thanks for your input.
    Bottom line though - how much are your ESB bills this time of the year ?

    When it comes down to it, the cost will have a big bearing on whether I go for it or not.


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  • Registered Users, Registered Users 2 Posts: 425 ✭✭billy_beckham


    Hi Slayer,
    many thanks for your reply!
    In relation to the hot water, we got our plumber to fit a thermostatic mixing valve on the hot water from the 500l tank. It mixes the cold supply to the tank with the hot leaving it to give water at about 55-60oC. Would reccommend doing this for two reasons, the water from the tank IS too hot and could scald. Also you would not be drawing heat from the thermal store unneccasarily.

    I guess i am going to just have to play around with my set-up to achieve reasonable running costs!

    Regards.


  • Registered Users, Registered Users 2 Posts: 139 ✭✭VINNIEB


    Not sure if this is allowed but here goes,

    Give these guys a call, HEATLINK IRL, Tullamore, 0506 24062. I am building a house soon, and enquired about Geo-thermal and underfloor heating, they were very helpful explained everything.


  • Closed Accounts Posts: 964 ✭✭✭Boggle


    HI Vinnie - out of interest, how big a house are you building and what will your estimated running cost be per year?


  • Closed Accounts Posts: 12 josephd


    Hi Ragazza,
    Your brothers are right in so far as oil is handy. You won't go wrong with handy in the short term.
    Your parents are understandably dubious with fairly recent heating systems.

    However, if you expect to make an impartial judgement, it will take some time.

    My quick answer is that you should strongly consider putting in a "wood pellet burner", as opposed to an oil burner, or gas burner. Oil as we know it, is gone practically or is/will become, too expensive.
    Wood pellets (sawdust, shavings, and chippings, bound together), is a replenishable source, in so far as a new tree can be grown rapidly, to replace any that is burned.
    Your parents may see some sense in this, but not the speed of growth, with regard to trees currently grown, perhaps. Maybe they do.
    It is also said to be "carbon neutral" (a tree requires co2 gas to grow, and will release it when it is burned. However the new tree will remove it.

    This really means that enviromental taxes/levies, are unlikely to raise the price, but the reverse, possibly (though I doubt we will see prices ever going down).

    The heat pump.
    The consistent claim from manufacturers, or their sales people for the last ten years, is that if you put in one kilowatt of energy(in this case, electricity), then you will get somewhere close to four kw's back.
    Some will say that it is a little lower, which is not bad for that length of time (time for truth).

    If it is anywhere close to that figure, then it is good and efficient.

    However, the efficiencies of a heat pump, oil burner, pellet burner, gas burner or anything; is no use to you.......unless there is a holistic approach, if you will. Sorry, I forgot electrical efficiency (bar heaters, storage heaters, fan heaters, etc.) as well.

    Your electricity bill will likely go up, and a bad house will waste every bit of it. Except a good fridge and microwave oven. lol.

    Back to the heat pump.
    The coils (loops) can go either horizontally or vertically, in your lawn for example. However, there are systems in place in this country(though more common in France) which employ neither a horizontal or vertical looping system. They work overground , and claim to recover energy from the air itself and in conjunction with coolants/refrigerants/liquids with low boiling points. As indeed other heating systems employ, such volatile liquids.

    The investment is large, mainly due to the piping network and isolation valves (which stop or allow water to pass, triggered by thermo stats, and "zone settings"). Modern labor costs, of course don't help.

    That said, the heat pump is a good investment, but not on its own.
    Also, there isin't really a house which requires no heat/energy (around here). If you answer the door, a stiff breeze may well dampen ideals. Lol.

    What can also be deceptive is energy bills which don't factor in the "bags of coal" etc., on top of electricity, oil or gas.

    But I can only imagine your confusion, having being there to some degree. Who does one believe?

    My only suggestion is that you consider an energy specialist, before you plan your house. Look for experience within an Irish climate or the climate of whichever country you live in, and experience in modern Ireland and European implications for the future.

    If you need research, google the University websites of America which at least try to be objective, as they don't try to sell you something, as well as try to not sell you something , lol. But bear in mind, the climatic and fuel differences, which are expensive variables.

    P.S. A friend of mine is currently stressed with the same issue. He went for the overground system, but had and has problems gathering information on it.
    The salesman is setting the stage, it appears.


  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    josephd wrote:
    Also, there isin't really a house which requires no heat/energy (around here). If you answer the door, a stiff breeze may well dampen ideals.
    josephd I would have to disagree with you there, In fact in Galway there is a passive house out in Moycullen, made by Scanhome it is a big place 164sqM.
    The door is actually doubled so that the stiff breeze won't trouble you so much.
    I wonder if people actually think about energy costs when building their own houses? , I mean a person builds a 3000sq ft house and then complains that it is hard and expensive to heat? Get real people if you want to build big at least have the common sense to build in a sustainable manner where you don't need 3000 litres of oil to heat a house per year.


  • Registered Users, Registered Users 2 Posts: 1,508 ✭✭✭Ayla


    CJ -

    Forgive me for being dense, but exactly what part of Josephd's statements were you disagreeing with? I don't think anyone on this site is building a 3000 sq ft home, and if so, I think they're all being realistic about the heating costs, etc. involved. In fact, the point that they're all here, on this site, discussing possible ways to build as efficiently as possible, refutes any argument you were making. I'm not sure I understand the point you were trying to make to this audience...?


  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    Ayla wrote:

    Forgive me for being dense, but exactly what part of Josephd's statements were you disagreeing with? .
    The part that said:Also, there isin't really a house which requires no heat/energy (around here)
    Ok I apologise for the rest of the rant but I will also quote
    I too have an aerothermal heat pump from Sweco which was installed in our newly built house just before Christmas. We are moved into the house about a month now and i am not really happy with system. For a number of reasons,

    1. Amount of esb being used.
    His house is not 3000 sq ft but instead So 2700ft2 = 250m2.
    sorry i was 300 sq ft out.


  • Closed Accounts Posts: 12 josephd


    CJhaughey wrote:
    josephd I would have to disagree with you there, In fact in Galway there is a passive house out in Moycullen, made by Scanhome it is a big place 164sqM.
    The door is actually doubled so that the stiff breeze won't trouble you so much.
    I wonder if people actually think about energy costs when building their own houses? , I mean a person builds a 3000sq ft house and then complains that it is hard and expensive to heat? Get real people if you want to build big at least have the common sense to build in a sustainable manner where you don't need 3000 litres of oil to heat a house per year.

    Hi CJ (that name is familiar?),
    Sorry, what do you mean by "the door is actually doubled". Is it two doors or what?

    Great dicussion, thanks.


  • Registered Users, Registered Users 2 Posts: 14,907 ✭✭✭✭CJhaughey


    Josephd

    Yes there are two doors, one outer and another inner door.
    I find it interesting too.
    If you are in Galway you should try and see it sometime it is a very interesting idea, a big house that needs no or very little input to stay comfortably warm.


  • Registered Users, Registered Users 2 Posts: 139 ✭✭VINNIEB


    House is about 2000 sq ft, Est running cost estimated at E18 per week, based on previous feedback from customers, still waiting on quote.


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