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Did wood pellet systems never catch on?

  • 12-09-2019 2:33pm
    #1
    Registered Users, Registered Users 2 Posts: 33,995 ✭✭✭✭


    I know a few people who have installed the slack burners in their garages, and they are happy with them. Always having the house at a constant temperature and hot water too.

    I was tempted by one in the past, but I don't think that coal has a future as a heat source, and it will either be taxed out of use, or banned in the coming years.

    I did a quick search here, and there seems to be a lack of threads on wood pellet systems.

    Did they never catch on? I remember reading that they were expensive to run, but surely they should have a market for them for domestic heating?

    Anyone on here got one?


«1

Comments

  • Closed Accounts Posts: 3,292 ✭✭✭TheBoyConor


    Too expensive, troublesome and need too much tending.

    Get an air to water heat pump system instead and once it's in you'll never have to even think about it again all going well.


  • Registered Users, Registered Users 2 Posts: 33,995 ✭✭✭✭NIMAN


    How do they compare money wise?

    Why would a wood pellet burner require tending? What about a hopper to hold several days worth of fuel? And surely burning pellets leaves very little ash or waste?


  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    Pretty brutal from an emissions point of view to heat your house by burning wood. Almost as bad as coal or turf.


  • Closed Accounts Posts: 3,292 ✭✭✭TheBoyConor


    Good quality pellets are stupidly expensive. And a lot of the pellets available are poor quality dusty rubbish. But people buy the cheap stuff and it causes problems with the boiler. Then they get a bad reputation for reliability.

    And they need tending because you have to remove ash periodically. Then you have to top up the pellets every few days. It is mot terribly onerous but still, people have better things to be doing that fluting around with ashes and pellets.

    Basically they are not worth the hassle.

    I'm telling you lad. Air to water head pump will slot in instead of your boiler and maybe upgrade your radiators and insulation and you will be away with it.


  • Registered Users, Registered Users 2 Posts: 33,995 ✭✭✭✭NIMAN


    I'm telling you lad. Air to water head pump will slot in instead of your boiler and maybe upgrade your radiators and insulation and you will be away with it.

    Thanks for the feedback.

    You got an A2W pump yourself?

    What sort of money are you talking to install such a system in a house of 2200sq ft? (appreciate that insulation might need redoing as well).


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  • Registered Users Posts: 3 mrjohntobin


    I installed a wood pellet boiler in 2008 and I'm going to replace it with air to water. Why?
    - Filling pellets is easy, just press the button once or twice a week. Scrape out the residue in the combustion chamber once a week.
    - Ash builds up throughout the boiler and it needs to be turned off, mostly disassembled, and cleaned 3-4 times per year. This is about 4 hours work each time now that I'm practiced and have tools.
    - Ash builds up, so the flow of air decreases, so pellets don't burn properly and leave more ash => downward spiral. The boiler goes from OK to choked and not heating the house in about 2 weeks.
    - The pellet store needs to be cleaned out once per year because pellet dust builds up around the auger and eventually the auger isn't feeding pellets, it's just spinning dust. It takes about 3 hours to clean now that I'm practiced and have an ash vac and other tools. You need the store to be completely empty to clean it, so there's stress about timing the order so that you don't run out of pellets. I have a large store for >3 tons and a smaller intermediate store for 0.5 tons, so I have that much to burn when the large store is empty.
    - No supplier wants to deliver less than 3 tons, so you're always waiting until you've nearly run out to order.
    - My garage is covered in soot and ash. If you put it in your garage, build an enclosure around it, but leave enough space all around for yourself to hunker down and work on it.
    - My well-insulated-for-2008 house needs 5 tons of pellets per year, and pellets are around 350 euro per ton from the suppliers who will deliver to me.
    - Pellets change if you change suppliers and sometimes between deliveries from the same supplier. Then you're trying to adjust your boiler to burn cleanly, not have too much ash, not have unburnt pellet stubs, ... it's painful. The documentation I have just says "adjust the air and feed of pellets" :(
    - There's one person in the country who services my boiler, so if anything goes wrong that I can't deal with - like a firebrick breaking - I can be waiting several days. In the winter. In a cold house.

    The only reason I haven't replaced it with oil is that I care about the environment, so I'm holding out for air to water.


  • Registered Users, Registered Users 2 Posts: 12,136 ✭✭✭✭KCross


    That sounds like a right dose tbh!

    Heat pump is infinitely better than that. Power it up and forget about it, fully automated 365 days of the year and no ordering fuel required.

    Im sure the pellet boiler system was alot cheaper day 1 but you have to put a value on your time too.


  • Registered Users, Registered Users 2 Posts: 12,136 ✭✭✭✭KCross


    unkel wrote: »
    Pretty brutal from an emissions point of view to heat your house by burning wood. Almost as bad as coal or turf.

    Is it?

    I thought the idea of these pellet systems is that it would be from sustainable sources so somewhat renewable.... coal/turf cannot be replenished so way worse I would have thought?


  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    There's enough cheap coal / turf on earth to last us for a thousand years. So sustainable enough (as way before we run out of them, we will have 100% really renewable zero emissions electricity). We don't / shouldn't use it though because of the emissions that are generated when burning it. Same as burning wood.


  • Registered Users, Registered Users 2 Posts: 2,489 ✭✭✭bennyineire


    unkel wrote: »
    There's enough cheap coal / turf on earth to last us for a thousand years. So sustainable enough (as way before we run out of them, we will have 100% really renewable zero emissions electricity). We don't / shouldn't use it though because of the emissions that are generated when burning it. Same as burning wood.

    Eh I don't think you get it. For every wood pellet you burn it's been refrown so you are not adding to the carbon emissions except for your initial first burn and of course the delivery. Wood pellets come from renewable willow tree forests. Willow only takes about 5 years to grow and harvest and as soon as you harvest 1 tree you grow another one. Coal however takes thousands years to form


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  • Registered Users, Registered Users 2 Posts: 12,136 ✭✭✭✭KCross


    unkel wrote: »
    There's enough cheap coal / turf on earth to last us for a thousand years. So sustainable enough....

    That’s not the definition of sustainable in the context of climate.

    Previous poster made my point for me.


  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    Eh I don't think you get it. For every wood pellet you burn it's been refrown so you are not adding to the carbon emissions

    I wasn't talking about carbon emissions. NOx, SOx and particulates are the cancer causing nasties that shouldn't be near people.


  • Moderators, Home & Garden Moderators Posts: 10,141 Mod ✭✭✭✭BryanF


    How does the Embodied energy of a wood fueled boiler compare to a heat pump (factoring Irish poor design/BER and primary energy factor) has there been any peer reviewed studies?

    Other than inner city urban areas, is timber ‘timber’ nox & Sox, worse than Irish power stations burning a mix of gas/oil/peat for elec generation, some of which runs heat pumps?


  • Closed Accounts Posts: 3,292 ✭✭✭TheBoyConor


    Pellets is fine for large commercial permises like a hotel or nursing home. They have the funds to have a maintenance contractor or more often now they don't buy the boiler and fuel as such, they but heating as a service. They enter a contract with a service provider and buy heat from them and pay by the kWhr used. The contractor installs, runs, maintains and repairs the system in good order so it is up to them to keep it running efficient. And they are a specialist so it is no bother to them. Client has no involvement only to pay the bill for the kWhrs of heat used.
    And the beauty of it is that if the boiler is crap or breaks down, the contractor still has to provide heat so they are obliged to replace it with another boiler, or maybe heat pump or oil boiler or whatever at their own expense. Most of these crowds will have a mobile oil boiler in a traler that can be hooked up to provide heat while the main boiler is out of action. All that matters is that they provide the heat required by the premises.
    That is the only scenario that a pellet boiler would make sense in my view. Completely farm out the hassle of dealing with it.

    For a domestic system, you just want minimal involvement and no hassle.


  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    BryanF wrote: »
    is timber ‘timber’ nox & Sox, worse than Irish power stations burning a mix of gas/oil/peat for elec generation, some of which runs heat pumps?

    Irish power stations run mainly on gas. Almost zero oil / peat / coal these days. And I guess for the nasty emissions gas must be cleaner than timber (haven't checked this, but someone will hopefully show some figures)

    And of course at night time when heat pumps run to avail of cheap night rate electricity, up to 75% of electricity production in Ireland is from wind (zero emissions)


  • Registered Users, Registered Users 2 Posts: 33,995 ✭✭✭✭NIMAN


    I notice that Energia in their radio adverts say they sell electricity produced by "100% renewable energy".

    It can't all be coming from wind turbines, so assume gas is considered renewable?


  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005


    NIMAN wrote: »
    I notice that Energia in their radio adverts say they sell electricity produced by "100% renewable energy".

    It can't all be coming from wind turbines, so assume gas is considered renewable?

    The gas power stations have to run at full power to back up the renewable energy. So they could be getting the energy from 100% renewable sources, it gets priority, but the fossil sources are still spinning away as a back up.

    Renewable energies dirty secret is that it doesn't replace fossil fuel and apparently its releasing massive amounts of a more potent green house gas. Look at the trouble South Australia had till they got a massive battery pack, which hasn't been replicated.


  • Registered Users, Registered Users 2 Posts: 9,814 ✭✭✭antoinolachtnai


    Del2005 wrote: »
    The gas power stations have to run at full power to back up the renewable energy. So they could be getting the energy from 100% renewable sources, it gets priority, but the fossil sources are still spinning away as a back up.

    Renewable energies dirty secret is that it doesn't replace fossil fuel and apparently its releasing massive amounts of a more potent green house gas. Look at the trouble South Australia had till they got a massive battery pack, which hasn't been replicated.

    Energia and other suppliers buy guarantees of origin for the same amount of electricity that their customers consume. This is what lets them claim their electricity is renewable.

    https://www.sem-o.com/markets/guarantees-of-origin/

    Gas generated electricity is not renewable. Gas is a fossil fuel.

    Give us more details about this ‘more potent greenhouse gas’ you speak of?


  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005


    Energia and other suppliers buy guarantees of origin for the same amount of electricity that their customers consume. This is what lets them claim their electricity is renewable.

    https://www.sem-o.com/markets/guarantees-of-origin/

    Gas generated electricity is not renewable. Gas is a fossil fuel.

    Every unit of renewable is currently backed up by a fossil fuel unit. So while they are buying renewable energy, and they have to buy it before fossil, there's no corresponding reduction in fossil fuel plants output as they have to maintain a spinning reserve to cover the unreliable renewables.
    Give us more details about this ‘more potent greenhouse gas’ you speak of?

    https://www.bbc.com/news/science-environment-49567197


  • Registered Users, Registered Users 2 Posts: 9,814 ✭✭✭antoinolachtnai


    Del2005 wrote: »
    Every unit of renewable is currently backed up by a fossil fuel unit. So while they are buying renewable energy, and they have to buy it before fossil, there's no corresponding reduction in fossil fuel plants output as they have to maintain a spinning reserve to cover the unreliable renewables.

    Can you show us proof that there is no reduction in fossil plants’ output as a result of wind turbines generating? I would be surprised if you could prove this.

    What does this have to do with renewable energy in particular?


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  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    Del2005 wrote: »
    Every unit of renewable is currently backed up by a fossil fuel unit. So while they are buying renewable energy, and they have to buy it before fossil, there's no corresponding reduction in fossil fuel plants output as they have to maintain a spinning reserve to cover the unreliable renewables.

    This is untrue. The biggest electricity power station this country has ever had (Moneypoint - coal) has effectively been pretty much shut down for nearly a year now. Without any new gas electricity power stations coming on board. The ESB could do this mainly because of the increased production of renewable energy (wind) and the greater reliance we have on interconnectors.


  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005





    What does this have to do with renewable energy in particular?

    A massive increase in a highly potent greenhouse gas from renewable energy installations and you want to know what it has to do with renewable energy?


  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005


    unkel wrote: »
    This is untrue. The biggest electricity power station this country has ever had (Moneypoint - coal) has effectively been pretty much shut down for nearly a year now. Without any new gas electricity power stations coming on board. The ESB could do this mainly because of the increased production of renewable energy (wind) and the greater reliance we have on interconnectors.

    If we can get upto 85% of our power from renewable when it's bright and windy where does it come from on a calm night?


  • Registered Users, Registered Users 2 Posts: 5,783 ✭✭✭eddhorse


    Del2005 wrote: »
    If we can get upto 85% of our power from renewable when it's bright and windy where does it come from on a calm night?

    Battery storage


  • Registered Users, Registered Users 2 Posts: 9,814 ✭✭✭antoinolachtnai


    Del2005 wrote: »
    A massive increase in a highly potent greenhouse gas from renewable energy installations and you want to know what it has to do with renewable energy?

    This relates to electrical generation of all types, not renewables in particular. I believe the major issue in Ireland was in relation to a station at Moneypoint.


  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005


    This relates to electrical generation of all types, not renewables in particular. I believe the major issue in Ireland was in relation to a station at Moneypoint.

    They said that it's from increase in renewables and that they are trying to build new wind farms without the gas. If its not an issue why are they replacing the best gas for the job?


  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    eddhorse wrote: »
    Battery storage

    +1

    In the widest possible definition of a battery to include:

    - actual chemical battery storage (still very expensive)
    - storage in the batteries of EVs (V2G / V2H) and home attached batteries
    - pumped hydro
    - interconnectors
    - production of hydrogen

    etc.


  • Registered Users, Registered Users 2 Posts: 2,830 ✭✭✭air


    A friend and his father both have the same pellet boiler stove.

    They've been flawless for about 10 years he says.

    I think one or other needed a new ceramic igniter once.
    Other than that the only issue was some dusty pellets hampering ignition a few times. Cleaning the hopper fixed that.

    His main complaint is having to fill it.


  • Registered Users, Registered Users 2 Posts: 12,136 ✭✭✭✭KCross


    air wrote: »
    His main complaint is having to fill it.

    I'd say that and the price of the pellets.

    As per someones earlier post...
    My well-insulated-for-2008 house needs 5 tons of pellets per year, and pellets are around 350 euro per ton

    Thats not at all cheap to run.

    With relatively only a few suppliers, its ripe for price gouging.


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  • Registered Users, Registered Users 2 Posts: 2,830 ✭✭✭air


    Personally I think we should be moving away from burning anything.
    Biofuels impact on land use, require transport and in urban areas there's bound to be particulate emissions impacting on human health.
    Far less than a wood stove though (or so I believe).

    Natural gas with increasing biogas/syngas should be the last to go.


  • Registered Users, Registered Users 2 Posts: 65,710 ✭✭✭✭unkel
    Chauffe, Marcel, chauffe!


    KCross wrote: »
    My well-insulated-for-2008 house needs 5 tons of pellets per year, and pellets are around 350 euro per ton

    That's insane. My brutally badly built and very poorly insulated 2000 house costs less than that to heat per year (with gas) and that's including my DHW hot water heating and we have an open fire place with a gas fire in it that herself lights most evenings, even in August!


  • Registered Users, Registered Users 2 Posts: 8,580 ✭✭✭jmreire


    Too expensive, troublesome and need too much tending.

    Get an air to water heat pump system instead and once it's in you'll never have to even think about it again all going well.

    Conor, could you give any ideas about cost's, installation etc? How well insulated would the house have to be? Would it be necessary ( for example) to have to dig up floors, to install piping, additional insulation etc? And as for the unit itself... how does it actually work? Is it something that would replace the current oil burner I have in the shed? I mean take out the oil burner, and replace it with the heat unit?


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    The problem with heat pumps is the massive cost to buy.

    Also, People think once they're installed they run forever.


    What kind of warranty do you get and if it breaks how long will it take someone to come out and fix it ? parts availability etc ?

    I was looking to get quote for water to water HP using the well water, cop 7:1, amazing, but just can't get the galway company to come out and take a look and give opinion as to whether it's worth my while or not.

    This would be retrofit , heating existing rads, problem is the Well is on the opposite side of the house to where the oil boiler is now.

    Air to Air cheaper but only about 4:1 at best. I have night rate electricity so I don't know , current cost is about 1200 a year in oil not having it on all day, with HP you have it on 24x7 so its going to cost but at least the cost can be offset in the future with solar pv and FIT.

    The real issue is getting it installed right and warranty and if it breaks in 10 years and costs too much to fix that's a lot of money !


  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005


    forever.


    What kind of warranty do you get and if it breaks how long will it take someone to come out and fix it ? parts availability etc ?

    Why are people in this country so transfixed on the warranty a company offers when we have some of the best consumer protection in the world? If it breaks you have the Sale of Goods and Supply of Services Act(SoGaSoSA) to get it fixed.

    Parts are an issue for any product but the SoGaSA means that the company has very few excuses for not rectifying your problem.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    The issue is how long the warranty is and how much it will cost to fix if it breaks.

    Heat pumps are crazy expensive.

    I can't even get the damn company to come out and give me a quote ffs imagine trying to get them to come out and fix it ?

    This could be the same if it breaks and no law in the land is worth crap when the house is cold and you're battling for your "consumer protection"


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  • Registered Users, Registered Users 2 Posts: 19,031 ✭✭✭✭Del2005


    The issue is how long the warranty is and how much it will cost to fix if it breaks.

    Heat pumps are crazy expensive.

    I can't even get the damn company to come out and give me a quote ffs imagine trying to get them to come out and fix it ?

    This could be the same if it breaks and no law in the land is worth crap when the house is cold and you're battling for your "consumer protection"

    You can get your money back under consumer protection if the company is as bad as you describe. What do you get with a warranty if the company is as bad as you describe?


  • Registered Users, Registered Users 2 Posts: 14,452 ✭✭✭✭ednwireland


    watch the electricity cost of heat pumps the only people i know have electricity bills higher than my oil and electric put together


  • Registered Users, Registered Users 2 Posts: 2,830 ✭✭✭air


    Plenty of people had heat pumps installed into new builds from the 2000s on.
    In very many cases the installers didn't know what they were doing and went bust soon afterwards, leaving customers without any support. Consumer protection legislation isn't of much use then.
    Added to this the majority of houses at the time had substandard insulation and air tightness. The prevailing building regulations were awful as was the standard of construction. Furthermore consumers didn't understand how best to utilise their heat pumps, which wasn't surprising when the fly by night installers didn't either.

    All these factors combined to give them a bad name in Ireland and indeed caused high running costs in many cases.

    Move forward to the current day, insulation & building standards have (thankfully) improved to the point that the total heat demand of new homes is now much lower. As a result it's much harder to justify the increased capital costs of ground source vs air source HPs.

    Yes, they are more efficient but you're just not consuming enough units to make back the additional capital cost by the difference between the cost per unit on each system.

    Personally if I was doing a new build I would focus on insulation and probably aim from somewhere between current regs and passive standards. A cheap 5kW oil burner and/or resistive heating for the rare occasions when supplementary heat would be required then.


  • Registered Users, Registered Users 2 Posts: 12,136 ✭✭✭✭KCross


    air wrote: »
    Plenty of people had heat pumps installed into new builds from the 2000s on.
    In very many cases the installers didn't know what they were doing and went bust soon afterwards, leaving customers without any support. Consumer protection legislation isn't of much use then.
    Added to this the majority of houses at the time had substandard insulation and air tightness. The prevailing building regulations were awful as was the standard of construction. Furthermore consumers didn't understand how best to utilise their heat pumps, which wasn't surprising when the fly by night installers didn't either.

    All these factors combined to give them a bad name in Ireland and indeed caused high running costs in many cases.

    +1

    air wrote: »
    Move forward to the current day, insulation & building standards have (thankfully) improved to the point that the total heat demand of new homes is now much lower. As a result it's much harder to justify the increased capital costs of ground source vs air source HPs.

    Yes, they are more efficient but you're just not consuming enough units to make back the additional capital cost by the difference between the cost per unit on each system.

    Its a reasonable argument but the lifespan of the system has to be taken into account too. All things being equal Ground source will last alot longer than an A2W system. That has value and is usually forgotten about when people are deciding what to put in. They are usually stretched on budget already and opt for the cheaper install. Its short sighted imo but needs must at times.

    Also, the very time you need your heat pump to be efficient (very cold outside) is when an A2W system is running at its least efficient so you need to watch those COP figures that are quoted in their literature. Ground source is not effected in the same way.

    air wrote: »
    Personally if I was doing a new build I would focus on insulation and probably aim from somewhere between current regs and passive standards. A cheap 5kW oil burner and/or resistive heating for the rare occasions when supplementary heat would be required then.

    Passive standard (or close to it) is the holy grail but if it was easy then all new houses would have it. I suspect it costs a fortune to do it?


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  • Registered Users, Registered Users 2 Posts: 2,830 ✭✭✭air


    I'm in almost total agreement with that all of that Kcross.

    However the collector in a GSHP should last 100 years plus but the pump itself will still require replacement occasionally.

    Obviously it should last a lot longer all things being equal as it's indoors and there are no fragile evaporators being battered by the elements.

    Additional insulation is not that expensive in the grand scheme of things and by being pragmatic about the approach good results can be achieved relatively economically.

    I will point out that the vast majority of houses being built now still don't meet building regulations from what I see on sites in terms of wall & roof build-up, foundation type etc.
    They're much improved from 15 years ago at the same time at least.

    Things like insulated foundations are only starting to be seen here now despite being a mature technology. They are cheaper than strip foundations with far superior thermal (& likely structural) performance.

    You're correct on the efficiency of ASHP being worst when you need it most which is why I wouldn't fit one (in a new build) I'd build for passive performance down to about 5C and use a low capital cost backup system below that.

    I still see very poor installation practices by contractors installing UFH too, pipe spaced too wide and no knowledge of proper pipe layouts.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    The heliotherm pumps are supposed to me one of the best in the world they got a good reputation in Germany I was told.

    However a cop of 4:1 etc is meaningless if that's only down to what, maybe 10 Deg C ?

    I say the heat pump heater in the Nissan Leaf, consumed little energy until about 5 deg C and from 3 and below the consumption increased considerably, granted, the HP is a car is much smaller but the principle is the same. Lower temp lower efficiency.

    I appreciate the efficiency is probably better than it was 10 years ago and the overall quality improved but the problem in Ireland is getting quality installation as with everything here. Ireland is fully of dodgy trades people and this is a real issue no matter what you try to get done.

    And if the installer goes out of business you're screwed consumer protection isn't worth a damn thing and consumer protection can't make the installer fix your HP, they can say they have to etc but they can't male them, if you have serious trouble with the company who installed it you're likely looking a going the legal route and where will that get you ?

    High energy bills are usually , or so I was told due to the wrong Hp being installed for the job, either too large or too small.

    I was told retrofit can indeed work with radiators with the heliotherm ground water pump which can heat to 50+ deg C and if you can get away with lower temp the efficiency can even surpass the quoted cop of 7:1.

    Now my thinking about it is if I could get it installed and it consumes at least the same cost in electricity as oil which would be around 1200-1400 depending on oil costs I could live with this because the house would be warm 24x7 and I can add solar PV eventually.

    Of course the cheapest thing to do is add insulation in the long rum but we need to upgrade the heating, replace rads , plumbing etc , the boiler is ok. If it were to cost 20 K for hp I wouldn't touch it at that price I would wait until the costs drop significantly. I realise I would not save a lot compared to oil but I would like not to have to use oil even though I know a lot of my electricity comes from Gas some from wind etc at least the more wind and solar we add to the grid can make heating very clean.

    20 K for hp, give or take not a lot of saving per year to run and maybe 20 years life, that is a huge cost.


  • Registered Users, Registered Users 2 Posts: 2,830 ✭✭✭air


    Installation quality is far less of an issue for ASHPs as the units come as a mono block that only requires power plus flow and return pipes to be connected.
    Still plenty of scope for a poor overall system design though of course.

    There are cheap no name ASHP units sold on eBay UK that have s pretty solid reputation and are likely to perform reasonably close to the higher end units in reality for a fraction of the cost.

    Retrofit with radiators is always going to be a challenge economically as without UFH you've no storage buffer that you can charge up cheaply with night rate electricity.
    You could install a buffer tank instead but it won't have much thermal storage capacity in practice.

    The difference between the max output of your heat pump and the minimum flow temperature you require will be too small.
    You're going to be buying a majority of your electricity at peak rates.

    UFH with tightly spaced pipes can provide heat with output flow temps in the mid 20s whereas radiators are going to require high 30s to low 40s typically.

    I've read that a rule of thumb is that every degree of additional flow temperature costs you 1% in efficiency.

    As a result of this (and a few other factors) I think domestic hot water from a (primary space heating) heat pump is a fools errand.

    In a retrofit I'd run it through the boiler coil (on a stat when the tank is cooler than flow temps) but bring it up to final temp with an immersion or instant water heater.

    If going down the PV + HP route you want it facing due South at a slope of at least 50 degrees slope to optimise for winter production.
    You need a good site for this to be viable as shading is much more likely at low winter sun angles.
    Even with an optimal PV installation it's not going to be a huge help for the average retrofit type house with no storage and a relatively high heat demand.


  • Registered Users, Registered Users 2 Posts: 34,105 ✭✭✭✭listermint


    Insulation can be extremely pricey. Going through a bit of an all the rage thing last 4 years.

    If your house is anything other than a classic semi detached 2 story then it's money money money.

    My quoted were coming in around 30k plus for detached bungalow circa 3000 sq ft. And the standard that I wanted was questionable.

    Most fellas were not entertaining taking out Eve's and going to top of block also I wanted to go below ground around two block's. I wasn't happy with the quotes and wouldn't have been happy with the spec finish for that price.

    So did it all myself and got a plasterer to finish. Cost total 12k. All materials , plasterer and my labour. 200mm EPS system.

    Would I recommend it to everyone? No you have to be a prick for hard slog and be single minded to the completion destination. Very easy to want to not finish and get someone in. Was there over 20 k labour in what I did not a hope which is where the unhappiness in paying that comes from.


  • Registered Users, Registered Users 2 Posts: 2,830 ✭✭✭air


    Insulation is expensive to retrofit, it's all the labour as you say. The marginal cost of adding additional insulation in a new build is tiny in comparison though.
    Your project sounds excellent and it would be great if you could share photos and /or further details, in a dedicated thread perhaps.


  • Registered Users, Registered Users 2 Posts: 14,452 ✭✭✭✭ednwireland


    listermint wrote: »
    Insulation can be extremely pricey. Going through a bit of an all the rage thing last 4 years.

    If your house is anything other than a classic semi detached 2 story then it's money money money.

    try insulating a near 200 year old house with sea sand in the mortar :rolleyes:

    had our upstairs ripped out to the rafters last year filled with insulation then insulated board, it has made a huge difference think it cost 6k in the end.

    dont think external insulation on 2ft thick stone walls would do much :D

    replacing a patio door that you could see daylight through top and bottom made a huge difference as well as getting a window fitter to check all the windows were closing properly as well.


  • Registered Users, Registered Users 2 Posts: 34,105 ✭✭✭✭listermint


    try insulating a near 200 year old house with sea sand in the mortar :rolleyes:

    had our upstairs ripped out to the rafters last year filled with insulation then insulated board, it has made a huge difference think it cost 6k in the end.

    dont think external insulation on 2ft think stone walls would do much :D

    Sure the 2ft would keep ya warm :p


  • Registered Users, Registered Users 2 Posts: 24,654 ✭✭✭✭Alf Veedersane


    BryanF wrote: »
    How does the Embodied energy of a wood fueled boiler compare to a heat pump (factoring Irish poor design/BER and primary energy factor) has there been any peer reviewed studies?

    Other than inner city urban areas, is timber ‘timber’ nox & Sox, worse than Irish power stations burning a mix of gas/oil/peat for elec generation, some of which runs heat pumps?

    The issue with timber is the particulates as opposed to NOx or SOx. Solid fuel heating is the biggest source of particulates in Ireland and that creates a not insignificant air quality issue.


  • Posts: 21,179 ✭✭✭✭ [Deleted User]


    Yeah the country is a rip off, people out to ride as many people as they can for as much as they can.

    I've no problem if the hp doesn't save me big money if it's not mad expensive to install and doesn't give a lot of problem, once the hp is the correct output for the job then it doesn't matter if your house isn't extremely well insulated.

    As far as I'm aware it's better for the hp to be running more than cycling on and off like an oil or gas boiler.

    I would not like underground heating in our climate, it's too changeable. Could be 4 degrees C at 6 am one morning and 15 the next. Not a hope, it would drive me nuts.

    Once we get a fit then any exported energy in the Summer can be bought back to power the HP in winter, this is how the in-laws do this in Germany only they're feeding storage heaters and it works brilliantly.

    If we can use the groundwater HP it would be much better than a A2W.


  • Registered Users, Registered Users 2 Posts: 12,136 ✭✭✭✭KCross


    I would not like underground heating in our climate, it's too changeable. Could be 4 degrees C at 6 am one morning and 15 the next. Not a hope, it would drive me nuts.

    Can you explain your logic there because it makes no sense in relation to UFH.

    HP's and UFH have weather compensating controls that maintain your house at a constant temp regardless of outside temp.

    If it 4°C this morning and 10°C tomorrow morning your house will still be at 20°C (or whatever temp you decide). I think your impression is that the UFH is hot to touch like a rad... its not.... its running at less than body temp so not hot to touch.

    Explain your logic anyway as I think you've got the wrong end of the stick in relation to HP's and UFH.


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