Geothermal ESB costs for a year


Hi mudhut,
I have UFH with geothermal and wooden floors (Junckers). I think you may run into a problem even with old wood in Ireland as the damp summers (when the UFH is not on) cause the floors to swell, while the winters (with the UFH on) cause the floors to contract. Mad isn't it? You'd think the winters were the cause of damp! Anyway, I would worry for you that in the summer the old wood would bow as it expanded.

For the continuation of this thread, our full electricity bill for a 220 sq m. house with lots of glass came to €2000. I reckon about €1200 of that was for the heating/hot water.
 
Hi Yoganmahew. do you have a floating floor or are your boards glued directly to slab ? I have heard engineered floors are more suitable for UFH .. but I am set on natural.. One floor guy told me to just leave a qurarter inch or so between wall and floor boards to allow for movement.

here is a link to the floor guy I found on the web no affiliation !! [broken link removed]
 
Floating.

Beware - many guys will tell you many things. You won't see them again in a blue fit. Try and get a guy who has a land-line number who advertises in the yellow pages. No guarantee that they will be any good, but it does at least mean they may be there to complain to and they aren't just going to go and buy another ready-to-go phone.

The Junckers floor I have is solid beech. They also do wide (12.7cm) plank versions of some woods.

The agedwoods place is pricey, isn't it? About the same as Junckers excluding shipping.
 
Hello yoganmahew

There is nothing Cheap about them , I have looked around and found that all wide plank / manufacturers and suppliers are in the same price range , trees are not let mature to those widths anymore making wide planks an expensive item. guess it comes down to personal taste

MudHut
 
I know we're all on the same page, kindof.........but the OP said UFH and electric. To me, that's electric UFH.........although that would be nuts........

Anyhoo, regarding to UFH/or not UFH, I would say this: I have UFH for 10 years, and just completed a new build with UFH everywhere, so I've good experience of it from a long term perspective.

Some people like warm/hot houses - some like ones bordering on freezing. I like the former, and my SO even more so, and you couldn't give me rads for free - I had UFH downstairs and rads upstairs in my last house, and the rads are a pain. Big, stupid, inefficient.

I don't agree that the house responds too slowly, although it does respond slower than rads. There again it's supremely comfortable, and that's worth something to me.

Actually, carpet isn't so bad, but laminate isn't great. I have tiles nearly everywhere, and 15mm engineered floor in the master bed, and it's very good.

Did all the maths, and geo is just not at the races, price wise, so didn't bother. Did do solar + LPG though, and it definately works. Would not advise oil or solid fuel for UFH systems.
 
galwaytt said:
Did all the maths, and geo is just not at the races, price wise, so didn't bother. Did do solar + LPG though, and it definately works. Would not advise oil or solid fuel for UFH systems.
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Why not oil? Isn't the controllability of oil the same as LPG and the net energy cost lower?
 
DQuinn said:
HiPoppy,

here are the average daily running costs per month since I started recording the meter.

February€4.53
March€4.02
April€4.10
May€2.67
June€1.23
July€1.01
August€1.38

Total Daily Average€2.71
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DQuinn, Just looking at your figures (which are a great help, so thx!) Just a question in relation to the calculation of the 'Daily Average'. Did you take into account the different number of days per month? It looks like you totaled the daily average per month and devided it by 7 months?
If you calcualte the weighted average you are looking at a (slightly) lower daily running cost of €2.68
(I'll try to explain the calcualtion. Weighted average = (daily ave x days in that month) = Monthly total. Sum all monthly totals and devide by the sum of days for all months.)

So doing even better
 
Mudhut,

We have wide board engineered floors in our house. We glued them down and have had no problems. You said you wanted a natural board, the top 5-6mm is a natural wood its just the bottom part which is engineered. You get as much natural wood as a full solid board from the tounge and groove up, so you have as much wood to sand back over the years as a fully solid board.
 
Quasiff said:
Why not oil? Isn't the controllability of oil the same as LPG and the net energy cost lower?
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LPG boilers apparently are more efficient at lower temperatures which pairs them nicely with UFH.
 
LPG boilers apparently are more efficient at lower temperatures which pairs them nicely with UFH.
Click to expand...

My standard Firebird boiler sends out water between 60 C and 90 c. With the flow at 60c the water takes between 2 and 4 hours to return to the boiler at 60c and yet the temp of the screed is between 30 and 40 c owing to the manifold mixing valve. The manifold valve mixes according to the heating curve selected. I'm not sure that the LPG system would be less expensive given the fact that it is more expensive than oil.
 
I have full planning permission and hope to build a 3,000 sq ft dormer next year. I'm currently looking at building with Poroton block or else extra wide cavity standard block built house with bonded bead. Anyway I am considering UFH but have the following questions about UFH:

Is it inefficient as the floor must be kept heated during the night and day when nobody may be in the house? Would it not be more efficient to flick a switch and heat the house via radiators when required? What about all the eveings you decide to go out, weekends spent away, who needs heat in the house at night...

Do the controls 'know' when really cold weather is on the way and adjust accordingly? If a frosty night appears for example will the system know to turn up the temp that day in anticipation of the cold night?

For spring and autumn when the central heating is not required every day what happens when a cold evening appears? Won't it be too late to turn the underfloor heating on that evening or is it just left on all the time (inefficient?). Likewise in the middle of summer if there happens to be a cold evening? Perhaps a secondary system such as wood pellet stove would be the answer?

If solid fuel and oil is unsuitable for UFH then does that leave you with geothermal and LPG? I'm not convinced geothermal is viable (huge initial cost, potential lack of heat from ground, rising electric costs and the cost of replacing the equipment some day - probably just as it has paid for itself!!).

Anyway doing a bit of a devil's advocate on UFH... sounds really nice but just thinking of the practical considerations (cost!) and trying to figure the true cost of 'always on' UFH compared to conventional 'heat when needed' approach of radiators.

All comments welcome!!
 
Barney my dear man,

As we all know short trips in a vehicle in and out of town, from carpark to carpark getting the old prezzies the car uses up more petrol in the short period to start the car, drive a short distance and stop again. It's more efficient to heat the floor to a required temperature, rather than heat it when required, turn it off when not required and then fire it up again when you want the house heated.

Since this is in the Geothermal section, my heat pump has an outdoor temperature sensor that can tell what the weather is doing outside and accordingly works harder or easier depending on the requirements.
My pump works for 4 hours in the morning and heats enough hot water for the ufh, washing the body and the dishes. If you set the pump at a low enough temperature in the Autumn, Spring it'll just keep ticking over, and you'll always require hot water i'm sure. You wouldn't have turned off the heat this summer anyway, were getting better weather now than in June/July.

I think you should break done the cost of any Geothermal/UFH quote you'll get going on the size of your house in comparison to yours i'd say you'll pay €8,000 on the UFH piping alone, and thats with any system you'll go for. It seems to me your not giving any hope for UFH and Geothermal at all. Make sure if you do go for a Heat Pump you go with a experienced firm, to many people have been stung with this thats why Geo is getting the bad rap, if its not properly installed you may as well throw your greens into your big open fire.
 
ted said:
My standard Firebird boiler sends out water between 60 C and 90 c. ...........and yet the temp of the screed is between 30 and 40 c owing to the manifold mixing valve.
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That's exactly my point -you're heating the water 60-90, and you only need 30-40.

Why not just heat it 30-40, is my point - oil burners (and solid fuel) can't do that, but gas ones can, that's all I'm pointing out.

And, if LPG is more expensive than oil, on a per-litre basis -what does that matter, if you're using fewer litres??
 
JoeHooker said:
It's more efficient to heat the floor to a required temperature, rather than heat it when required, turn it off when not required and then fire it up again when you want the house heated.
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Thanks for the reply Joe. Perhaps I should have placed my comments in the UFH post rather than Geothermal. Apologies.

Anyway if going with UFH then obviously you keep the heat ticking over. As an extreme example however, if I am only in the house 2-3 days a week would it still be better to have UFH running 7 days a week rather than heat the house with radiators for 4-5 hours each of the 2-3 days as required? In other words is it not a lifestyle choice?

Like your analogy with the car, if I only use it when really needed then is that not better than keeping a super efficient one running the whole time? Tks, Barney
 

Surely the mixing manifold will make sure you only add enough energy whatever temperature the primary heat source is at? If so, then LPG is going to be more costly to run than oil, assuming SEI net energy costs are correct.
 

This doesn't make sense to me. The house is losing heat by conduction in proportion to the temperature difference between inside and outside. If you keep the house warmer when you aren't there, you lose more heat by conduction than if the house is colder.
 
With recent increases in oil prices, does this support the use of geothermal v traditional oil boliers? Surely electricity prices will soon rise with oil and thus increase the cost of the geothermal heating method?
 
For anyone who is interested, I have moved into a new house 3,400 sq.ft. since december. From my calculations all my heat and hot water requirements are costing circa. €25 per week and thats for constant hot water with a constant temp of 21 degrees in living areas and bathrooms and 18 degrees in the bedrooms. Given that the last month has been extremely cold I think that this is extremely economical when compared to any other heating system?
 
I built a new house in 2005 and put in an Avenir (french) geothermal system supplied by WHI (Warm Floor Irl), now based in Dungannon. I found them very professional and supplied me, with drawings for everything ) plumbing, electrical etc.
The system is working very well, and cheap to run (basic running cost is 30 night units at €.07 per unit. It depends on time of year and temp. if you need a top up during the day, maybe for a couple of hours( that would be at €.14 per unit.
I also put in a Pallazetti pellet stove in the living room, which is also interlinked by design by the same firm, for the reasons that it is useful for additional space heating, puts heat into the Domestic Hot Water, and it is nicer to look at than an empty grate.
A general rule for size of horizontal ground collector is 1.5 times the square footage of your house.
I hope the above is of some help to you.
 
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