Geothermal and UFH Vs Oil and Rads

selfbuiler

Hi, I just recived planing for my one off dream home. I`m unsure should I go for Geothermal and underfloor heating OR should I go for just and oil burner and Radiators. PLEASE HELP........

meercat

well done with your planning.
geothermal and ufch would be best but the installation costs are massive compared to a conventional system.you would have to compare both systems pricewise to see whats best for your pocket.

Outkast_IRE

why dont you want to do oil burner with the underfloor ? Is the house a massive square footage or somethin?

selfbuiler

Thanks for getting back to me, the house is about 4000 sq foot incl the farm office. Its just that some people say that the electricity bills with Geo+UFH are massive. Also I know of some cases where they have an oil burner and UFH and there not that happy. A plumber was telling me to go to town with the insulation, put in rads and maybe a stove or a small pellet burner to boost it...... Any thoughts

Outkast_IRE

Ok rule no 1 with underfloor heating is insulate the house as much as possible , really do the best you can in this area , and draftpoofing is essential , what you need to realise with underfloor is this

You are trying to create a constant ambient temprature that you find comfortable in the house , to do this you need room thermostats or area themostats .
To maintain this constant ambient temprature you want a really well insualted house otherwise this heat is quite literally being lost through the walls, ceilings etc and you will struggle to achieve what you want . The more insulation and more draft proof the easier it is to maintain temps .

Underfloor in regards to using it is totally differnt to rads , as i said you want to achieve a constant ambient temp which is comfortable its a totally differnt type of heat to rads you cant just turn it on when your feeling cold it will take ages for the house to heat then .
You need to set up timers correctly and have the system zoned to a few different areas and then use room stats in these areas to achieve this constant ambient temprature .

Underfloor is great if the house is properly insulated , the users of the system understand how it works , and the pipework is laid correctly and zoned correctly and thermostats function correctly.

People have poor opinions of underfloor sometimes cause
A. the amount of insulation even in new builds can be brutally bad
B. they expect the system to work the same as rads (it doesnt totally differnt type of heat)
C. They fail to understand you want to maintain this ambient temp an example is if open a window in a room with a rad and close the window again shortly afterward then the rad will heat the room relatively quickly , with underfloor the room will take much longer to heat . its all about maintaining the heat in the building .
If you maintain this heat it will cut costs dramatically because when the heat is kept the thermostat will close the zone valves accordingly .

If all these factors are done to the best of you ability , oil or geothermal will work fine for ya , however if it was me i would go for the oil myself and really talk to the architect about insulation draftproofing etc to minimise heat losses. Underfloor done right is lovely

hope you understand

also wouldnt touch off a pellet burner personally , a stove could be a nice addition and with the house properly insulated it would be worth your while.

JohnnieK

selfbuiler wrote: »

Thanks for getting back to me, the house is about 4000 sq foot incl the farm office. Its just that some people say that the electricity bills with Geo+UFH are massive. Also I know of some cases where they have an oil burner and UFH and there not that happy. A plumber was telling me to go to town with the insulation, put in rads and maybe a stove or a small pellet burner to boost it...... Any thoughts

It all depends on the COP of the unit. If you get a unit with a COP of 3.5 then it will be hard on the ESB bill but if you get one of 7 then it would be better. The COP is the rate of usage. for 1kW/Hr of electricity you would get 3.5kW/Hr of energy if you catch my drift.

I've no interest in them to be honest I am an oil and gas man myself. Why as the other poster has suggested go for an oil condensing boiler for the underfloor and hot water with a solar system on the hot water to. Your oil bills for the house would be very good indeed.

freddyuk

JohnnieK wrote: »

It all depends on the COP of the unit. If you get a unit with a COP of 3.5 then it will be hard on the ESB bill but if you get one of 7 then it would be better. The COP is the rate of usage. for 1kW/Hr of electricity you would get 3.5kW/Hr of energy if you catch my drift.

I've no interest in them to be honest I am an oil and gas man myself. Why as the other poster has suggested go for an oil condensing boiler for the underfloor and hot water with a solar system on the hot water to. Your oil bills for the house would be very good indeed.

I quite agree with the above except Geo thermal is a bit of a no no at the moment because it uses electricity which s the most expensive fuel.
Go for underfloor heating system as it costs very little to do on a new build. It is only plastic pipe laid over insulation in the screed. A few valves and controls do not add up to very much and it works great but as said you must zone the building and understand how to set it up effectively.
Put the pipes in anyway it will not be wasted money.
Same goes for geothermal. If you are not sure then lay the pipes and leave for connection in the future as an option. Plastic is relatively cheap and the land is probably torn up anyway?
Undefloor uses low temperature water so less heating and an Oil boiler would be fine providing it can run at lower temperatures.
Solar panels will heat your DHW in Summer and again are easy to install. You will regret not doing this while you have the chance.
I retrofitted underfloor in a section of my house and it is brilliant. DIY install.
I also fitted a log burner because this is very cheap to run and keeps the old part of the house toasty and a good one is really efficient.
Do some more research before you decide as i think you need some good advice.

twenty8

It appears to me that most of the comments so far are from people with Geo and UFH. I have both and would not change. House is approx 3,500 sq ft and the missus loves her heat as too do the kids. It would cost another mortgage to heat this place via oil burner. With the geo I have a very warm and cosy house. At what cost??

Well my yearly electricity bills are roughly €1,400 which I consider reasonable. Don't forget that that cost also includes all my other electricity uses - lights etc etc.

I thoroughly recommend it - but as an earlier poster said there is a larger upfront cost - and you will have to review your budget against that. Any questions - don't hesitate to ask.

freddyuk

twenty8 wrote: »

It appears to me that most of the comments so far are from people with Geo and UFH. I have both and would not change. House is approx 3,500 sq ft and the missus loves her heat as too do the kids. It would cost another mortgage to heat this place via oil burner. With the geo I have a very warm and cosy house. At what cost??

Well my yearly electricity bills are roughly €1,400 which I consider reasonable. Don't forget that that cost also includes all my other electricity uses - lights etc etc.

I thoroughly recommend it - but as an earlier poster said there is a larger upfront cost - and you will have to review your budget against that. Any questions - don't hesitate to ask.

Would you be able to give us a bit more detail on your system? ie. What type of house/bungalow- Detached or terraced.? Temperature setting for DH water.
How many zones.
Capital cost of the heat pump. Is that one heat pump or two?

I have just had the coldest winter ever and i did use more oil than normal however the total for the year will probably come in around euro 1,800 because it is an old boiler outside (heating a fair amount of garden right now) the loft needs reinsulating.The doors need draft proofing etc. so i reckon i can reduce that cost by 15% quite easily. My leccy is on top of course.
I will fit solar thermal panels and bolt them into the existing system quite easily and some solar PV to plug into the supply.
I reckon this will give me some serious savings as the technology is not difficult.
A good multifuel in the centre of the house keeps the core warm without other heating and uses very little fuel. Of course it needs tending though. Given the choice i would have U/F in all the house but i was not prepared to dig up the floors.

I am not sure about heat pumps or their longevity. I do know airconditioners in say Florida cost a lot in maintenance and these units must be similar in design/function.
I am really interested in heat pump performance as i have the space to fit the pipes but neighbours have been shocked by the leccy bills but then they have radiators so totally inappropriate system.

selfbuiler

twenty8 wrote: »

It appears to me that most of the comments so far are from people with Geo and UFH. I have both and would not change. House is approx 3,500 sq ft and the missus loves her heat as too do the kids. It would cost another mortgage to heat this place via oil burner. With the geo I have a very warm and cosy house. At what cost??

Well my yearly electricity bills are roughly €1,400 which I consider reasonable. Don't forget that that cost also includes all my other electricity uses - lights etc etc.

I thoroughly recommend it - but as an earlier poster said there is a larger upfront cost - and you will have to review your budget against that. Any questions - don't hesitate to ask.

"twenty8" Just a few quick questions?
1. which company suppiled your Geo-thermeal unit and UHF
2. What did it cost...(Aprox)
3. What insulation did you go with?
4. What is the COP of you unit..(see earlier comments)

Thanks again

twenty8

freddyuk wrote: »

Would you be able to give us a bit more detail on your system? ie. What type of house/bungalow- Detached or terraced.? Temperature setting for DH water.
How many zones.
Capital cost of the heat pump. Is that one heat pump or two?

I have just had the coldest winter ever and i did use more oil than normal however the total for the year will probably come in around euro 1,800 because it is an old boiler outside (heating a fair amount of garden right now) the loft needs reinsulating.The doors need draft proofing etc. so i reckon i can reduce that cost by 15% quite easily. My leccy is on top of course.
I will fit solar thermal panels and bolt them into the existing system quite easily and some solar PV to plug into the supply.
I reckon this will give me some serious savings as the technology is not difficult.
A good multifuel in the centre of the house keeps the core warm without other heating and uses very little fuel. Of course it needs tending though. Given the choice i would have U/F in all the house but i was not prepared to dig up the floors.

I am not sure about heat pumps or their longevity. I do know airconditioners in say Florida cost a lot in maintenance and these units must be similar in design/function.
I am really interested in heat pump performance as i have the space to fit the pipes but neighbours have been shocked by the leccy bills but then they have radiators so totally inappropriate system.

Don't have all the details that you need but here is what I have that you are looking for.

Detached house - 2 storey
water is set to 49c for general use. UFH varies depending on the external temp etc - eg today it is at 26c.
Zones - in every main room (5 downstairs and 4 upstairs - none in bathrooms or halls etc)
1 heat pump - 12kw - Nibe (link to exact model) http://www.nibeonline.com/pdf/031153-2.pdf
Can't remember cost of the pump. Was included in overall quote for the house. He did say that it would cost an extra 10k for the Geo + UFH option v oil burner and rads. (therefore cost would be the oil burner etc plus 10k)
Insulation - have a heck of a lot... panel board on all external walls and cavity filled with insulation board.

Hope this helps you.

Balmark

IMHO you've something else to be looking at

Insulate to the max (loads under the concrete floor and throw up insulated slabs inside the outside walls (aswell as cavity insulation) as was said above

however .. you've a GREAT opertunity to get your heating for zip
You said farm office, so I assume you've a bit of land ..

Throw up a windmill and put it straight back into the ESB grid, get $ off your elec.. the running cost of the geothermal/underfloor is only electric

I don't know anyone yet who's hooked back into the grid for electricity/windmills and I'm not sure what you can get from the ESB (credit, $ or what) .. but oil and gas will only go up and up and up pricewise, if you can balance your electricity with a windmill, you'll be paying sfa if anything at all

Geo/UFH is all about upfront cost and saving in the long run imho

FreddyUK mentioned below 'Geo thermal is a bit of a no no at the moment because it uses electricity which s the most expensive fuel' .. which imho isn't all that accurate, you're not doing a 1to1 electricity, from what I gather, you put in 1 part electricity (running pump + converter) to get 4-5 parts heat equivilant out ..

Running your heating on elec heating elements (heat bars) isn't the same as running a pump/convertor for the geo at all.. they're very very different consumption wise.. also, just a quickie, I've heard of a few people who got monster bills from geothermal and the aircondensing systems .. but it turned out in both cases that it was their setup, somehow, they had the units heating water from 0-50 or something but they'd set the thermestats on the backup emersions at 60, so the emersion was ALWAYS keeping the water hot, not the geo :P

If you know someone getting insane electricity bills, it'd be worth their time getting someone in to take a look at the system or get back onto the guys who installed it.. I just installed it, moving into the house in a month, looking forward to finding out what the costs will be for me

freddyuk

I mentioned that running a wet system off Geo would be a disaster as the running temperatures are way too high. The water comes off the ground loop at 10c on average although claims are made for higher temps of course. Then it has to be heated to 55c for DHW or just 25 - 30c for underfloor.
A 12 kw Heat pump with a COP of 3.5 -4 will use 4 kw to run the water up to temperature? I am asking because i don't know but if you are running 4 kw unit that is going to make your meter spin!
Other will know exactly how long it takes to get water to the correct temperature as there are formula for all that BUT i still reckon that to lay out £6-7000 for a Geo system and use 4kw for any length of time will never reach payback.
A system using Multifuel stoves, solar and oil backup (and very possibly wind but i doubt it ) in a well designed system will enable you to reach payback in your lifetime.
Solar has no moving parts so once bought and fitted it is working in varying degrees all the time. That includes thermal and pv. Now you can feed it back to the grid it will earn even if you are on holiday.
Just my angle of course.
As is say i am just an amateur so others will put me right.

meercat

agree with freddyuk and anyone else who said electricity costs to run these systems are high.i have connected a few systems,not installed by me and each client has been disappointed by the high running costs even on the nightsaver metering

twenty8

Balmark wrote: »

II just installed it, moving into the house in a month, looking forward to finding out what the costs will be for me

Be prepared for exceptionally high costs in the first few weeks. A lot of energy is spent on drying out the concrete screed and getting it up to the right temp. But don't worry - it settles down shortly after that.

JohnAC

selfbuiler wrote: »

Hi, I just recived planing for my one off dream home. I`m unsure should I go for Geothermal and underfloor heating OR should I go for just and oil burner and Radiators. PLEASE HELP........

The more you analyse various heating systems the more evident it becomes that Geothermal is by far the most superior of all the mainstream heating systems. In reality it actually does run at about 75% cheaper that oil. It provides you with a constant temp all year round without running to time clocks to reduce oil expenses etc.
There is a lot of daft misguided info out there, your esb bill will not be excessive with a quality heat pump. Of course the electricity is expensive for storage rads etc but heatpumps use electricity for the compressor and gets the majority of energy for your home from the ground. Avg annual bill(in my experience) for a 2800sqft house with an avg heat loss of about 50w/m2 would be about 900euros. http://www.anewera.ie/geothermalpayback.htm You'll get your return on investment in a few years and bear in mind once the system is switched on you have little or no input regard servicing etc. If your budget is tight you can run the system without stats until you wish to install them as the system with operate good enough temps at least with Nibe systems. In the meantime the systems will run fine.

I install oil and geothermal systems and can’t understand why people go the oil route but it seems once they make their mind up there’s no going back. The following should be taken into account with oil;
1) Very costly to run (if you pack in a fortune of insulation it would be good for any heating system!!! If insulation is high you’ll have a smaller thus cheaper heat pump.)
2) Oil is at an unrealistic price level.
3) You will have to install more expensive equipment at the manifolds to reduce the high temp coming from the oil to the under floor.
4) Unit servicing/maintenance costs
5) Unsightliness of system etc..
6) Systems is only running for a number of hours (as opposed to geo 24/7)

Anyone that I know with Oil/Under floor are under the impression that something is wrong with their system as they can’t understand why it’s so expensive to run.

I wouldn’t dis pellet systems-they have their applications too..

In summary there is absolutely NO comparison when it comes to doing the figures and not wasting your money and getting the fastest return on your investment I'd recommend you install geothermal with a tidy solid fuel stove (just for the natural fire effect but in reality you wouldn't need it). Forget about the rest (I can provide you with the figures to support all the above).....John

RavenII

selfbuiler wrote: »

Thanks for getting back to me, the house is about 4000 sq foot incl the farm office. Its just that some people say that the electricity bills with Geo+UFH are massive. Also I know of some cases where they have an oil burner and UFH and there not that happy. A plumber was telling me to go to town with the insulation, put in rads and maybe a stove or a small pellet burner to boost it...... Any thoughts

We're about the same size house and replaced the oil boiler with a Nibe 12kW heatpump. The house is 340m2 and a garage/playroom of 70m2. Now we have bigger ESB bills of course...€1240 extra last year and abou €1400 this year, but that's about a saving of almost 2K anually on what we were spending on oil (more again when oil was dearer)....always makes me laugh when we hear about the 'massive' ESB bill complaint! Unless you have free logs and heating is your hobby, I don't think there's a cheaper way to do it, but get you insulation and your air-tightness right

JohnnieK

With a very well insulated house and a properly zoned heating system and a condensing oil boiler you would nearly half your oil consumption, and the installation cost would be a lot less.

It's all down to insulation at the end of the day.

I completed a ground source heat pump course a couple of months ago and I'm still not convinced. Either was the lecturer that instrucded us ( which to me says a lot).

selfbuiler

Sorry lads I ran into some planning problems and the wife had a baby but its full steam ahead now....

So the following is what I`m thinking of going with.....
1.I`m going to go mad with the insulation, the airtightness etc(with in reason)
2. I`m putting in the Under floor (Uf) pipes in both floors when building it. Inculding wiring for the stats.
3.We are putting in a mulitfuel stove with heating vents from the flue heating the rooms upstairs and downstairs where the chimeny passes thru.
4. A wood pellet stove room heater in the kitchen/constovry. 14 kw one on a timer/room stat( I have done a good bit of research on it and the feed back is good.....
5. solar on the roof for the hot water
6. And finally a tradtional boiler with rads with 4 zones

After 3 to 4 years I will put in a Geo heat pump and a turbine on the farm.
and then i will use the UF pipes
Cost
Due to the size of the house I have to get either 2 geo pupms or 1 geo pump and and oil burner Cost 36000

The above plan is coming in at around 20000
So what ye think lads, I found your comments last time very helpful......
all the best selfbuilder
ps the baby is tedding

Carlow52

Good luck with the baby:)

Some ramblings:

1: do some research on the heat from the flues idea. There is a body of opinion out there which says that these vents cool the flue too much and you get a poor performance from the flue, increased condensation and shorter flue life due to acid.

2:
If I read you right, over the teething baby ,you will have an ope in the upstairs floor beside the chimney where it passes through the ceiling from the room below.
If so, noise will be an issue, as will smells and I would have smoke transmission concerns in case of a fire which the smoke alarm may not catch

3: the cost of UFH piping that wont be used for 3 or 4 years is not to be sniffed at.
Instead of Geo, consider MHRV

4: for an exposed site, (farm) consider external air vent directly to the wp stove from both sides of the house to avoid pressure loss/ backdraught issues.

As a matter of interest how often will u need to refuel the wp stove?
Keep well

johnb25

selfbuiler wrote: »

Sorry lads I ran into some planning problems and the wife had a baby but its full steam ahead now....

So the following is what I`m thinking of going with.....
1.I`m going to go mad with the insulation, the airtightness etc(with in reason)
2. I`m putting in the Under floor (Uf) pipes in both floors when building it. Inculding wiring for the stats.
3.We are putting in a mulitfuel stove with heating vents from the flue heating the rooms upstairs and downstairs where the chimeny passes thru.
4. A wood pellet stove room heater in the kitchen/constovry. 14 kw one on a timer/room stat( I have done a good bit of research on it and the feed back is good.....
5. solar on the roof for the hot water
6. And finally a tradtional boiler with rads with 4 zones

After 3 to 4 years I will put in a Geo heat pump and a turbine on the farm.
and then i will use the UF pipes
Cost
Due to the size of the house I have to get either 2 geo pupms or 1 geo pump and and oil burner Cost 36000

The above plan is coming in at around 20000
So what ye think lads, I found your comments last time very helpful......
all the best selfbuilder
ps the baby is tedding

We have Geo & UFH, 2.5k sq ft single storey detached house.
I find it expensive, as has to cut in too much during peak rate to maintain temperature. Our insulation is not exceptional, which is part of the problem.

Definitely go heavy with the insulation, any system will benefit from it.
If putting in the UFH pipes and conventional boiler, why not run UFH from the boiler? With good insulation it should be good and economical.
I'm no expert, but if you are designing the house with insulation etc to UFH spec, why not do it from day one?
One thing I like about UFH, apart from the heat, is not having any radiators.

Solar for hot water definitely a good idea.

Are you putting in Heat Recovery Ventilation?

One final thing, get tradesmen who have experience in UFH etc, and who understand the difference between conventional and UFH house requirements.

Best of luck with it....I wish I was building now rather that four years ago..

Jrochey

Hi Guys, quick question starting a self build next year just wondering about installing geothermal in conjunction with a log burning stove. Would the stove not heat up the water in a buffer tank therefore reducing the need for the heat pump to kick in as often would it reduce bills also is there still grants out for installing geo heat pumps what do ye think.

freddyuk

If you are self building then i would forget grants as you will end up paying a contractor to charge you over the odds for a system you can install yourself and for a lot less money. If you cannot self install then you may as well go for the grant option.
There is no reward for fitting and running these systems in Ireland and unlikely that will change.
I would have solar thermal into a buffer tank plus WBS into same tank (twin coil) If you have room in the attic and can put the buffer tank above the WBS then this should be ideal. I assume your are not going pressurised?

If you are on mains water then you could fit a plate exchanger for the dhw from the buffer tank. (no issues with a pressurised system then)
You could have a geo system plugged into this also but so far we are not using any electricity.
If you have a decent WBS with back boiler in the correct room in the house it will do a great job of keeping the "core" nice and warm.
I would then have a traditional oil boiler that could also burn biofuel.
Underfloor all round. That will cover most situations with the boiler only kicking in when needed. Modern boilers do not like running at low temperatures. An old fashioned oil burner will not be used enough to become inefficient. Nothing to go wrong. Can be fixed easily if it ever did.
I am not a fan of geo thermal until i see evidence it is efficient and cost effective. However putting the pipework in is a good idea.
I would suggest you plan your house around an effective multi fuel stove in the middle of the house. They are brilliant.
With solar and WBS into a buffer tank if it is big enough you could run the underfloor on a good day but it would need to be properly sized and controlled.
If you had some PV panels then you would be able to run it all off the sun.:)

RavenII

Jrochey wrote: »

Hi Guys, quick question starting a self build next year just wondering about installing geothermal in conjunction with a log burning stove. Would the stove not heat up the water in a buffer tank therefore reducing the need for the heat pump to kick in as often would it reduce bills also is there still grants out for installing geo heat pumps what do ye think.

You will heat your house and HW very cheaply from the heat-pump- they run at around 1/3 of the cost of oil (SEAI's latest energy figures give oil at 10c / kW - the heatpump costs about 3.5c kW Hr)...it's not worth messing about with buffer tanks etc.

Use a heatpump with the HW built-in and pressurised....the annual hot water cost is only €150 - €175. (about 5000 kWhrs year for your average Joe)

Its financially not worth connecting a stove to the hot water therefore and you drag the plumbing system back to the stone-age!

Just use a straight wood burning stove for atmosphere etc ...the heating system will interact in any case as the stats / heat load required will be picked up by the heatpump.

Jrochey

Hi guys, thanks for the info. Just wondering what the cost of installing geo would be now given the current climate has it come down at all. Friends of mine have a solar rads and back boiler to heat the house. Lots of people were saying the solar panels are not worth the pay back given they only work are the best during the summer months. Very confused by the whole thing is the geo just a fad that's out. Would it be a better idea to install the underfloor and have it so i could put a heat pump to it later on. Putting 4inches in the cavity surely given the improvements in insulation and windows the heat lost would not be that major. Plans are for a 2960 sq ft house any suggestions. Thanks

freddyuk

If anyone says that Heat pumps are really cheap to run simply ask them to provide figures to back it up. Not the SEAI who are there to promote it but someone who actually uses the system and has electricity bills to demonstrate the claim.
Anyone???

Also start with insulation as the cheapest option and of course draftproofing.

Include all plastic piping you may need as you cannot do it later and for the cost it is a wise investment in my opinion.

Solar works all year round if it is correctly sized and installed. The sun does not stop shining in the winter. It hardly ever shines in the Summer.
You will get hot water from it though. If you payback period is too long you are probably not getting a sensible price from your supplier/installer. It is a DIY job.

Geothermal supplies water from a source at a fixed temperature all year round give or take a couple of degrees. You just have to heat it up to 45 - 55c with electricity.

Your choice.

RavenII

Yep, I think my heat pump is really cheap to run, and I do have the figures to back it up ( and if you're near Enniskerry Wicklow, you can look).

There's cost monitoring equipment (individually on the HP and also the overall house)which shows that the 350 Sq. M (built 1971 - insulation could be better!) house cost €1620 for all heating and hot water (including the two heating and also collector fluid pumps)....for the whole year. That's 21/22 deg C 24/7 and 400L of hot water, which is re-circulated (a bit wasteful) given the house size. My Mrs is a devil for heat too...

The previous year it was €1460.00, but we had a tough winter earlier this year. The year before was €1250 odd, and the slight increase in ESB the difference I guess.

I just checked SEAI's website, and Fuel Cost Comparison tables...this is a 'no brainer'. Oil is 10cent + per kW hour burnt at 80% efficiency.

If you are in a newish house at say 300sQ M you will use around 30,000 kW Hours per year - so the cost on oil is 30,000 x 10c = €3000.

You could fit solar panels and save 3000kW Hours per year -€300.
You could also use a condensing oil boiler and maybe get down to 9c kWhr but that's still €2430...

Wood pellets are around 6c, so 30000 x 6 = €1800, pretty high installation cost though + maintenance & deliveries....but if heating is your hobby...

The average cost of electricity is .14c (60% day / 40% Night) and any half decent heatpump will return 4 units of heat for every 1 unit input, so just 3.5 cent per Kilowatt Hr and those 30,000 Kw hours mentioned above come to €1050.00

Looking at it another way my house therefore uses about 45,000 kW Hrs..that's €4500 accoring to SEAI and €4500 less €1620 used on the heat pump, so €2880.00 saved this year...that's why I'm not pricking around with pellets, buffer tanks, stoves etc etc

robd

Interesting debate.

When is a 4000 sqft house ever going to be cheap to heat though?

That's about 4 average size houses in one there.

Underfloor heating means you're going to be permanently heating the whole thing. You can zone it but unless you're permanently going to shut off parts you're not using you'll be heating it 24x7. That's the way underfloor heating works.

Oil, Gas, Geothermal, it doesn't matter. It'll be a dear house to heat relatively speaking. That's the price of your dream home though. Make sure to install a big oil tank if that's what you're going for. 1000l is standard for a standard house to scale accordingly.

RavenII

Jrochey wrote: »

Hi guys, thanks for the info. Just wondering what the cost of installing geo would be now given the current climate has it come down at all. Friends of mine have a solar rads and back boiler to heat the house. Lots of people were saying the solar panels are not worth the pay back given they only work are the best during the summer months. Very confused by the whole thing is the geo just a fad that's out. Would it be a better idea to install the underfloor and have it so i could put a heat pump to it later on. Putting 4inches in the cavity surely given the improvements in insulation and windows the heat lost would not be that major. Plans are for a 2960 sq ft house any suggestions. Thanks

Use a heatpump with the HW cylinder already built in. Put it in your utility room , not way off in the shed or garage, and what you need to figure out is the difference in cost over oil/solar which will be feck all, but maybe €2000 more. Your money will be saved in only two years.

RavenII

robd wrote: »

Interesting debate.

When is a 4000 sqft house ever going to be cheap to heat though?

That's about 4 average size houses in one there.

Underfloor heating means you're going to be permanently heating the whole thing. You can zone it but unless you're permanently going to shut off parts you're not using you'll be heating it 24x7. That's the way underfloor heating works.

Oil, Gas, Geothermal, it doesn't matter. It'll be a dear house to heat relatively speaking. That's the price of your dream home though. Make sure to install a big oil tank if that's what you're going for. 1000l is standard for a standard house to scale accordingly.

Depends on what the floor heating is in...ours is just at the back of the wooden floors in only 20mm screed and in alluminium plates elsewhere...it heats up almost as quick as rads...I just leave it on because we're 'having our cake and eating it'...at €1600 a year for the heatpump; my sister spends more on gas in her 3-bed semi in Foxrock!

Jrochey

Thanks again great responses from everyone. Just wondering the guys who did install the geo is there any changes they would make if they were going back again. Also just wondering would it be a good idea to heat downstairs with a heat pump and maybe the upstairs with an alternative heat source or is it just better to heat the whole thing with the geo. Or is it a waste of time. I'm going to go with concrete floors upstairs still wondering about underfloor upstairs tho not sure bout it any ideas from anyone. All the people who have the geo have said its great loads of hot water etc and all u have to do is put in loads of insulation. I know that no system is bombproof but starting out i'd like to cover all the bases. Thanks lads great advice just trying to decide hard to pinpoint would it be better just to insulate the beejaysus out of the house or is that going overbord.

nophd08

Jrochey wrote: »

Thanks again great responses from everyone. Just wondering the guys who did install the geo is there any changes they would make if they were going back again. Also just wondering would it be a good idea to heat downstairs with a heat pump and maybe the upstairs with an alternative heat source or is it just better to heat the whole thing with the geo. Or is it a waste of time. I'm going to go with concrete floors upstairs still wondering about underfloor upstairs tho not sure bout it any ideas from anyone. All the people who have the geo have said its great loads of hot water etc and all u have to do is put in loads of insulation. I know that no system is bombproof but starting out i'd like to cover all the bases. Thanks lads great advice just trying to decide hard to pinpoint would it be better just to insulate the beejaysus out of the house or is that going overbord.

A lot of very good information from all other posts and the one thing that is common in all of them is... INSULATION. When your house is properly insulated then it wont be expensive to heat.
I know of one 2800sq ft house built 10yrs ago and he spent over 8k punts on the best insulation available at that time. UFH installed on both levels and a few rads on 3rd level attic type room. About 1200litres of oil per year give or take to heat house and all DHW.
I think laying all pipes for UFH and Geothermal is the way to go.

freddyuk

I am almost convinced. Can I ask capital cost for the HP ? How much pipe was laid and how? Deep bore or slinky. Size?

My concern is always that you have one way of heating water. Any break in supply or equipment failure you can't even get a decent shower and it will happen on a Friday night Bank holiday.
Also we do not control the supply so it may rise especially as it is government controlled.
No one controls the solar.... and never will. Always free once paid for.

RavenII

freddyuk wrote: »

I am almost convinced. Can I ask capital cost for the HP ? How much pipe was laid and how? Deep bore or slinky. Size?

My concern is always that you have one way of heating water. Any break in supply or equipment failure you can't even get a decent shower and it will happen on a Friday night Bank holiday.
Also we do not control the supply so it may rise especially as it is government controlled.
No one controls the solar.... and never will. Always free once paid for.

Wrong there...the heatpump heats the water (it runs hotter for a short period to do this on priority) but there's immersions in the cylinder (unused) as backup and there's also an electric in-line immersion in the Nibe heatpump, also unused...so we have three ways of heating water...as I said before I spend so little of the total heating hot water (and I like solar) it's not worth my while spending a few grand on panels to reduce the €175 - 200 I spend on HW

The heatpump itself was about €6500+ we used a 150M borehole which cost about €4000 to do. Also there's about another 100M of pipe from the energy well to the house which saved us from having to do a deeper or second bore. The plumber got about €2000...We got a grant of €6500 from SEAI, which has been cut down to €3500 now and is only for existing houses. I think they take the view that new building regs make either solar or a HP mandatory so they don't need to support it.

RavenII

Jrochey wrote: »

Thanks again great responses from everyone. Just wondering the guys who did install the geo is there any changes they would make if they were going back again. Also just wondering would it be a good idea to heat downstairs with a heat pump and maybe the upstairs with an alternative heat source or is it just better to heat the whole thing with the geo. Or is it a waste of time. I'm going to go with concrete floors upstairs still wondering about underfloor upstairs tho not sure bout it any ideas from anyone. All the people who have the geo have said its great loads of hot water etc and all u have to do is put in loads of insulation. I know that no system is bombproof but starting out i'd like to cover all the bases. Thanks lads great advice just trying to decide hard to pinpoint would it be better just to insulate the beejaysus out of the house or is that going overbord.

Just use the geothermal HP for either floor heating or rads - I have both at home and the Nibe heatpump controls both systems linked to the weather which is good for comfort and savings.

If you're doing a concrete upper floor just put the UFH pipes into the screed attached to the steel mesh. (probably cheaper than rads) There's no insulation used (its an internal leaf in the house) and no additional structural expense, but another bonus is that you can getthe heatpump to run a little harder on the night rate and store the cheap energy in that slab.

shummy38

selfbuiler wrote: »

Hi, I just recived planing for my one off dream home. I`m unsure should I go for Geothermal and underfloor heating OR should I go for just and oil burner and Radiators. PLEASE HELP........

You can also go for underfloor heating with Oil. However the best option is to go with Geothermal and UFH. Cost is the issue here, with no grants available for new build your cost will be an additgional 5-6K over the oil/rads alternative . For a 3000 sq ft house you should save the best part of 2000 Euros per year with a heat pump.

I would suggest you go for one of the models that includes a hot water tank built into the heat pump

For choices I find Polytherm heating systems very helpful www.polytherm.ie or talk to Peter Mulvihill in their renewable energy sister company www.origen.ie 01-4191990 they are all in the same office and they sell rads and boilers too so they have no axe to grind either way.
Best of luck.

RavenII

Back-pedal to post no. 27 I left yesterday hope its a help...PM me if you want the installer etc. The heatpump is a 12kW Nibe 1145 model from www.unipipe.ie

shummy38

selfbuiler wrote: »

Hi, I just recived planing for my one off dream home. I`m unsure should I go for Geothermal and underfloor heating OR should I go for just and oil burner and Radiators. PLEASE HELP........

Thanks for that.

Im new to Boards so just getting the hang of things.

freddyuk

RavenII wrote: »

Depends on what the floor heating is in...ours is just at the back of the wooden floors in only 20mm screed and in alluminium plates elsewhere...it heats up almost as quick as rads...I just leave it on because we're 'having our cake and eating it'...at €1600 a year for the heatpump; my sister spends more on gas in her 3-bed semi in Foxrock!

What is under the 20mm screed? The whole idea of underfloor is to heat up the screed which is 75mm thick with 200mm of insulation underneath so it acts as a heat emitter. Once it is up to temperature it will maintain that heat for a long time in a well insulated draft free room. Mine will drop maybe 2-3 c overnight without any additional heating when it is several degrees colder outside. (Tiled flooring)
If you have 20 mm screed then your pipes are touching the timber floor as the o/s diameter of 15mm pipes is 18mm or thereabouts. This is why you need the heating on all the time because it will cool down very quickly if your pipes are not in 50 - 75mm of screed depth.
Thinking this through i guess you have thick timber flooring? The screed - if laid on 200mm of insulation would not be stable enough without a heavy flooring however you are then using the timber as your heat emitter?

RavenII

freddyuk wrote: »

What is under the 20mm screed? The whole idea of underfloor is to heat up the screed which is 75mm thick with 200mm of insulation underneath so it acts as a heat emitter. Once it is up to temperature it will maintain that heat for a long time in a well insulated draft free room. Mine will drop maybe 2-3 c overnight without any additional heating when it is several degrees colder outside. (Tiled flooring)
If you have 20 mm screed then your pipes are touching the timber floor as the o/s diameter of 15mm pipes is 18mm or thereabouts. This is why you need the heating on all the time because it will cool down very quickly if your pipes are not in 50 - 75mm of screed depth.
Thinking this through i guess you have thick timber flooring? The screed - if laid on 200mm of insulation would not be stable enough without a heavy flooring however you are then using the timber as your heat emitter?

The 20/25mm screed around my pipes is non-structural - its sitting on insulation boards between the joists. The floors are of course nailed to the joist. The Alluminium plates carry out the exact same function...the response time is quicker, but the really nice thing is that our heatpump is linked to the weather, so the floors change temperature with demand rather than most UFH systems which are set for the worst day at 45deg and then rely solely on thermostats for control which is a bit rough. When its say 7 outside the UFH water is around 31 deg...if its -1 out it climbs to about 39, so the heatpump always gives a very high return (C.O.P.).

I do the opposite in the rear of house, there's UFH in 150mm concrete - that's about a 1/3 of the total floor area. I stick an extra couple of degrees into that on the off peak rate and it acts as a flywheel effect to the entire system.

franb7111

"any half decent heatpump will return 4 units of heat for every 1 unit input,"

Hi all,
I will be starting a new build and looking at heating methods. However i have heard/ seen the above statement and was wondering if some one could explain it. Surely if you put in 1 unit (of energy ?) and get out 4 units this would solve the worlds energy problems? As far as i remember the law of conservation of energy states that " energy can neither be created nor destroyed but changed from one form to another " (except possibly in the case of nuclear fusion/ fission). I am not trying to be a smart A$$, Is this taking into account the total input of electricity over the entire year, (i assume that in the summer v little electricty is used) v the total heat output. Also If this is so wouldn't a geothermal system be far better than an airpump system as the temp difference in the winter between the air temp and several meters under the earth would be quite large (>10oC)

Plombier

Keeping the explaination very simple, in a heatpump you have a working gas, lets call it a heat transfer medium which, when compressed its temperature rises, so very simplified you supply 1 KW electricity(for compression) and get one KW heat from the heat transfer medium (1 KW in 1 KW out obeys the law), next the heat transfer medium is expanded back to normal pressure where it obviously drops in temperature because heat was extracted at the compression stage, next with an air source heat pump the fans blow vast amounts of air across the heat transfer medium which raises its temperature (this is the free bit but still obeys the law) and the cycle continues giving approx 3KW heat for 1KW electricity.

franb7111

Thanks Plombier, I just left there and visited a fw sites and i understand now, all the heat pump is doing is moving energy from one place the (out side) to another (the inside). However as the temp drops in the winter the free heat from the outside gets less and less so would you be better having an alternative heat source for UFH such as a wood burner or something. Also is geothermal not a much better option than a Air source pump or is the cost of geothermal usually cost prohibitive. I am building a 300sqm house to nearly passive standards and will be installing a HRV. The site is on a south facing aspect, so i probably won't need much heating from may to oct. (there is a 100 year old cottage on the site at the moment that we are in, its a bit of a wind tunnel but afgain we didn't need heating from may to oct) So i am wondering if one would still get the same benefit from a (COP 0f 3 to 4) from a heat pump is the heat output was measured over the colder months and not over 12 months

RavenII

Hi FranB, I see Plombier has explained the difference between power and energy!.... if you're building a super air-tight passive type house you should just look at using a smaller heat-pump...maybe an 8kW output unit instead of the 12kW one I have... in the coldest weather, a ground source heatpump is still cheaper than anything else at the moment and likely to remain that way. From the manual on ours if we have 7deg coming in from the collector in the garden and 35deg in our floor heating we get 5.7 units heat from each kW to run it.

An air to water HP will still work at -5 but its output is reduced on those occasional nights; thats why you always use some sort of 'back-up' with them,regardless of manufacturer or type. Also mind you don't over-ventilate the house with the HRV - another option too is to take the waste air into the heat-pump's collector fluid which is very clever.

weston1

trying to research all the heating systems out there and finding it hard to nail down the right one. firstly my insulation will be priority 1. 4000sq ft house, still unsure with the geothermal, and only cause i just feel i dont know enough. i was leaning towards that with ufh. now came across another system, turboburn. its a furnace that burns timber, waste oils, kerosene, whatever you have. it heats a large tank of water within the furnace rapidly and then the water sits there until needed, i assume the stats tell it when that is so. now you have to feed the furnace as required but this may be only once/twice daily in winter, every 3 to 4 days in the summer. just wondering has anyone heard anything about them. the salesman swears by it, as you would expect, but he sells the idea well and has good knowledge of heating. he runs a hostel on this and loves it. he has access to timber and used oils. he also told me he has a windmill up and it was the greastest waste of money ever. the unit is a copy of what is used in alaska. here's a link. i am intrigued by it but........ http://turboburn.co.uk/

RavenII

You will heat your house and HW very cheaply from the heat-pump- they run at around 1/3 of the cost of oil (SEAI's latest energy figures give oil at 10c / kW - the heatpump costs about 3.5c kW Hr)...it's not worth messing about with buffer tanks etc.

Above copied from my earlier post ...If you have a well insulated 4000sq. ft. house use a 12kW heatpump (I have a 12kW Nibe 1145 Geothermal heatpump in a slightly smaller house but it's not so well insulated) - It'll only cost about €1200 to €1500 for all heating and HW annually, and that's just a little machine like a fridge in your utility room which runs automatically...the other thing looks like it will be more expensive, has to have a boiler house... however if you like stoking boilers three times a day and heating is your hobby...!

Chipboard

I knew nothing about geothermal heatpumps or ufh until around 24 hrs ago and probably don't know alot more now, so maybe some of you my have some comments on the following;

I'm considering the purchase of a house which is 1,900 sq ft in area, a detached bungalow on its own large (exposed) site. I'm told the house is A rated but will be getting my own BER done just in case the first was fiddled. Two of the four bedrooms and all the living space have the sun all day (loads of windows).

The house has a Fighter 1220 system and under floor heating. I was a bit afraid after seeing a few posts on boards.ie complaining of high ESB bills so I bought an Owl energy monitor today and hooked it up to the fuseboard in the house (I have access even though I haven't even placed a bid yet).

I know nothing about how these things operate but it seems to have three distinct cycles so I monitored the power consumption and length of each and it was as follows;

Cycle 1 0.460 kw/hr 16 minutes
Cycle 2 4.380 kw/hr 3 minutes
Cycle 3 0.203 kw/hr 2 minutes

The only other power in use was a 200 watt bulb (no idea why he has 200 watt bulbs in several of the rooms) so the above is net of that.

I calculated from the above that it runs on each cycle for the following percentage of the day;

Cycle 1 76%
Cycle 2 14%
Cycle 3 10%

I used this to calculate that it will probably consume the following power;

Cycle 1 76% of 24 hrs 18.2 hrs @ 0.460 kw/hr = 8.37 kw
Cycle 2 14% of 24 hrs 3.4 hrs @ 4.380 kw/hr = 14.9 kw
Cycle 3 10% of 24 hrs 2.4 hrs @ 0.203 kw/hr = 0.49 kw

Total power consumption over 24 hours = 23.8 kw

23.8 kw X 14.1c per kw = €3.36 + vat = €3.81 per day

As it was around -2 degrees all day today this wouldn't seem an excessive cost to have the entire house heated and hot water.

Obviously it will be far cheaper for most of the year. Also, I'm fairly sure that tweaking the settings will bring efficiencies as the current settings were input by the auctioneer a couple of days ago and he knows even less than me about the system. I reckon I could turn down the heat a degree or two and still be comfortable.

I've left the energy monitor connected and will go back tomorrow to check the consumption over the 24 hours. The fact that the house isn't occupied will probably have an effect but I don't think it would affect it too much as the Fighter 1220 manual said something about appliances giving off heat.

Is the above too simplistic or just plain wrong?

freddyuk

Funnily enough i just received my free energy monitor from EON in the UK which i hooked up to my supply in Ireland last week. Change the currency and reset the rate and it was monitoring our usage which does not include any hot water or heating (except the C/H pump) as I have split U/F and radiators run off an oil boiler.
It had us mesmerized all week.
It averagely ran at 400 - 800 kwh daytime and 300-400 night time unless we used the oven or put the kettle on. I saw it peak at about 5.5 kw when both ovens were on. Microwave also pushed it over the 1 kw as they run at 700 - 800 kw however that is all very temporary. We have a gas hob. The mystery 1kw output during the night was traced to my well pump heater! Other large items include freezer and large fridge / freezer. Electrics on standby and computers are really irrelevant in the overall scheme of things. So I reckon my average was around 10-12kw per day which tallies with my recent Airtricity bills.
As i am fitting solar PV and DHW and possibly an Air Heat pump i am getting the before and after readings. It can be logged into the computer and charts set up to monitor the readings but sadly not into a MAC.

So to compare your readings for hot water and heating you can reckon the above numbers can be added as "other" non heating power. Not sure if hot water is included in your readings but the KWH number is getting scary.
We have 2100 sq ft. bungalow. Definitely not 'A' rated so we will have issues with insulation.
(I can confirm those instant one cup kettles use more power to make a cup of tea than a normal electric kettle.)

Maybe this will assist you.

Has not meant my wife has any clearer idea about zoning unfortunately.:D

Chipboard

Currently use 12KW per day so I expect to use nearly that much in the new house however I'm not factoring that in to my sums as I am only trying to guage the incremental cost of using geothermal and under floor instead of oil - I'll have the 12 KW 'other electrical costs' regardless of what house I am in.

If I use €4 on heating (for round figures) on the coldest day of the year and €0 on the warmest and average it out at €2 I would end up with a total annual bill of €730 for heating which would be fine as we currently use around 2.5 X 1000 litres X .55c which equates to almost €1400 per year on oil. They're are probably more cold days than warm in Ireland so will call it €1,000.

Even if it was the same cost it would be worth it as the quality of the heat is fantastic. The house we're in now, most of the time you feel a bit cold and you get the odd feeling of warmth when you are close to a rad but in the one with geothermal you can't feel the heat it just feels really comfortable. I'd say it will make it alot easier to get out of bed in the morning.

freddyuk

U/F is much better heat as you have noticed. It needs handling differently.
Let us know what the readings are today so we can make a better judgement.

Also getting oil for 55c is a bargain!! Where from?

RavenII

(FreddyUK) Meter reading 'scary'???? ....heating your house and running your lights, fridge, freezer etc etc for €3.84...I fail to see the scary bit there!

I don't understand the 'three cycles' bit?...the heatpump just does water heating (higher temperature & slightly higher power consumption when it's doing that job) and then the floor heating or rads at a lower temp.

Latest figures from SEAI: -
Oil Burnt at 80% efficiency 10.37 cent per kW - The heatpump averages (night/day rate) about 3 to 3.5 c per kW delivered.