Am hopefully buying a gaff.
My architect friend surveyed the 3 bed semi for me, and was concerned that the oil tank was on a dodgy plinth about 3ft from the back door.
He spoke with great enthusiasm about geo thermal heating. This seemed to involve drilling to the centre of the earth and heating your house with magma or something. I confess that my eyes glazed over when he mentioned the price tag of 13 grand. For that kind of money, i’ll just wear two jumpers. Another mate, who’s an engineer, reckons you’d have to look at next weeks forecast and turn on your geo thermal at least two days in advance of the cold snap in order to heat the house, and that the electricity cost with the pump would make your eyes water.
However, seeing as how the oil tank looks like an accident waiting to happen… have any of you converted from oil to gas or anything more exotic? Are you glad/sorry that you did? Did you have to sell a kidney to do it?
Thanks in advance for the knowledge.
Am hopefully buying a gaff.
Energy from the Earth’s core comes out at about 1W/m^2 on the surface. Ignoring efficiency, let’s say you managed a 100m^2 installation, so that’s 100W. Do you think you could heat your house with a 100W lightbulb?
Personally I’d consider solar (about 1000W/m^2), but the technology is still moving very fast so I’m planning on leaving it about a decade and see the state of play then.
I’m planning on going oil->gas on my new place, architect hasn’t raised any objections. Make sure there’s gas on the road, and don’t forget the SEAI grants for boiler replacement.
that Oil tank setup is fairly common - if the tank is in good condition I wouldn’t sweat it
the geothermal tends to have a buffer tank - at least the more common kind (not the one your engineer is pimping) does - though with a small garden it’s not feasible AFAIK - (Ground Source - doesn’t go that deep actually - basically a fridge in reverse)
seai.ie/Renewables/Geotherma … eat_Pumps/
my BiL has one -
there’s a lot more info on boards.ie
Actually, it’s less than a tenth of that on average, and it’s lower on land than on the seabed. It doesn’t matter, though, because the term “geothermal”, though common, is a complete misnomer for this type of system. It’s a ground-coupled heat pump – as the poster above says, a fridge in reverse. It’s supposed to yield “four units of heat per unit of electricity” from the bumpff I read when I was briefly considering installing one. Briefly is the operative word, since the payback time looked like longer than the lifetimes of the children I don’t have.
It produces relatively low temperature water which is why it’s a good match for underfloor heating (some sort of additional booster circuit can bring it up to immersion tank-type temps). I did opt for underfloor heating, and yes, it can take 24+ hours to come up to temperature from cold, although once you get used to the idea that you have to run it all the time, it’s a very comfortable type of heat. Can be a pain in spring and autumn when you might have lots of passive daytime heat and sudden temperature falls in the evening … in my experience it can’t adjust much better than one degree per hour. Still, I like it. However, it’s not a sensible option for a retrofit, only for new builds.
There’s the horizontal type and there is the vertical bore hole type.As noted, they absorb the heat in the ground and transfer it to the house - thing is with heat pumps they are most efficient during the summer when you least need them and least efficient when you do need them. If it’s a bore hole type I guess that won’t matter to much. If it’s efficiency you are going for, remember, by the time electricity is produced in a central power station and it gets to your house, you are looking at 25-30% efficient, then the condenser system has an efficiency of 4-5:1 so it brings it back to 100% (at the right conditions). Whereas a new gas boiler will create the heat at source, provide approx 96% efficiency.
The GSHP usually need a back up/supplementary, so you will have an electric element (sometime oil or gas) assisted.
One of the big issues with them is also noise, be careful where you position the condenser, I’m guessing because the oil tank is so close that the back garden might be small.
As noted they are suited to underfloor heating due to the increased surface area requires lower flow temp. You can use radiators but you need to oversize them to make up for it, if you are keeping you rads you may need to supplement them in each room.
You’re generally meant to set them on a timer, sometimes just leave it running 24/7 if it’s the underfloor system you are using.
By the time you add it all up it usually gets quite expensive.
You can get on to Bord Gais and ask them for plans in your area.
Or you can look at getting one of the LPG tanks that they mount underground which would free up your back garden.
Or move the oil tank.
Speaking of fridges in reverse…
There are a few other twpes that don’t use the ground- one uses air/sun to heat your hot water ( e.g. lvprenewables.ie)
and then there’s the air to air type which is like an air-conditioning unit in reverse. Popular in Sweden and probably more proven than the Ground Source. More suitable for retrofit. Panasonic and major brands do them
You’re still relying on mains electricity but if the efficiency irs right they can work well.
However the first step is to insulate as much as possible.
My BiL did ground source in a new build and in hindsight regrets it. Going for more insulation means there’s much less to go wrong. The lads in this industry in Ireland tend towards the cowboy variety
Why didn’t you get a surveyor to do it,I wouldn’t expect a surveyor to be an architect and vice versa,its the biggest single investment you will ever make and one for which you will likely be paying back over 20-25 years & for the sake of €400 I would get in someone who does this day in day out.
He does surveys too, and I paid him.
Thanks for the feedback guys.
I’ll probably stick with the oil until I can save up to change it.
I want to put a stove in where the open fire is in the sitting room. I did that before and it was pretty straightforward if I recall correctly. The heat from it was amazing.
You should look at an air to water system. We put one in last year and are very happy with it. Previously we had LPG and it cost me €3,000 over the winter. When doing an extension we looked at the air to water system. We mostly have underfloor and radiators in the old upstairs part. My increased electricity bill was for €800 over the winter for a house of 3,200 sq feet that was also drying out the plaster. Hot water in the summer is costing me about €20 per month and we have it 24/7. We found the LPG was a pain in the ass. Poor customer service and when it ran out once they took 3 days to deliver more.
Before you look at anything like that though, you really need to look at insulation and air tightness. During the renovation works we discovered that the hot water feed from the boiler was barely under the ground and that was why the boiler needed to stay on so long. If we had it on 24 hours a days it would never come up to temperature and turn off.
I looked that option up, but it seemed to be for underfloor heating. I know you mentioned you had underfloor and radiators, but would it work with just rads? Also, this is just a 1000 sq ft semi… Would it be overkill ?
Wow there is a oil tank outside your back door? Whatever science it is using, isn’t that oil tank dangerous for your house??? At least it shouldn’t be that close to your house.