Geothermal Heating

Geratron

Hi guys, My wife and I are in the process of building our house. The timber is almost on the roof. The house itself is 3,400 sq ft. We have decided to put geothermal heat pump with underfloor heating into the house. Our installed reckons he can heat the house and supply hot water 24/7 for €1,000 per year which sounds pretty good. The heat pump is going to be an IVT 11KW heat pump. Does anyone have any experience with these heat pumps and does the price per year sound achievable?

Thanks, Gerry - Donegal

kboc

Geratron wrote: »

Hi guys, My wife and I are in the process of building our house. The timber is almost on the roof. The house itself is 3,400 sq ft. We have decided to put geothermal heat pump with underfloor heating into the house. Our installed reckons he can heat the house and supply hot water 24/7 for €1,000 per year which sounds pretty good. The heat pump is going to be an IVT 11KW heat pump. Does anyone have any experience with these heat pumps and does the price per year sound achievable?

Thanks, Gerry - Donegal

Gerry, with all due respect you could possibly be too late for considering a heat pump.

Installers of heat pump need to be more responsible and give you the full joined up picture. Unless your house has a cavity wall of 6/8 inches (or another methods equivalent), 6 inches in floor insulation and 10 inches of insulation in roof along with the key issue of airtightness as a minimum, then that installer is selling you a pup!

A few things i noticed with your info;

1.
11kw might struggle to heat your house unless extremely well insulated and airtight

2.
your installer "reckons he can heat" your house. When you are investing possibly 20,000 euro "reckons" is not good enough.

Be cautious of the heat pump approach.

It is possible, i have the insulation mentioned above in a house of similar size to yours (3,500 sq ft) and a 12kw heat pump cost £50 to heat my house in January.

I live in Derry and you can come and look at mine if you like, a small visit might be worth it in long term.

PM me if you are interested

Good Luck

Geratron

Hi, thanks for the reply. Our house has a wall cavity of 125mm and we have put 100mm (approx 4 inches) insulation in the cavity. We will be putting 100mm of insulation below the underfloor heating and we will be putting a lot of insulation in the roof also.

We will be plastering the internal and external walls of the house with sand and cement which will give a good degree of airtightness. We will also be putting a strip af insulation between the underfloor heating and the walls to stop the heat going into the walls.

Thanks for the offer to look at your house. £50 for January was pretty good.

Do you have continuous hot water? What if three or four shower are being used at the same time, is there still continuous hot water. Is your hot water system pressurized?

Sorry for all the questions but is good to ask people who have experience with the same system in their house.

Gerry

holdfast

your house does not meet min building standards with that insulation. more than likely you will be spending more than 1000 euro a year to heat your house. You need to look again at those figures before you spend that kind of money on geothermal and put some money into insulation. Your house may not even meet 2007 standards. Either talk to your building professional if you have not (or get one), if you have and they have recommend them ditch them and get some one else.

agree with kboc on the sales man reckoning. I have geothermal and would not recommend putting into every house else less the house is well build. Sorry but I dont mean to be rude but your is more than likely not by current standards.

pm for information if you wish

best of luck

bruschi

holdfast wrote: »

your house does not meet min building standards with that insulation. more than likely you will be spending more than 1000 euro a year to heat your house. You need to look again at those figures before you spend that kind of money on geothermal and put some money into insulation. Your house may not even meet 2007 standards. Either talk to your building professional if you have not (or get one), if you have and they have recommend them ditch them and get some one else.

agree with kboc on the sales man reckoning. I have geothermal and would not recommend putting into every house else less the house is well build. Sorry but I dont mean to be rude but your is more than likely not by current standards.

pm for information if you wish

best of luck

have the standards changed recently? I had thought that the minimum standards were an 80mm cavity insulation and 100mm floor insulation? I hadnt seen part L changed recently anyway. 2007 standards were even below those thciknesses as well, so 100 in floor and wall I thought would certainly meet the minimum.

dos29

holdfast wrote: »

your house does not meet min building standards with that insulation. .................. You need to look again at those figures before you spend that kind of money on geothermal and put some money into insulation. Your house may not even meet 2007 standard.

Really? I think you might be off track a bit with that...

bambampop

Be very careful of using a heat pump to heat your domestic hot water. Sized correctly they can work quite well with underfloor heating but because your domestic hot water has to be raised to circa 60 degrees (only 30-40 with underfloor heating), it requires a lot of energy. It can have a massive effect on the co-efficient of performance (the performance measurement for heat pumps) to the point where it is more efficient to just use an immersion heater.

Completely agree with the above posters about the supplier reckoning it will do the job. Not trying to put you off them completely but they need to be sized by a professional.

p.s. you don't need heating/hot water 24/7