Renewable heating systems??

castleview

Hi,

Hoping to start building a new 3500 sq ft house shortly and trying to decide the best way forward with regards to heating systems. Its starting to wreck my head at this stage. I hope to achieve the following u-values, and would prefer to spend more on the insulation and less on the heating

Walls - 0.15
Ground Floor - 0.12
Roof - 0.13
Windows - 1.3

I am going with undefloor heating throughout but when it comes to deciding on a heat pump, I am undecided and would appreciate any feedback / opinions. If the house is well insulated and airtight, is it a waste of money to spend in the region of €22 k on geothermal, or would I be better going with Air to Water or wood pellet burner?.

Decisions, decisions!!

Thanks!

Leadership

I am/was in a similar situation with a similar build spec (2500sqft house). I have been to almost 100 suppliers & so called experts but the prices are crazy in Ireland for this relativly cheap technology and they contradict each other.

In the end I am just going to use an oil boiler put 10k in a high interest account and wait for some reasonable prices in the few years time.

What I am doing is putting up solar that contribute to the heating and wood stove with a back boiler attached to a 800 ltr thermal store.

Mike2006

I have more or less the same size house to you and am going to start building soon.

I have opted for a cheap 35kW Wood pellet boiler (~€4k to €5k) and if the demand is high or it costs too much to run, I will look at replacing maybe in 5 yrs or so.

I too think that the geothermal outlay is a bit high at the moment especially as our electricity is index linked to oil in this country. I am also of the opinion that a heatpump will prob fail within the 20yrs payback time thus incurring another high cost... (just my opinion)

I hope to reduce the demand for heat as much as I can by insulation/airtightness/good workmanship and then I should not need an expensive heat source.

Hope this helps.

Mike.

Dingleman

Hello castleview

I went through the same nightmare that your currently going through last year, in the end, i went with a geothermal heat pump, with underfloor heating downstairs and rads upstairs. I was lucky enough to get a grant of €6,500 from SEI, but, i understand that there is no grant available now, I'm happy enough with the system, the undefloor is great, but, i'm not so happy with the rads upstairs, they dont heat up as much as i would want on cold winter nights, hence, the other half is not happy

If i was building again, i think i would go with a good boiler and very good insulation, with a machanical recovery unit (which i also have in this house) the cost of the geo... is too much to justify

if you want to have a chat, i'll send you my mobile

sp

Zilog

My own view is to spend money on airtightness and insulation.

After that, a high efficiency 'conventional' water based system - condensing gas or oil boiler - with efficiency over 90%.

If and when superior alternative technologies are available, they will still probably use water as the transfer medium, meaning your emitters (radiators or underfloor) should still work.

If you look at a heat pump, ensure that it is "Arctic rated" type, rather than the cooling type heat pumps running in reverse mode, which are not designed to take heat out of cold winter air. Otherwise, the units may freeze up and need to go into defrost mode when you need the heat most.

castleview

Thanks for the replies. Still not sure what Ill go with, will keep researching

Jloner2

Hi all,
Ive got my quote for UFH with 8kw heat pump down to about €17k. UFH is coming down a bit too.
What I really really want to know from anyone on here with a solid block build ~2000sq/f with cavity insulation running on a 8kw heat pump is how much your ESB bills are???
Talking to a guy i know is paying €500 each bill for a 3000sq/f house. Thats a lot of oil reguardless of prices

sailjerry7071

Does anyone have any experience/knowledge of thermodynamic solar panels/systems, ie using refrigerant gas and a compressor? I saw the Energie installation at Waterford Self-build expo and it looked impressive. we are thinking of using a single panel unit for hot water and a 4 panel unit to supply a heat battery in our MHRV.