New House build compliance

clauduledus

Hello all,

I am starting the build of a new house wooden frame, insulation between joists and insulated plasterboard, dryline atc. Architect is pretty happy that no/ very little cold bridging will occur. So we are talk a fairly well insulated house.

The house is about 1700 square foot. We are going through the rigmarole of the BER/Part L and the minute. I originally wanted a wood burning stove and thought i would be able to supplement with a small bit of solar thermal. Also this would have run my rads at circa 60-80 degrees.

The boys doing the BER/Part L say that we need to think about doing Air to Water system because the amount of solar needed to make above complaint is massive. Also they were suggesting solar PV but from an electrical point of view (me being in the business) is to much messing

My questions are
Is the air to water a low temperature ie 40 degrees
what size unit (obviously not knowing the specs) Approx. would i need and how much would they cost.

Any help would be great or even suggestions on a new course of action. Many thanks for reading. Free Tea for help once house is built.

Metric Tensor

Air to Water - as you say - is only suitable for low temperature, underfloor heating set ups. There are specialist radiators designed for low surface temperature use but I've never seen them used in this context and I'd doubt they are useful.

Your assessor is correct regarding a requirement for a possibly oversized amount of solar panels to get compliance when using a non-renewable boiler with rads. However, it is possible to make the building compliant using this process - you just end up with a lot of solar panels on your roof and usefulness of this number is questionable.

If you want to stick with rads (which I would in my own house - although I'm in a minority) you could have two different renewable systems supplementing an oil boiler. i.e. Solar Panels + Wood stove or some such. I would have thought if you were an electrician the cost of installing PV would be lower than most other people and hence a viable route from a cost-benefit approach.

Mind you if you're an electrician a heat pump would be down your street too!


P.S. - just re read the OP - were you planning to run the rads from a back boiler on the stove? And also the hot water?

clauduledus

Metric Tensor , many thanks for the response.

I was planning on running an exterior wood burning stove. The stove in my sitting room will not have a back boiler. The assessors are giving me figure in the region of 15k for the heat pump set-up which is way above budget. They are also saying the solar panel set-up will be expensive. I think i need to go price the two different option then decide.

I don't have the option of underfloor because it is a wooden frame up on stilts, built into a hill. I am just weary that the heat pump (low temperature set-up) will not work great with wall mounted radiators

Metric Tensor

I could be corrected on this but I THINK ... Oil Boiler + Rads + Solar Panels has a slightly lower up front cost than Heat Pump + UF.

I have no idea how Low Surface Temp rads would factor into that.

donalh087

I am in the same situation as you OP. -snip- The plan is to have the 'living side' underfloor heating and the 'sleeping side' with rads. The cost seems close enough to traditional systems.

donalh087

Ignore the post above - it makes no sense after someone else has edited it.

BryanF

Hi please read Forum charter http://www.boards.ie/vbulletin/showthread.php?t=2055036302

edit See section 2 & 3

CaraK

Stumbled upon this last night it's a good cost comparasion of the different options taking into account the initial capital costs

BryanF

CaraK wrote: »

Stumbled upon this last night it's a good cost comparasion of the different options taking into account the initial capital costs

Cara can you Post the source assuming it's nots not a business thanks

CaraK

BryanF wrote: »

Cara can you Post the source assuming it's nots not a business thanks

It is a business ,it's from the UK site of one of those German house builders like huff haus but not them.

Metric Tensor

It's a clever idea and something I'd like to show my own clients but it is heavily dependant on the prices used for electricity, gas and pellets. Without providing that information alongside the chart it's no good!

I would agree in general terms with some of the contents and disagree with other bits!

delfagio

Just to throw my two cents in, Don't rule out oil condensing boiler. If the house is well insulated, high level of airtightness and makes good use of solar gain and orientation, then oil will be extremely cheap to run the house for its heating.

Personally, there is very high costs for A2W and Geothermal both on initial investment and installation costs and also to be fair they don't appear to be cheap to run per year. However that is my own opinion.

For us, the cost for installing the oil was approx 3,000euro which is a lot less up front investment than say A2W or Geothermal. That 3000euro includes 1150euro for Grant Condensing Oil Boiler, 580euro for fill of oil, and 1400euro for oil tank, and plumber to connect up and commission it all.

We have UFH throughout the house both upstairs and downstairs.

Very pleased with how it all works, we do have large south facing windows which take the free heat from the sun to our advantage and our heating is very low cost per year.

Metric Tensor

How much solar did you require alongside that delfagio? Just to give the OP an idea.

delfagio

I have a 1 Thermodynamic Solar Panel for my hot water with a 300lt Hot Water Cylinder and also a 1kW PV Solar Panel array.

clauduledus

Lads, thanks for the info. also thanks thanks donalh087 for suugestion.

delfagio: interesting mix there. I think the oil boiler and the wood burning stove would be something very similar and would require a similar amount of solar set up along side it. Would i be correct in thinking that. Thanks for the post. Not sure how a thermodynamic solar panel differs so ill start doing the research. What way does the solar PV work out.
If ya could maybe you could give me a guide price you paid. But if your not happy doing that thats grand. Thanks for the help again.

delfagio

Hi Clauduledus, The 1kW Solar PV and Thermodynamic Solar panel and 300lt Cylinder set me back approx 8,000euro. As previously mentioned in another post the oil condensing boiler and associated works cost me approx 3,000euro.

The Thermodynamic Solar panel for me is working very well and we are very pleased with it. Basically it is providing 100% all of our hot water needs rail, hail, sleet, snow, ice, frost or sunny weather. I need no oil or back up to heat our domestic hot water

Look them up online for more info or also look on boards.ie. There were previous threads on them,

Metric Tensor

Just to say solar thermodynamics is actually a heat pump so it will always give hot water because even if it had no added efficiency it would act as an immersion.

I've never encountered one in a DEAP assessment. Was your DEAP assessor allowed use renewable efficiencies for the solar thermodynamics delfagio?

delfagio

Metric Tensor wrote:

Just to say solar thermodynamics is actually a heat pump so it will always give hot water because even if it had no added efficiency it would act as an immersion.

Yes Metric Tensor part correct. It is more a hybrid system between Solar and Heat Pump

Metric Tensor wrote:

I've never encountered one in a DEAP assessment. Was your DEAP assessor allowed use renewable efficiencies for the solar thermodynamics delfagio?

The BER Assessor liaised with the Thermodynamic Company on this one also as he had not come across before either for DEAP. It was allowed use renewable efficiencies. The overall Renewable contribution was approx 2kWH/m2/year

delfagio

delfagio wrote:

The BER Assessor liaised with the Thermodynamic Company on this one also as he had not come across before either for DEAP. It was allowed use renewable efficiencies. The overall Renewable contribution was approx 2kWH/m2/year

Also Metric Tensor, the main reason that it falls down in DEAP, is due to its size. The square area of the panel is only 1.6m2 as the Solar panel is only approx 0.8m x 2.0m and only 1 panel is required for providing all domestic hot water needs.

Metric Tensor

I'm not an expert on these units delfagio -

The little I've read seems to suggest that the COP is quite low and hence they are primarily a electricity powered heat pump supplemented in a small way by some solar/thermal gain.

I have not looked at the figures myself though so I am open to be corrected - you have one installed so you know better than I do how the unit works in the real world and what effect it has on the electricity bills.

If I get a chance in the coming weeks I'll try to read up a bit on the units and might come back to you with any queries I have - you're the first person I have had contacted with who actually has one installed.

Calahonda52

clauduledus wrote: »

.. Also they were suggesting solar PV but from an electrical point of view (me being in the business) is to much messing

Why, as someone the business, do you say that?

http://www.boards.ie/vbulletin/showthread.php?p=103026535#post103026535

clauduledus

Hi Calahonda52. Not sure what relevance that thread has to solar PV.

I dont know the setup of the PV to be fair, I need to do more reading but i imagine the interface between the house and the ESB needs to be considered. Possibility of back feeding the ESB lines from the solar produced in the house, but i am sure there is a relay that would sort this and ESB have already dealt with this. Any advice here would be most appreciated.