New Build - Heating System

January41

Hi, I'm planning a new build in early 2014 and am receiving very conflicting advice about the heating system I should put in and would appreciate any insight you may have so I can actually make a decision.

1850 sq ft dormer house
Fairly decent insulation spec
No underfloor heating
11 radiators
Non boiler stove in the living room

Option 1 Conventional
Solar panels for hot water
Oil fire central heating - heating and/or hot water. The heating will be zoned for upstairs and downstairs, timed etc (not sure whether to have individual thermostats on radiators or whether these would be centrally controlled).

This is quite a simple system which fits our requirements now I.e. no kids, work 9 to 5, some days from home.

Option 2 Renewable
Air to Water Heat Pump for water and heating
My concerns here are:
I have no fall back heating system except for the stove in the living room
I've heard that ATW is suitable for ugh only?
Expensive unless properly installed
Special radiators required

I presume I could use solar panels in conjunction but this would make the initial spend quite high - I love the idea of this product but am so wary of it given all the mixed reviews!

Any comments appreciated!

kboc

January41 wrote: »

Hi, I'm planning a new build in early 2014 and am receiving very conflicting advice about the heating system I should put in and would appreciate any insight you may have so I can actually make a decision.

1850 sq ft dormer house
Fairly decent insulation spec
No underfloor heating
11 radiators
Non boiler stove in the living room

Option 1 Conventional
Solar panels for hot water
Oil fire central heating - heating and/or hot water. The heating will be zoned for upstairs and downstairs, timed etc (not sure whether to have individual thermostats on radiators or whether these would be centrally controlled).

This is quite a simple system which fits our requirements now I.e. no kids, work 9 to 5, some days from home.

Option 2 Renewable
Air to Water Heat Pump for water and heating
My concerns here are:
I have no fall back heating system except for the stove in the living room
I've heard that ATW is suitable for ugh only?
Expensive unless properly installed
Special radiators required

I presume I could use solar panels in conjunction but this would make the initial spend quite high - I love the idea of this product but am so wary of it given all the mixed reviews!

Any comments appreciated!

I certainly don't mean to be rude but you need a person who knows what they are talking about, I think you are putting the cart before the horse.

Check this web site or this magazine and find a consultant who knows their stuff willing to guide you through this minefield. Make sure they do a PHPP at very least.

Good luck

shane0007

You are also going to have to meet the requirements of Part L for the build. Generally the only way you will meet this is with a heat pump so your options will most likely be factored around this option. That is of course if you wish to have your house certified upon completion.

fclauson

shane0007 wrote: »

You are also going to have to meet the requirements of Part L for the build. Generally the only way you will meet this is with a heat pump so your options will most likely be factored around this option. That is of course if you wish to have your house certified upon completion.

Nope a HP alone will not meet Part L - you need to look at getting a ore build ber to ensure compliance

Also solar thermal are not economic in a new bud they have an ROI of over 20 years

Also one question why not UFH ?

shane0007

I did not say a heat pump alone. I said the only way of meeting the requirement will be with a heat pump, i.e. a heat pump will have to be in the equation as the OP was seemingly dismissing HP technologies & UFH. UFH will also have to be in the mix if HP is being used.

BryanF

shane0007 wrote: »

You are also going to have to meet the requirements of Part L for the build. Generally the only way you will meet this is with a heat pump so your options will most likely be factored around this option. That is of course if you wish to have your house certified upon completion.

not true what about log gasification boiler or pellet boiler?

fclauson

Or PV or wind or hydro elec

shane0007

For most builds, these technologies are generally not suitable.
Wood gasification, most people don't want to load up all the time. A lot of work, a lot of storage & a good low MC supply required.
Wood Pellet, well supply, storage & reliability very questionable.
PV, how can you depend on it? Expensive banks of batteries required to supply electricity at night.
Wind, as PV but also most sites would not be suitable as they do not have the required wind hours per annum. Also special planning requirements to go above 13m.
Hydro, extremely rare to have a site suitable.

So we are back to HP's or a combination of other technologies to compliment the HP.

rodzer

or oil boiler, difficult but not impossible to achieve compliance

shane0007

rodzer wrote: »

or oil boiler, difficult but not impossible to achieve compliance

Not a hope!
Oil is not considered as a renewable source therefore it will not be counted towards the Part L requirement.

rodzer

shane0007 wrote: »

Not a hope!
Oil is not considered as a renewable source therefore it will not be counted towards the Part L requirement.

Yes my doubting friend there is hope. I have got a number of new builds to comply with Part L 2011 recently. The renewables req. is met by solar panels and also sometimes a biomass stove but the main space and water heating systems are oil.
Get a provisional BER done.

shane0007

rodzer wrote: »

Yes my doubting friend there is hope. I have got a number of new builds to comply with Part L 2011 recently. The renewables req. is met by solar panels and also sometimes a biomass stove but the main space and water heating systems are oil.
Get a provisional BER done.

I bet that installation has a nice solar fraction!
To get over the line with solar, it would have to be huge.
What are you doing with all excessive heat produced during the summer months with little or no demand? After all, you are meeting Part L for space heating, which is generally not required during summer months!
Any renewable can meet Part L on its own but is it practical?

rodzer

shane0007 wrote: »

I bet that installation has a nice solar fraction!
To get over the line with solar, it would have to be huge.
What are you doing with all excessive heat produced during the summer months with little or no demand? After all, you are meeting Part L for space heating, which is generally not required during summer months!
Any renewable can meet Part L on its own but is it practical?

DEAP won't allow you to oversize the solar system in the first place. There is a rad. for dumping the heat but its never needed as the gang of teenagers use all the water every day.
Yes, they wash themselves even in summer
Like I said, get a prov. BER done.

shane0007

rodzer wrote: »

DEAP won't allow you to oversize the solar system in the first place. There is a rad. for dumping the heat but its never needed as the gang of teenagers use all the water every day.
Yes, they wash themselves even in summer
Like I said, get a prov. BER done.

You said you met the requirement with solar on a number of new builds. What was the size of the dwelling & what was the size of the solar installation that met this requirement?

It had nothing to do with DEAP not allowing you to over-size. That statement just does not make sense. By inputting the details of the installation, will determine the part L satisfaction. It will either meet it or it doesn't.
I am only asking how you got a number of installations over the line with solar & what provisions you make for stagnation & over-sizing. A radiator on that size of a system would not suffice. Also the location of the radiator would also be a factor. If its in the attic, during a hot day, what would be the air temp of the attic space & therefore how would a radiator dissipate heat into a warm space.

rodzer

shane0007 wrote: »

You said you met the requirement with solar on a number of new builds. What was the size of the dwelling & what was the size of the solar installation that met this requirement?

It had nothing to do with DEAP not allowing you to over-size. That statement just does not make sense. By inputting the details of the installation, will determine the part L satisfaction. It will either meet it or it doesn't.
I am only asking how you got a number of installations over the line with solar & what provisions you make for stagnation & over-sizing. A radiator on that size of a system would not suffice. Also the location of the radiator would also be a factor. If its in the attic, during a hot day, what would be the air temp of the attic space & therefore how would a radiator dissipate heat into a warm space.

Dwelling 260m2,
Solar aperture area 6m2.
Heat dump rad. in heated space.
I'm going to bed now, good night.

shane0007

rodzer wrote: »

Dwelling 260m2,
Solar aperture area 6m2.
Heat dump rad. in heated space.
I'm going to bed now, good night.

Just so we are singing from the same sheet, this thread is talking about meeting Space Heating requirements for Part L for New Builds & not meeting grant approval for SEAI requirements for domestic hot water.

6m solar panel. The sun in summer can do no more than circa 1,000 watts per sqm per hour in Ireland in summer months for Ireland. In winter, it's circa 500watts per hour but we have far less sun hours in winter.
So that's approx 3kw/hr @ 100% efficiency. The best panel in the market has an N0 efficiency of approx 75% so that would reduce your panel to an output of approx 2.25kw per hour. Even super insulated, a 260sqm house requires more than 2.25kw per hour for space heating!
It also does not comply for new builds.
It will just about comply for SEAI requirements for dhw alone which I think this is what you are confusing with.

What results have you achieved on all these new build installations with regard to the annual kwh input from the solar?

sydthebeat

Shane I'm not sure where you are coming from on this but there are many ways to comply with the renewable aspect of part l.

The practicality of each option is relative to the client AND dwelling.

if using solar collectors in a large house, its possible to allow a certain portion to be added as space heating if the system is oversized for the occupancy.

In most cases that I see, compliance is met by solar collectors, wood dedicated stove and oil based boilers.
If there is a cheap steady supply of good quality wood available, gasification boilers are a much more suitable energy source for large dwellings than heat pumps.

shane0007

I agree with that but I still cannot see how 6m2 of solar will get a new build compliant.
Of course many technologies can be used & many are, usually a combination of many. But most have practical limitations. I am merely making the point that it is not just about banging in any given technology & it's job done. You have to look at what is suitable for the masses. IMHO the HP along with air tightness, & possibly some others meets this requirement.
6m of solar will not & this misleading.

shane0007

sydthebeat wrote: »

In most cases that I see, compliance is met by solar collectors, wood dedicated stove and oil based boilers.

Oil based boilers do not contribute to meet the renewable side of Part L.

fclauson

shane0007 wrote: »

...
PV, how can you depend on it? Expensive banks of batteries required to supply electricity at night.
...

So we are back to HP's or a combination of other technologies to compliment the HP.

PV - you go grid connect - I have pushed around 1800 kwh back into the grid of the 3100 I generated - I get 8c for it but then re purchase that at the night rate of 8 c so it's a zero cost battery (actually its €40 to hire the battery per year as I have to pay an additional charge to ESB to avail of the night rate tariff)

I even cooked my Christmas turkey for nothing as Christmas Day in Wexford was very sunny!!!

HP alone is a passive house like mine WOULD NOT have met the part l requirement I had to add the PV to do that ( also see letters in PH+ re what a BCO said about that )

sydthebeat

shane0007 wrote: »

Oil based boilers do not contribute to meet the renewable side of Part L.

I didn't say it did, I said the combination of the three as the heating system is what's most commonly used to comply with part l.

Similarly a low efficiency air to water heat pump in a lot of cases wouldn't be enough either. Heat pumps loose serious efficiencies when our comes to water heating.