Druidic Dabblings and General Twaddle !!

[Lancs Lad]

The thing you don't know/realise with ground source heat pumps is the amount of time the immersion is actually on during normal running. You'd be surprised how often they can be on the only way to know for sure is to meter the electric supply to it and monitor it.
The thing with rhi payments etc is that they have muddied the waters between greener energy or what many believe they are getting "free heating". Renewables may well be greener for the planet but to get your money back for the installation cost you've got to run it 24/7 ffs and even then you're looking at break even.

Check out the size of the chip pile outside a certain well know AG contractor near here...and his chimneys...since when did tractors need 24/7 heated sheds

 

[V8Druid]

45-50c is the water temp in the rads...not the room 50c would be lobster temp.

I appreciate the rads're a lot hotter than the air temp., but 50C in the hot water system'd be a tad on the hot side for a shower/bath
with rad.s at a constant 45-50c, rather than getting heated/allowed to cool/heated, you'd probably end up opening the windows .... but if the heat is constant and 'free' ..... what the hell

 

[V8Druid]

Check out the size of the chip pile outside a certain well know AG contractor near here...and his chimneys...since when did tractors need 24/7 heated sheds

know a fella round here has all his barns/outbuildings heated 24/7 to use up his 'quota ' to get his money ... ****ing crazy state of affairs

 

[fred]

Is the FIT still limited to to 4kva for domestic @fred ..... a roof full is gonna produce a lot more than that

there is no FIT for solar anymore.

Heat pump FIT is pretty good though especially ground source.

 

[fred]

45-50c is the water temp in the rads...not the room 50c would be lobster temp.

i dont think a normal 15kv heat pump would have enough power to bring all the rads up to even 35c, it takes it a good hour to get a fully insulated water cylinder to 50c.

 

[fred]

the way to look at heat pumps is their CoP efficiency rating. Air source are 3/4:1 and ground source 4/9:1 meaning for every £1 in electric you pay to spin the pump you get between £4 and £9 of heat free.

If you can mitigate your electricity costs with a lot of solar and insulation in the house it shouldnt cost you anything to run and you make a small profit out of the RHI payments.

 

[GazCro]

the way to look at heat pumps is their CoP efficiency rating. Air source are 3/4:1 and ground source 4/9:1 meaning for every £1 in electric you pay to spin the pump you get between £4 and £9 of heat free.

If you can mitigate your electricity costs with a lot of solar and insulation in the house it shouldnt cost you anything to run and you make a small profit out of the RHI payments.

I've always been under the impression air source is 3:1 as you say and ground 4:1. The thing is if you building new or renovating and bringing a property up to or above current regs you can design you're whole system to suit. There not gonna be the replacement for oil or gas boilers without a lot of other work for most people though.

 

[Smiffy]

Not strictly true, Fred. There are quite a few systems out there which use profiled insulation and a dry screed element which can get you down to around 50mm above FFL. Granted, the thermal efficiency/heat loss to the screed will be greater than going for 150mm of XPS or PU insulation, but they fill a gap in the market where floor height is an issue - particularly in retrofit.

HTH

Robert

I've got an after market system like this fitted to my house.
Just panels stuck down to the existing concrete floor.
It is really good and I'd definitely recommend
I don't know what the loss is from having no insulation under it but it's economical to run over radiators. So can't be that bad

It wouldn't work aswell with a ground source feed though I don't think.

Because there is no thermal mass it's more like radiator heating in that it heats and cools quicker so we run the thermostat on the same pattern as you with radiators. Having it on all the time doesn't really work.

 

[Left hooker]

Had delivery today of oil 500l then hang on to see if price drops but 41p per today compared to the emergency 100l at 75p at weekend
As for renewables house roof face east and west so solar or pv on roof out of the question and no room for slinky's or borehole ground source
And air source I'm not sold on and don't have anywhere I could put immersion tank coupled with the fact I have timber suspended floors so no under floor heating
Can't beat oil for running my place 60° water at kitchen sink and around 40° by time it hits the shower at far end and all instant hot water

 

[V8Druid]

there is no FIT for solar anymore.

Heat pump FIT is pretty good though especially ground source.

so no 4kva limit then?? ... you'd really need a wall or two to make use of a big array then .... could also get 7m+ x 2m+ on the roof the black shed too for extra input and that is nigh on dead south.... could even juggle the orientation of said new shed to be due south too , but'd be a PITA for any further easy extensions to it if I did that ... anyone know what sort of generation capacity 127m2 would give you ??

 

[GazCro]

so no 4kva limit then?? ... you'd really need a wall or two to make use of a big array then .... could also get 7m+ x 2m+ on the roof the black shed too for extra input and that is nigh on dead south.... could even juggle the orientation of said new shed to be due south too , but'd be a PITA for any further easy extensions to it if I did that ... anyone know what sort of generation capacity 127m2 would give you ??

Trouble with solar is there's next to no FIT but panels are still at ott cost they were when FIT was good.

 

[TiltyShaun]

so no 4kva limit then?? ... you'd really need a wall or two to make use of a big array then .... could also get 7m+ x 2m+ on the roof the black shed too for extra input and that is nigh on dead south.... could even juggle the orientation of said new shed to be due south too , but'd be a PITA for any further easy extensions to it if I did that ... anyone know what sort of generation capacity 127m2 would give you ??

There is a 4kva rule that the line operators have to allow you to connect. Over 4kva needs a permit from the line operator to confirm the network can handle what you are sending into the grid if you want a grid tie!!

 

[Smiffy]

Had delivery today of oil 500l then hang on to see if price drops but 41p per today compared to the emergency 100l at 75p at weekend
As for renewables house roof face east and west so solar or pv on roof out of the question and no room for slinky's or borehole ground source
And air source I'm not sold on and don't have anywhere I could put immersion tank coupled with the fact I have timber suspended floors so no under floor heating
Can't beat oil for running my place 60° water at kitchen sink and around 40° by time it hits the shower at far end and all instant hot water

They make trays to sit between joists on suspended floors to carry the underfloor heating loops
Probably a tad pointless as floor boards will act as an insulator

 

[fred]

Trouble with solar is there's next to no FIT but panels are still at ott cost they were when FIT was good.

kits are cheap now, 4kw complete system, is £4k

New Build/Self Build In-Roof (BIPV) Solar Kits | Plug In Solar

Plug In Solar - Your DIY Solar Energy Solution

www.pluginsolar.co.uk

 

[Left hooker]

They make trays to sit between joists on suspended floors to carry the underfloor heating loops
Probably a tad pointless as floor boards will act as an insulator

Plus I have slate tiles in some rooms and fake wood flooring on top of the rest

 

[pettsy]

Will shortly be installing ufh on the ground floor of my house. 1st and second floors will be having radiators as the in-floor trays were hard work last time I used them.

 

[fred]

Will shortly be installing ufh on the ground floor of my house. 1st and second floors will be having radiators as the in-floor trays were hard work last time I used them.

what we do for first floors is counter board the floor so it exactly fits the trays, the pozi joists invariably never quite work not to mention steels etc. Counter board with 2x2 makes it a doddle and also keeps they away from services. We account for the extra build height and make the ceilings higher to account.

 

[fred]

There is a 4kva rule that the line operators have to allow you to connect. Over 4kva needs a permit from the line operator to confirm the network can handle what you are sending into the grid if you want a grid tie!!

people installing 8kw are not having them grid tied as there isnt any point as they dont pay you anymore, its purely energy storage. Some use thermal stores instead of batteries. All depends what your needs are really.

 

[fred]

so no 4kva limit then?? ... you'd really need a wall or two to make use of a big array then .... could also get 7m+ x 2m+ on the roof the black shed too for extra input and that is nigh on dead south.... could even juggle the orientation of said new shed to be due south too , but'd be a PITA for any further easy extensions to it if I did that ... anyone know what sort of generation capacity 127m2 would give you ??

no limit just don't grid tie them. If you have spare land, ground setups are cheap to put up. There is acre upon acre of them around stratford upon avon.

 

[V8Druid]

no limit just don't grid tie them. If you have spare land, ground setups are cheap to put up. There is acre upon acre of them around stratford upon avon.

there are fields of 'em round here in certain areas too ... often on good productive arable land ....
one guy wanted to put some on a steep hillside, not far from one such area and was refused planning .... perfect spot for 'em .. south facing and unusable land for much else

people installing 8kw are not having them grid tied as there isnt any point as they dont pay you anymore, its purely energy storage. Some use thermal stores instead of batteries. All depends what your needs are really.

so you'd have to have some form of storage then @fred -- like a wall or two? to make any use of the power they produce?
How do you separate this from your house/grid system and still be able to use it / not draw off the grid??
I know little about this stuff as once I'd sussed, years ago, it was a non starter, then, I've not taken a lot of notice since
presumably the wall battery banks are series-ed and put out 240v ? or are they paralleled and put out 12/24v for inversion to 240v?
what's the lifespan of a wall ?
I am a complete luddite on how this stuff works