openspaceman wrote: ↑Sat Jul 30, 2022 7:46 pm
What I forgot to say is I order haggis and smoked salmon from Scotland which arrives next day by courier. The box is lined with that reflective multilayer insulation but inside with the meat are gel packs (heat sealed bags) of water and a polymer that has a lower freezing point, they arrive still fairly solid. If I order more I shall try and see what temperature they freeze at but in other respects they would be fine in a freezer.
Good idea... I'll try it.
We go to Findlays of Portobello for our Haggis when we are up there (several times a year.) I sometimes get Arbroath Smokies by mail-order... except that the last time they forgot my order and then just stuffed them in a Jiffy Bag and sent them first class post!
A
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AE-NMidlands wrote: ↑Sat Jul 30, 2022 6:17 pm
I'm starting to understand...
Although a salt solution has a lower SH than water (due to the salt displacing the water super-molecules) in fact you push the water phase change down to a useful freezer temperature.
I think I have got it now... I read previous posts as saying that the salt crystals coming out of the brine was the phase change being exploited.
(Apart from some strange compounds like CaCl2 and NaOH I had never encountered any latent heat associated with dissolution or solutes crystallising out..)
A
Our hot water heat storage is provided via a bit of kit that exploits the big gain in stored energy that you can get from changing the phase of a material. It uses sodium acetate, the stuff used in hand warmers that are charged by putting them in boiling water and triggered to discharge and give out heat by a small "clicker" inside the gel capsule. There's some secret source in the box that enables nucleation to be triggered automagically and to stop automatically as well. The result is a box that's pretty small but which stores as much heat as a ~210 litre water tank.
Best bit about it is that the heat losses are tiny. We went away for a week, with the thing switched off (for safety), came back and found we still had a "tank" of hot water as the thing had just sat there with the sodium acetate in liquid form and was only triggered to start turning back into a solid when we ran off some hot water when we got home.
What is the make/model of your heat storage thingy?
Also interested in this.
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AE-NMidlands wrote: ↑Sat Jul 30, 2022 6:17 pm
I'm starting to understand...
Although a salt solution has a lower SH than water (due to the salt displacing the water super-molecules) in fact you push the water phase change down to a useful freezer temperature.
I think I have got it now... I read previous posts as saying that the salt crystals coming out of the brine was the phase change being exploited.
(Apart from some strange compounds like CaCl2 and NaOH I had never encountered any latent heat associated with dissolution or solutes crystallising out..)
A
Our hot water heat storage is provided via a bit of kit that exploits the big gain in stored energy that you can get from changing the phase of a material. It uses sodium acetate, the stuff used in hand warmers that are charged by putting them in boiling water and triggered to discharge and give out heat by a small "clicker" inside the gel capsule. There's some secret source in the box that enables nucleation to be triggered automagically and to stop automatically as well. The result is a box that's pretty small but which stores as much heat as a ~210 litre water tank.
Best bit about it is that the heat losses are tiny. We went away for a week, with the thing switched off (for safety), came back and found we still had a "tank" of hot water as the thing had just sat there with the sodium acetate in liquid form and was only triggered to start turning back into a solid when we ran off some hot water when we got home.
It would be excellent if this tech could be incorporated into an electric central heating boiler. SWMBO & I were speaking about a related subject the other day. We have taken gas out of the equation by using the HW storage tank immersion coil. Surely it then makes sense to source a small electric retro fit boiler to keep the current rads in play? A boiler with phase change material built in to timeshift power use yet extend run time would surely be grail?
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
Joeboy wrote: ↑Sun Jul 31, 2022 7:45 am
It would be excellent if this tech could be incorporated into an electric central heating boiler. SWMBO & I were speaking about a related subject the other day. We have taken gas out of the equation by using the HW storage tank immersion coil. Surely it then makes sense to source a small electric retro fit boiler to keep the current rads in play? A boiler with phase change material built in to timeshift power use yet extend run time would surely be grail?
You can do this if you like. Nothing stopping you!
The main problem is that you’d need a very big storage system for space heating vs DHW (which uses a comparatively small amount of energy). People with boiler stoves often have 1000 or 1500L thermal stores so that the evening fire can heat the house the next morning. But there is nothing stopping you fitting a smaller tank with immersion and circulating the water round your wet circuit via a mixing valve.
I’m in it for the super-low standing losses!
We use little hot water day-to-day but occasionally and at short notice the Mrs will decide to have a bath. So we need 250L of hot water ready to go at short notice. We don’t have a DHW tank at the moment, a potential tank would go in the attic, so standing losses wouldn’t even contribute to warming the house in winter.
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Joeboy wrote: ↑Sun Jul 31, 2022 7:45 am
It would be excellent if this tech could be incorporated into an electric central heating boiler. SWMBO & I were speaking about a related subject the other day. We have taken gas out of the equation by using the HW storage tank immersion coil. Surely it then makes sense to source a small electric retro fit boiler to keep the current rads in play? A boiler with phase change material built in to timeshift power use yet extend run time would surely be grail?
You can do this if you like. Nothing stopping you!
The main problem is that you’d need a very big storage system for space heating vs DHW (which uses a comparatively small amount of energy). People with boiler stoves often have 1000 or 1500L thermal stores so that the evening fire can heat the house the next morning. But there is nothing stopping you fitting a smaller tank with immersion and circulating the water round your wet circuit via a mixing valve.
I’m in it for the super-low standing losses!
We use little hot water day-to-day but occasionally and at short notice the Mrs will decide to have a bath. So we need 250L of hot water ready to go at short notice. We don’t have a DHW tank at the moment, a potential tank would go in the attic, so standing losses wouldn’t even contribute to warming the house in winter.
The system already has two zone control in place on the wet circuit. The circulating pump is there. I guess it would be a very small, say 10 ltrs highly insulated tank with twin coils(6kw) so we can get a decent bit of response out of it. Flush the old system, install a filtration unit and hook in the top up pipe..
Edit, I wonder if it's possible to do a 4 immersion coil chamber drawing from a solar diverter (2 coils) and House (2 coils)
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
Would be nice to run off of a solar diverter in the shoulder months and be able to vary the power to it when on grid. First baby step made.
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
We need to remember that heat energy is the lowest form of energy (all energy ends up as heat) and therefore has the least value and therefore the least return on investment. Storing leccy yes but storing heat not so sure. Use stored leccy to drive a HP .
For most people (nobody on here i know) they just need to put on another layer and turn down the thermostat - I have a neighbour who goes around in a tee shirt and ALWAYS has a window or two open! Another neighbour had fitted yesterday PV+ batts ( iguess the EV will be next) and now they are making a real difference.
Ken wrote: ↑Sun Jul 31, 2022 10:46 am
We need to remember that heat energy is the lowest form of energy (all energy ends up as heat) and therefore has the least value and therefore the least return on investment. Storing leccy yes but storing heat not so sure. Use stored leccy to drive a HP .
For most people (nobody on here i know) they just need to put on another layer and turn down the thermostat - I have a neighbour who goes around in a tee shirt and ALWAYS has a window or two open! Another neighbour had fitted yesterday PV+ batts ( iguess the EV will be next) and now they are making a real difference.
We have 15 radiators in the house tagged back to a gch boiler.
Using the WBS and timeshifted storage heater(retro fitted) charging we managed to pull our gas use down by an outrageous amount last Winter. This Winter I am going to let all the storage heaters charge for the full 5 hour go faster period, assess and look towards a boiler change next year. It seems crazy to have all those wet rads sitting doing nothing especially as I could isolate the ones not needed due to the storage heaters and use the ones that SWMBO identifies as being good to have. This way the 12 or 14kW of energy from the electric boiler would be 'power to a point' and effective. I remain unconvinced on HP's as far North as I am but am very open to further learning/detail? It might just be easier to let Winter run & SWMBO feedback.
The game as I am playing it now is towards gas off and disconnected.
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees
It would also be nice to be able to adjust the power input to the heater flow unit. Will likely contact the manufacturers as one says it is solar panel compatible so there is hope.
15kW PV SE, VI, HM, EN
42kWh LFPO4 storage
7kW ASHP
200ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
WBSx2
Low energy bulbs
Veg patches & fruit trees