This is an old thread going back a surprising number of years. How time flies,? The top pic shows a 210ltr Atherm thermal store. The silver top of our DC 138v immersion heater can be seen in the centre of the top of the tank with the heavily insulated DC cable coming down from the right.
The whole idea was simples from word go. There was a rad located under the stairs. The rad was removed and the flow pipe was sent verticle through the pump up into the top of the store coil . A bypass pipe was fitted with a 22mm flap valve to prevent cycling and of course the pumped water exites through the bottom coil pipe and off towards the boiler and rads. So When the winter sets in, The Thermal store acts just like a Rad with the stove dropping heat into it when I open the original manual operated rad stat.
The original set up was controlled by a mecanical stat with the hollow pipe and sensor down inside the sheav next to the DC immersion. The thin hollow pipe led back to a rotary switch which contained the relay. The relay had grown lazy with age (perhaps) and failed to trigger the pump in early April, ( Not March this time). The hall became like a sauna. I knew there was something badly wrong and a quick inspection revealed that the pump was not working and that i could not reach the screw in the centre of the pump to turn the shaft becasue I did not leave enough room to get at it, me bad.
So off with all the cladding and insulation and a tiny tap on the rotary switch brough the pump to life,, most times,
. First I ordered 2 earlybirds. The reviews were good enough. We got one but the other was not delivered. We are still trying to sort that one out. Then we ordered the fancy one in the second pic. It seems to be very good, in fact very vert good.
It has a host of jazzy goodies and can be programmed to almost walk the dog,,almost is an important word.
I set the temperature to 65.1 and the pump kicks in at 65.6. The gap between can range from 8 to 12 minutes. Depending how far down the sheath inside the tank, I push the sensor and the setting on the pump. The DC immersion is 700mm deep and the sheath a similar depth but running 100mm parallel. The deeper the sensor the longer it takes to trigger the pump but the hotter the water at the top becomes. H,mmm Yee all got that.?
This stat has a bunch of unsightly cables but i will be able to hide most when the testing is complete. It is well made but not for kicking around the floor. The instruction were designed for people who carry large powerful magnifying glasses, tied on a string around their neck, I figured them out over a cuppa and a scone.
I was looking for a stat that could tell me what was happening inside the thermal store without going near it and it,s figures are clearly visible across the hall. It flashes a red light if it senses no load or the temperature creeps too high. It catches your eye quickly. This is good.
The house has two such systems,two 2kw x 138vdc immersions. The one upstairs, the DHWT is programmed to activate the C/H pump when the complete 1800mm high tank has been fully heated,
again dumping the excess heat into the stove and rads. Our 138volt DC charger also uses the immersions to keep it stable to 148vdc.
IN my earlier posts on this thread, I wrote about windturbines heating water directly without batteries. We had a water heating turbine company operating locally and they sold turbines with tanks and 3 immersions at different levels on their tanks No batteries . Donegal, Uses a 2kw Turbine to heat his GSHP Tank with 4 small batteries to stabalise the voltage..It works perfect. Ag Does not use batteries. I use 60 Forkhandles cells.
Im off out to play in the sun,
Biff
I forgot to mention that the fluid that the immersion heats in the Atherm 210 thermal store is totally isolated and has it's own 9ltr header tank directly above the store.
So the Immersions directly heats this water which heated the Coils that contain the Central heating mix.. a slightly back to front solution.
