70% water 30% Glyckol is freezing up here, we must use 50:50 mix
Also what is good when using copper spiral heat exhangers is that I can put it into my current water heater, that is insulated so that it keeps 80 litres of water hot for days without electricity, water that comes to it has pressure of some 3 bar.
THere is also need to went some excess heat out, so for that is needed own circuit with valves and that should have the rad and e-fan.
Princible has much the same, some details are different really.
For easy to do exhaust heat exhanger, one could take y-pipe or two and put larger diameter pipes there using some aluminium flexible tubing, so less problems with welding, or then take straight pipe of enough length and put it into a box filled with water, and pipe outlets.
Polyurethane insulation is what we here use for pipes, inch thick or thicker, boiler itself should reside at warm indoors actually. those heat exhangers feed and return lines need some valves so that when motor is not running they are not cooling the water.
But for heating I of course need lot bigger tank, one that needs to be perhaps thousands of litres in size, I really don't know how big it should be, but to allow it to be loaded so that heating for house there is plenty for 24 hours, water don
t need to be too warm, some 40 degrees should be enough really.
One problem with using electricity for immersion heaters is that motor is already outputting more heat for needed amount of electricity than what heat can be mostly used.
Two big problems, 2000 litre insulated tank is not going to be cheap, and of course enough big generator + batteries will cost a lot too.
But you never know what you may find if keeping eyes open.
Or daisy chain together whatever ones you can get cheap
