Pumps Glycol Pressure And Heat...nasty if it goes wrong



Grundfos Boiler Pump

This the part where you HAVE TO GET IT RIGHT. I used a Grundfos boiler pump to circulate solar heated glycol which has 3 speed settings depending on the flow rate that you choose. The red tank top right is a boiler expansion which will compensate for pressure changes in the 1/2 inch copper pipe as the fluid expands and contracts with heat. Without this tank you could have an explosion due to boiling glycol, nasty stuff....I also installed a second pressure relief valve after the expansion tank, just in case and made certain to face the blow off away from the wife's laundry area. The pump is hooked to a 74 stage timer and kicks the pump on every 45 minutes for 15 minutes during the daylight hours. The green hose of which there are two in the system are to bleed air and to do fluid top ups when required.

Torpedo Casing Heat Exchanger

I used an old Torpedo Casing, (that's another story!) I just happened to have one lying around to house the heat exchanger. After winding two 50 ft lengths of 1/4 inch copper pipe around a 4 inch pipe to form two large spring like coils that ended up being 3ft in length each. After intertwining the two coils I had a first class heat exchanger. In a closed system such as this Glycol travels through one coil and water travels through the other and in a perfect world the heat transfers from one coil to the other.
After a lengthy battle of bending and coiling copper pipe I wrangled the heat exchanger into submission and got it tightly packed with the NASA insulation into the torpedo casing. One end of the casing threads off to get the Torpedo out or in my case to get to the heat exchanger in.


Temperature And Pressure Gages

 After hooking up the distribution lines and filling the system with Glycol, about 4 litres, I turned the pump on and had boiling glycol running through the heat exchanger within minutes. The heat exchanger looses about 10 percent across the board and the rest ends up in my domestic hot water tanks. I installed 2 pressure gauges and 2 temperature gauges to monitor the system. One set upstairs and one down, just to be on the safe side. And one last word pressure relief valves are worth their weight in gold , if all else fails, they don't. Stay tuned for the next component of "The Daltonator" Storage tanks and Wood stoves.