Well, I haven’t written about this yet because we were waiting to see how the system worked over a prolonged period of time. We’ve had this system working for 2 months now and I have to say we have more hot water than we really need. Most suppliers say that it is really more of a pre-warmer for you water rather than an actual heater system but we get some pretty hot water each sunny day. This system even works during cloudy days.
The saga of the solar DHW system starts at the the Quadra Island Building Supply. The owner brought a couple of the kits in to sell but they came with no instructions and in a whole ton of little bits. They languished at the building supply for many months before Ben and I decided because we were spoiled by all the hot water we had during the winter thanks to our woodstove, we needed a more constant source of hot water during the times we don’t use the woodstove. A conventional heater was out of the question as it would have been too big a drain on our power system (we are on a solar system, independent from the grid). We didn’t want a propane on demand heater because then we would have to have propane delivered which is contrary to our independent living scheme. So we offered to take the kit off the building supply’s hands (of course we paid for it).
A mere 4 days later, (it really did seem much longer) after countless trips to the building supply, a couple of temper tantrums on both our parts, issues with leaks and a broken flow-meter (thank you hose clamps, tar and rubber ) we had a partially limping system on the go. It took a few more weeks to get the glycol loop figured out (how break air-locks, where are all the leaks etc. ) but we are now hot-water independent.
We have evacuated tube collectors which are basically glass tubes that have a copper fin in them that heat up and transfer that heat to glycol that is in a tank above the glass tubes. The hot glycol is pumped down into a copper coil that runs through our hot water tank, transferring its’ heat to the surrounding water (through the tube walls) and is then pumped back up cold to the tank connected to the tubes. The glycol never comes into contact with our water as it is in its’ own separate tube. FuN!
The frame for the glass tubes and attached glycol tank
Our brains of the system. When the sensor at the top of the system reaches more that 8 degrees celcius difference from the sensor at the bottom of our hot water tank the pump switches on. This was just after we started the pump. from 16 C to 43 C in less than 15 minutes.
Yaya for hot water!