DIY Hydronic system first run, good stuff
Making progress of my DIY hydronic system and was able to run a test on Sunday and will first post what worked!
I filled it slowly with water today from a low point and it has 20 gallons of storage and topped out somewhere around 23 gallons which seems right.
Absolutely none of the PEX connections that I put together using the expansion tool leaked!!!
https://www.crystalpoint.com/cpdownl...stallation.jpg
Fired up my diesel heater and observed the following behavior:
1. It sat there for a bit of time while I think it did its startup sequence of warming up the glow plug, testing water flow and fan speed.
2. It started clicking the pump loudly which muted down as the pump filled with fuel.
3. Exhaust pipe output a little bit of white diesel smoke.
4. Internal fan speed ramped up and the exhaust started to roar and the output fluid pipe was about 170 degrees (no muffler at this time).
5. When turned off it went through a shutdown and cool down cycle for about 3-5 minutes before fully shutting down.
So I believe that the diesel boiler is functional.
First run of DIY hydronic system, not so good stuff
1. Some of the manual connections that i made had slow drips during the water testing phase.
2. The air purge valve didn't seem to work at all, might have had it adjusted wrong.
3. I think there was problems with the check valves that I used in my design, maybe not enough flow rate to fully close.
4. The diesel heater cycled up and down in heat output which might be:
a. Maybe it was programmed with non-standard settings because it was used warm a generator in an arctic settings and hey if the cold coolant is 80 degrees, job is done. I do have a diagnostic kit that I have to figure out how to use with this heater.
b. Check valve was more and likely not fully closing and allowing re-circulation between the input and output to the diesel heater. Maybe I should do a standalone test with a tank of water. Dang, I gave away a rain barrel last month that I could have used for this...
c. Replace check valve for diesel heater with a automatically closing valve as soon as the heater is commanded to start; forcing all flow to pass through the remote diesel boiler.
5. Circulation/stir pump seems to keep loosing prime as I mounted it too high up.
Anyway I was able to bring the storage up to about 110 degrees though the target was 160 degrees, but hey it was a first run!!!
DIY Hydronic system automation controller
The last day and half have been a big wiring project for the DIY hydronic heating system that I have been working on.
Anyway, here’s the layout that I came up with, bit more of a rat’s nest then I originally planned, but hey working on getting it wrapped up and done!!!
https://www.crystalpoint.com/cpdownl...Controller.jpg
Also, I am running out of bay wall space. So, I pre-wired everything up on a one-foot square board with extra-long wiring leads and mounted it to the ceiling of the plumbing/electrical bay.
Your basic Raspberry Pi driving two eight channel relay boards. I went with a left over SSD drive for long term reliability; as the typical SDCard can wear out in 2-3 years or sooner depending on the write cycle frequency. Plus the SSD drive is faster...
The functions that it is currently controlling is:
- Bedroom heater zone pump.
- Bathroom heater zone pump.
- Kitchen heater zone pump.
- Living room heater zone pump.
- Front bays freeze protection pump.
- Rear bays freeze protection pump.
- Stir/circulation pump.
- Pump for Engine preheating and thermosiphon heat recovery.
- Pump for Generator preheating and thermosiphon heat recovery.
- Diesel Boiler remote on/off.
- Electric ball valve to force flow through the diesel boiler when it is on, bypass when off.
- Temperature sensor for hydronic tank output.
- Temperature sensor for Engine coolant, thermosiphon heat recovery monitoring.
- Temperature sensor for generator coolant, thermosiphon heat recovery monitoring.
I still have four relays left over and could add another eight-channel relay board for $10.00 before I max out the Raspberry Pi. All told this could be duplicated for around $120.00
Once all the hardware is installed then it’s software time!!! Something I do everyday in my day job.
Starting with a simple manual over-ride web page with simple touch buttons for each relay function.
Software wise in the long term will be smart scheduling and Alexa voice control integration. Which is easy to do with Internet of Things Node Red software.