… or ‘how to spend a winter holiday to turn ubuntu into a heating control system’
about two years ago we got a huge solar thermal heating system for our house which worked fine for the first summer … until it overheated … we sadly had fallen out with the heating contractor since he screwed up a lot of unrelated stuff in the house making us very unhappy and we got never around to find a new guy for it (beside that i wanted to learn to handle all of the system myself)
so after two winters where we rather heated the house with wood in the fireplace and the heating only worked at half power, this year i had to burn all my vacation days that stacked up over the year in december havin nearly a full month of holidays … alongside we had one week where it really got cold and i really didnt feel like chopping wood again :)
so i decided to put up my scottish accent and spend as much time as needed with the three 1000 liter tanks and their pipes and valves in the engine room until i get that damned thing to fly at warp 10 :)
after a week of fiddling and studying i finally found out that the guy had wired up half of the system wrongly, valves that the control system triggered to open were closing instead, water flowed through pipes it wasnt supposed to, heat got routed into places where it wasnt stored etc …
so after two days of rewiring i suddenly had the heaters warm and cosy in the rooms, while the heating boiler wasnt running 24/7 anymore but only when heating up was needed and properly stored its heat in the big tanks, yay !!
the control unit is mounted in the worst place one can imagine in the basement room. you cant easily reach or see it. to see a sensor or valve value you have a little wheel you need to scroll up and down. you can only see about three values at a time on the display and indeed it’s usually three unrelated ones. so i spent my days scrolling this darn wheel up and down most of the time, standing on one leg in a very inconveninent position …
after i had the system back to normal and had a warm office again i started googling a bit and i found there is a usb datalogging unit for that box and the bill for teh system suggested that i even own it !
i found the little box after searching a day for it in another room in the basement hidden behind some pipes (no idea why the heating engineer had put it there or why he didnt bother to tell me it exists) … funnily it didnt work at all … guess what, the two cables running into it were indeed flipped …
after fixing that i actually got some data packets on my laptops USB port, yay !
googling even more i finally found that someone called Holger Römer had written some linux software to properly recieve data from it and he uses it on debian and ubuntu !
(i’m about to package it but there are some issues like missing license files etc in the source tree before i can do it)
i spent another day to write a little script that generates html from the data in 5 second intervals, worked out an hydraulic plan in inkscape that i put in the back of that data and installed all that on a spare computer i had lying around with a minimal ubuntu and lighttpd.
since i travel a lot and for the fun of it, i also wrote an rsync script that syncs the sensor and valve status data to a public place in longer intervals, so i can actually check the system while travelling the world (just click the picture above and you can actually see the current data)
so that was my little holiday adventure i wanted to share. if you have a similar system and are intrested in getting the script or the inkscape file to create your own hydraulic plan, feel free to contact me. i’m happy to share and i actually plan to move forward with that stuff up to a point where i can have proper mrtg graphs that you can combine to optimize the system, a desktop tool to do all that from your local machine and indeed i want to turn the website into an interactive webapp i will put on a touchscreen next to the heating so you can actually steer the system through it, but that will be work for another holiday season.
what really amazes me is that all this is possible with ubuntu and its open source tools. my little adventure wouldnt have been possible without all the work you guys do every day on the distro and on the thousands of open source projects. thanks so much to everyone whose software helped me to make that little project become reality …
or to say it in ubuntu: ‘I am warm as I am because of who you all are’ ;)