I went out on a customer issue the other day, I had to meet a locksmith at a customer’s house. After the job was done the locksmith who I have done business with for years and is a friend came back to the shop for a check and a beer. Naturally I showed him my home built boiler. He rent’s so he wasn’t particularly interested but mentioned he buys a 5 gallon can of off road diesel to bring home to heat his house every day. The price is about $3.77 per gallon which is about what the local oil company would charge to deliver. So if it’s the same price why not have it delivered? Because he doesn’t want to, or can’t tie up the $471.25 the fuel company would want for a minimum sale. That amount of fuel would last him about 25 days at his 5 gallon a day rate, maybe less time if the 10 gallon nights are accounted in as well. Since it was quite cold he was planning on buying two cans that night. He said the normal 5 gallons cost him $19/day. Rounding this to $20 for ease of math and multiplying by 30 days per month this is approx. $600 per month for fuel oil. We bought our third ton of of pellets for the heating season for $209 at Tractor supply last week. So our total fuel costs for the year are approx. $800 from November to mid February. What a difference! Not to mention I can’t imagine going to the gas station every day for fuel. What a pain. Having diesel trucks and fueling up at the same pumps I see many different people filling five gallon cans every time I fuel my trucks. I’m not the best at budgeting in the world, but I realize my blessings when I witness first hand how the paycheck to paycheck underemployed crowd deals with winter.
I’ve started calculating the Heating degree days with the Arduino program. It’s a pretty accurate look at the day’s heating requirements. I want to correlate those temperatures to fuel usage. I also have updated the CNC plasma cutter to the 5 start lead screw. Before I made the upgrades I needed to limit the cutter to a linear travel rate of 13 inches per minute to avoid vibration issues. After reassembly I tested the machine to 40 inches per minute with no problems. It may be even better than that I just got so giddy I quit testing. I am hoping this will significantly reduce the slag produced by the plasma cut. Not much motivation to take anything apart at this point. It’s just too damn cold out. It was -5°F this morning here, the HDD days yesterday was 65.5. Stay warm out there. I could back the tractor out of the shop and do some woodworking, maybe build the chip dryer…..
It may not be cabin fever, more just a general malaise. That midwinter everything is working and I don’t want to take it apart feeling. But I have several projects half done at this point. I am waiting for headers to install the Ethernet card so the Ethernet update project is on hold. The CNC plasma cutter is apart awaiting a new lead screw for the y-axis. This is to remove the vibration issues I have been experiencing. I am changing from a single start to a five start lead screw. I will lose one fifth of the resolution I have presently but that will still be plenty of resolution for this application. But the big news is I am finally going to move on building a new firebox. It’s time to retire the over the road fuel tank turned boiler. Well maybe not retire, just move onto a new home. Anyone want to buy this working boiler? I would consider selling the auger and burner feed as well as a combination. The unit is located in Newport, NH if you would like to see it working. It won’t be available until it’s replacement is built. It is after all heating the house, shop and hot water. But I am hoping to have the replacement built before the end of the heating season for some testing. If you are interested drop me an email at: email@example.com
A quick reminder of what the combination looks like, this has successfully burned pellets, chips and to a limited degree sawdust. Ideally you would be a person who can tinker as this is a prototype unit.
The software, Arduino and LCD display all very solid and work very well.
By adding Ethernet capability I can write the data I am currently collecting on the micro SD card to a browser directly. This means I could pull up Firefox and go to my Arduino’s IP Address and see the data. This will give me the ability to read the data from anywhere on my home network as well as anywhere I can get internet connectivity, potentially allowing me to review data from a smart phone remotely. Additionally I could control relays from a remote location as well. But for now the ability to ease the data collection and monitor the process remotely will be a great first step. First I have to buy an Ethernet shield. For those of you not familiar with Arduino this means an additional plug-in board that will stack on top of the Arduino pins.
Here’s a picture of just the Ethernet shield, the connection point you see on the front is the plug-in point for the Ethernet connection. This is a RJ-45 connector. I was able to get a 100 foot Cat 5 with installed RJ-45 connectors for $27 at Home Depot.
At present I have already have a prototype shield plugged into my Arduino Uno. This allows me to easily disconnect and update the Uno without disturbing any wiring connections. There are quite a few wiring connections for the RTC or Real Time Clock, the LCD display, the outside temperature thermister, the boiler water tank thermister, the Auger Feed pipe thermister as well as Relays to turn on the Auger motor and boiler tank water circulator. But when I attempted to plug in a prototype shield into the Ethernet shield there was interference with the RJ-45 connection point. The prototype shield would have grounded itself on the metal so I have ordered Stacking headers to extend the height above the shield. More when the headers arrive.
After writing a similar post on 1/15/2012 I find myself saying basically the same thing, after a -10F night the boiler has kept up. Additionally except for a 12 hour period when I made some boiler modifications the boiler has run continuously for 14 days. There are several differences however. The software is 100% better and controlling the temperature to within a few degrees. The burner is now a waterfall type burner that is much safer and runs more consistently. The hopper and auger setup is much more consistent and dependable as a worm and worm gear than the chain and sprocket setup from last year. Most significantly the burner has proved it can run on chips as well as pellets. During these colder nights it is more difficult for the burner to keep up with chips because of the density differences. The chips are much less dense and because of this the auger must feed significantly more of them. The auger motor may need to be changed to accommodate this burning however during weather that does not require so much energy the chips will burn just fine. I could have easily burned chips for most of December with no issues if they had been dry enough. Which brings me to my second topic.
A test plan. I have taken the Holidays off but it is now the new year and time to make some constant progress. To facilitate the test plan I want to make some incremental improvements in the software. The first change in the software is to gather more data to make better decisions. To do this I am going to first add the date and outside temperature readings to both the LCD display and the data collected. By knowing these I can correlate the feed times to temperature and see how close a relationship between them exists. Next I would like to total the run time of the auger per minute and correlate that to both outside temperature and fuel usage. Armed with this additional data I can then make various burner modifications and see the differences if any graphically. The data is good now but could be better. As you can see from the data below the software is not working properly now. The derivative portion of the formula is not contributing at all. This needs to be fixed in the software.