After three months of burning I was wondering if my stack remained clean. The chimney (external double wall 15ft long and then 8 feet on the inside of the house, single wall) was very black on the outside of the hood.
I wasn´t expecting problems because my channel is pretty short.
Up on the roof I only found powdery stuff, so that´s ok. The blackness was the creosote that condensed on the outside, doesnt look pretty but no problem.
So I wasn´t burning to cool.
While I was up there I installed the temperature sensor for a wireless temperature logger. (http://www.arexx.com/templogger/index.htm). The probe has a limited range up to 257F or 125C.
Since creosote shouldn´t condense below 250F I could check if the stovepipe at least got hot enough.
Time to burn!
Within 10 minutes after starting the Oslo with kindling the probe went above 257 (at the top of the chimney that is)! The stovetop was at 200 at that moment.
After the kindling turned to ash (after 20 minutes of flame) it took another 1/2 hour until the chimney cooled enough to be in reach of the measuring device.
So how hot has the chimney been then? I haven´t got a clue.
To solve that puzzle I moved the probe from the inside of the channel to the outside of the inner tube, the temperatures are lower there so I can keep measuring at higher exhaust temps. I made a little tunnel in the insulating material and shoved the probe in.
Next I inserted a PT100 probe in the channel with a measuring device (non wireless) this device measures up to 500F but you have to be there to eyeball the measurements.
I lit the stove again and went up again.
It turned out that when the exhaust gasses reach 250 the probe in the insulation was still way below 200..
This time the measurents stayed below 250 much longer, Still, when burning at 200 stovetop, the temperature is way out of reach of the device in the insulation layer.
I´m going to experiment a little more when burning hardwood in a slow pace but I´m pretty sure there is a lot of heat in my chimney that I might be able to recover in a safe way.
I wasn´t expecting problems because my channel is pretty short.
Up on the roof I only found powdery stuff, so that´s ok. The blackness was the creosote that condensed on the outside, doesnt look pretty but no problem.
So I wasn´t burning to cool.
While I was up there I installed the temperature sensor for a wireless temperature logger. (http://www.arexx.com/templogger/index.htm). The probe has a limited range up to 257F or 125C.
Since creosote shouldn´t condense below 250F I could check if the stovepipe at least got hot enough.
Time to burn!
Within 10 minutes after starting the Oslo with kindling the probe went above 257 (at the top of the chimney that is)! The stovetop was at 200 at that moment.
After the kindling turned to ash (after 20 minutes of flame) it took another 1/2 hour until the chimney cooled enough to be in reach of the measuring device.
So how hot has the chimney been then? I haven´t got a clue.
To solve that puzzle I moved the probe from the inside of the channel to the outside of the inner tube, the temperatures are lower there so I can keep measuring at higher exhaust temps. I made a little tunnel in the insulating material and shoved the probe in.
Next I inserted a PT100 probe in the channel with a measuring device (non wireless) this device measures up to 500F but you have to be there to eyeball the measurements.
I lit the stove again and went up again.
It turned out that when the exhaust gasses reach 250 the probe in the insulation was still way below 200..
This time the measurents stayed below 250 much longer, Still, when burning at 200 stovetop, the temperature is way out of reach of the device in the insulation layer.
I´m going to experiment a little more when burning hardwood in a slow pace but I´m pretty sure there is a lot of heat in my chimney that I might be able to recover in a safe way.
