- Jul 3, 2008
- 71
- 11
Hi all,
I've been using my 160 gallon RF for a few years now. It was sized according to Feldon's, but generously so that every major measurement was made 1.5x what the calculator said. I also added upper air inlets later on.
Here are the stats:
Cook chamber size: around 5.5 feet x 24.4" (straight section without accounting for the curved end) a little bit thicker than 1/8"
Tank CC volume: 163.3 gallons
Firebox side %: 108% (23" x 25" x 24") 5/16" thick
Throat area: 140 square inches
Area under RF plate: 140 square inches
BP gap: Slightly larger than 140 square inches (not by design)
Stack size 5" pipe, 30" inches above CC
Air inlets: waaaaay oversized, running them most of the time around 70% closed.
I think everything should be close enough to not cause any problems... But:
I seem to be having a problem that nobody has, the other end of the smoker where smoke enters the CC is almost 100F hotter than the FB end! The only time both ends are even, is when my wood has just burned down and the heat from the smoke has gone, but there is still residual heat on the BP. I also did try to reduce the hotspot on the upper shelf by welding on a plate in to block the airflow to top shelf (check out the pic). It worked, but it just shifted the hotspot lower. I guess I should remove this plate, since it doesn't do me any good.
Temps have been mapped by Thermowork probes, there's a clear gradient of hot - cooler - cool from CC to FB sideways. Could this be because of not enough draft? Air moving so slowly it has time to cool down too much when it reaches the FB end?
I have three grates and four slides in there, so the slides potentially might restrict the airflow a bit.
My fire burns well, clean and splits ignite nicely. Only problem with my fire is that I seem to be losing my coal bed, but I've kept it going by adding lump and still get the same hot spot. I actually get the same temp gradient with using just lump without any wood. Food generally tastes fine out of the pit.
My doors leak a bit, but I've ran the cooker for around 6 hours empty with both doors 100% leakproofed with foil tape and it made no difference. Also, the upper air inlets did nothing.
I have to add, adjusting the nose of the cooker up or down doesn't seem to have any effect on temps, at least within reason.
Any suggestions? I'm very close to giving up on this smoker, since I can't wrap my head around what's causing this much temp variation...
I've added some pics also to give a better idea of the smoker construction
Slides and the baffle on top shelf (BP to CC opening end):
.
Slides (middle):
Early construction, showing bottom intake pie vent (there are two more at the door, one slightly higher than the fire grate and the upper air inlet way higher):
I've been using my 160 gallon RF for a few years now. It was sized according to Feldon's, but generously so that every major measurement was made 1.5x what the calculator said. I also added upper air inlets later on.
Here are the stats:
Cook chamber size: around 5.5 feet x 24.4" (straight section without accounting for the curved end) a little bit thicker than 1/8"
Tank CC volume: 163.3 gallons
Firebox side %: 108% (23" x 25" x 24") 5/16" thick
Throat area: 140 square inches
Area under RF plate: 140 square inches
BP gap: Slightly larger than 140 square inches (not by design)
Stack size 5" pipe, 30" inches above CC
Air inlets: waaaaay oversized, running them most of the time around 70% closed.
I think everything should be close enough to not cause any problems... But:
I seem to be having a problem that nobody has, the other end of the smoker where smoke enters the CC is almost 100F hotter than the FB end! The only time both ends are even, is when my wood has just burned down and the heat from the smoke has gone, but there is still residual heat on the BP. I also did try to reduce the hotspot on the upper shelf by welding on a plate in to block the airflow to top shelf (check out the pic). It worked, but it just shifted the hotspot lower. I guess I should remove this plate, since it doesn't do me any good.
Temps have been mapped by Thermowork probes, there's a clear gradient of hot - cooler - cool from CC to FB sideways. Could this be because of not enough draft? Air moving so slowly it has time to cool down too much when it reaches the FB end?
I have three grates and four slides in there, so the slides potentially might restrict the airflow a bit.
My fire burns well, clean and splits ignite nicely. Only problem with my fire is that I seem to be losing my coal bed, but I've kept it going by adding lump and still get the same hot spot. I actually get the same temp gradient with using just lump without any wood. Food generally tastes fine out of the pit.
My doors leak a bit, but I've ran the cooker for around 6 hours empty with both doors 100% leakproofed with foil tape and it made no difference. Also, the upper air inlets did nothing.
I have to add, adjusting the nose of the cooker up or down doesn't seem to have any effect on temps, at least within reason.
Any suggestions? I'm very close to giving up on this smoker, since I can't wrap my head around what's causing this much temp variation...
I've added some pics also to give a better idea of the smoker construction
Slides and the baffle on top shelf (BP to CC opening end):
.
Slides (middle):
Early construction, showing bottom intake pie vent (there are two more at the door, one slightly higher than the fire grate and the upper air inlet way higher):