Carbon monoxide
Posted: Wed Nov 02, 2022 10:47 am
by tx_swordguy
Hey guys , i have had one of the co cards and noticed it said sunlight can bleach the color dot. Therefore i bought a digital co detector. With the vents open i get zero co within the cabin area. That is at face level, in and around the floor and behind the dash as best as i can get while flying. If i put it behind me in the tail cone at arms reach i get as much as 30 ppm ( mostly 15-20). I have tried putting it along the sides of the seat and wing root area thinking it may be coming from there but nothing . Now if i close the vents and turn my eye ball wind screen vents ( which actually suck inside air out to stop incoming air) the co rises in the cockpit area to 20-30 ppm with the tail cone reaching 50 ppm. I know that 50 ppm is still OSHA 8 hr exposure limit but wonder what others may have found if they had tested in a similar fashion. Not sure where it would be coming in if not the fw or wing root/ spar bay. I have a single fuselage vent under the tail and was wondering if a second one either on the opposite side or on the bottom of the fuselage might be needed. Ideas and advice please.
Re: Carbon monoxide
Posted: Wed Nov 02, 2022 4:42 pm
by Panther16
Likely coming in thru the Circular hole at the base of the vertical tail spar tail post Assembly. Try taping the hole closed with speed tape.
Keith Rhode
Sonex 214KE
Re: Carbon monoxide
Posted: Wed Nov 02, 2022 9:04 pm
by 13brv3
Have you noticed any increase with flaps down? I was fine with the flaps up, but down clearly was pushing exhaust back in through the holes for the flap pushrods. I was seeing numbers in the upper 80’s just from base to the runway, and you could smell it. While researching CO readings, I kept seeing reports that it could be sucked back in around the tail openings, so it sounds like you’re on the right track.
Rusty
Re: Carbon monoxide
Posted: Wed Nov 02, 2022 9:11 pm
by Bryan Cotton
I have a digital monitor on the panel. You can see it in my pics and videos. I have yet to get over 0 ppm.
Re: Carbon monoxide
Posted: Thu Nov 03, 2022 2:25 pm
by tx_swordguy
Thanks guys i will investigate the tail cone. I never got above 0 on the dash either but the closer to the tail cone i got the numbers increased. I will try sealing the tail more
Re: Carbon monoxide
Posted: Thu Nov 03, 2022 4:11 pm
by DCASonex
There are two holes back on the tail cone if you have a conventional tail, the second one on the vertical post for the rudder, My CO2 went to near zero after plugging the two holes.
David A.
Re: Carbon monoxide
Posted: Sat Nov 05, 2022 5:38 pm
by tx_swordguy
I tried plugging the two holes in the tail ( covered with gorilla tape). I then flew with all vents closed trying to get the co as high as possible. In the cabin the highest i saw was 18 ppm with most of the time fluctuations from 0-11. ( it looks like 10 is the lowest above 0 it will read.) sitting on a blanket in the baggage compartment about shoulder level and 2 ft behind my head highest reading was 34 with most in mid twenties. So it did help and cut my readings by 40% ish. I then put it in max reading hold setting and left it in the baggage compartment in the same place checking it every so often with it not getting above 31. I came in and landed with 2/3 flaps like normal and taxied to the fuel pumps. When i reached back to grab the monitor i was shocked that it maxed out at 148! Obviously the flaps cause a huge change in airflow and co infiltration. I think it must be coming in through the wing root since tail holes were taped up. What this taught me is obviously there is a huge difference in co concentration within the cockpit from the dash to the baggage compartment. I have also lost faith in those cheap co cards. I don’t suggest always flying with a high dollar co monitor but a $38 amazon monitor to give you an idea of what and where you have co is a wise investment.
Re: Carbon monoxide
Posted: Sat Nov 05, 2022 5:53 pm
by Bryan Cotton
I have this one. I’m not sure it’s any good.
https://www.amazon.com/gp/aw/d/B08TRKL94H
Any recommendations?
Re: Carbon monoxide
Posted: Sat Nov 05, 2022 6:35 pm
by tx_swordguy
Don’t know if one digital is better than another . The one i bought is a hand held meter that has a yellow face and 4 buttons on it. Retails on amazon for $39. I cant figure out how to link it on my ipad. As long as it will show a reading of some kind it should at least give you an idea of the amount and where it is coming from. I have never had one of the cards go dark and then i saw that sun can bleach it. Also don’t know at what level it turns black. Those two items made me get the digital and started experimenting with where and how much co I actually had.
Re: Carbon monoxide
Posted: Sun Nov 06, 2022 5:12 pm
by 13brv3
I guess I got the high dollar one- https://www.amazon.com/gp/product/B076S6KBP2 I recall reading good reviews of it online, and it works well. My only complaint is that it doesn’t automatically turn off, and it takes 2-3 min to calibrate on power up. During that time, it needs to be in clean air, so I just have to remember to turn it on before pulling the plane out of the hangar. I had a really old one that was long past it’s “quit using after” date, but comparing the two showed that they gave nearly identical readings. I’d never rely on those spot detectors.
Rusty
Re: Carbon monoxide
Posted: Wed Nov 09, 2022 7:29 am
by bipbuilder
All this carbon monoxide talk has convinced me. In the the name of safety, I will pull the trigger and install a smoke system. The carbon monoxide and the smoke come from same point. I may have to use the smoke to check for carbon monoxide infiltration in cockpit quite often, but just in the name of safety.
Re: Carbon monoxide
Posted: Fri Nov 11, 2022 7:23 pm
by Brett
I have been trying to solve this issue on my plane for a while now. I only found out about the CO ingress when I installed the smoke kit.
I bought an electronic CO meter after that and realize they are a good investment. I should have bought one after listening to the Sonex podcast about them in hindsight.
I have taped up the holes in the rear tail post but that seemed to make the readings higher. I have since re opened them. My levels are fine with the cockpit vents open but when closing them CO creaps up to over 30ppm … I find it actually a bit disturbing I can’t seem to solve the issue easily.
I extended my exhaust also and have done a few other bits and bobs but again to no avail.
Re: Carbon monoxide
Posted: Sun Nov 13, 2022 7:12 pm
by Skippydiesel
I use a small digital CO monitor that is designed for use in boat & caravans (travel trailers). From memory it coast about $30 Australian. It is powered by two AA batteries (which seem to last about 2 years). It keeps a running record, so that I can review Max & Min. Has both audio and visual (light) alarm. I haven’t put it in my new, yet to fly, Sonex but in my last aircraft I had it located in the passenger foot well, away from vents/drafts, where it should read the highest levels and I can see it (when I don’t have a passenger). In about 5 years of use it never alarmed and never recorded levels of any concern.
Re: Carbon monoxide
Posted: Sun Nov 13, 2022 9:35 pm
by tx_swordguy
In regards to placing a monitor at foot level . I would at least get a reading at your face level with both the vents open and closed. I found a rather large difference depending on where the reading was taken. A zero reading at your feet doesn’t help much if you are getting 200 ppm at your mouth. If nothing else you will know what reading you get and. Then you can put it at foot level again if you want
Re: Carbon monoxide
Posted: Tue Nov 15, 2022 6:14 pm
by Skippydiesel
CO is denser than air and will collect/concentrate in the low points (foot wells, etc). So the reasons for placing the detector low down is to give the pilot adequate warning of a developing situation.
It is unlikely but possible that air vents could be a rout for CO entry however it is also likly that the CO would be “mixed” with fresh air giving a low reading on the monitor