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Venting CO2 (dry ice)

A

abuura

Well Known Member
I'd like to be able to carry a couple days' worth of fresh food on my summer Virginia to Oregon trips and ice in a cooler melts too quickly. If I were to use dry ice, I'd be concerned about CO2 accumulating in the cabin. The two air vents' breeze is evacuated out the gaps in the slider canopy and aft of the luggage compartment, but it would likely be safer to send it more directly overboard.
If I were to plumb a hose through the luggage compartment cover, would there be enough air movement to evacuate the CO2 out the openings in the empennage? Does anyone have experience making this or other options work?
Thanks all.
 
Venting needed ??

This may apply or may not. There have been many RV-10 builders who have installed non-vented EarthX batteries aft and after crunching air flow data along with Earth X assistance determined that the air flow in at least a 10 was more than enough to offset the type of thermal issue from their batteries. It seems CO2 emissions would be a fraction of that of an overheated lithium battery. Also, I believe dry ice is allowed in the baggage compartment of commercial airlines. Again, no data to prove if this is ok. NACA vents (If open) do pass a significant amount of air.
 
Dry ice in a cooler will produce pressure as it turns back into a gas. You could drill a hole in the top corner of the lid (that you could plug later) and insert a 5/16" I.D. clear hose from ACE hardware, and pass about 12" through the cargo bulkhead corrugation and just let it hang there.

Dry ice is about -100 deg. F. It is best used to keep things frozen. 5 lbs should easily last a full day and up to 24 hours. Test it first at home. You should also be careful to protect the floor of the ice chest...... -100 may just crack it.

Co2 is heavier than air. So if there is any in the cabin, it will drop to the floor and flow out with the exhausting air.
 
I did it for SNF this year (non RV)

A buddy and I went to SNF this year without our RV's, settling for his Seneca 5 with A/C and lots of room to haul goodies back in. We had a large hard cooler in back with lots of hydration products and used the dry ice bags from the grocery store (much lower volume than H2O ice). It really performed better than I expected, and lasted about 3 days..no CO2 alarms from the indicators, and I doubt there is much off gassing with a good cooler anyway. My buddy is a corporate pilot and often used the dry ice in their missions.
 
dmattmul said:
This may apply or may not. There have been many RV-10 builders who have installed non-vented EarthX batteries aft and after crunching air flow data along with Earth X assistance determined that the air flow in at least a 10 was more than enough to offset the type of thermal issue from their batteries. It seems CO2 emissions would be a fraction of that of an overheated lithium battery. Also, I believe dry ice is allowed in the baggage compartment of commercial airlines. Again, no data to prove if this is ok. NACA vents (If open) do pass a significant amount of air.
Click to expand...

Dry ice is indeed allowed in 121 aircraft/ops, but with some total amount limitations (which I don't recall).
The CO2 would be continuously vented and the plumbing featured by a couple people who've installed their battery behind the bag compartment would likely work fine.
 
abuura said:
Dry ice is indeed allowed in 121 aircraft/ops, but with some total amount limitations (which I don't recall).
The CO2 would be continuously vented and the plumbing featured by a couple people who've installed their battery behind the bag compartment would likely work fine.
Click to expand...

There's limitations, but you can have literal tons onboard.
 
gasman said:
Dry ice in a cooler will produce pressure as it turns back into a gas. You could drill a hole in the top corner of the lid (that you could plug later) and insert a 5/16" I.D. clear hose from ACE hardware, and pass about 12" through the cargo bulkhead corrugation and just let it hang there.
Click to expand...

There's no need for that. Coolers are not sealed units. Even something like a yeti with those rubber straps cannot seal a cooler to cause pressure buildup to the point it would be an issue. The pressure will leak far before it gets to much of anything.
 
abuura said:
If I were to plumb a hose through the luggage compartment cover, would there be enough air movement to evacuate the CO2 out the openings in the empennage? Does anyone have experience making this or other options work?
Thanks all.
Click to expand...

I can't speak to what happens with the cabin vents open (i.e. where the air goes), as have not observed or researched, but do know that with the vents closed, air flows FROM the emp area into the cabin and is pulled out of the fuselage and canopy leakage areas by the low pressure that exists on the outside of the fuse/canopy.
 
CO2 from sublimating dry ice will (or at least should) not show on a CO monitor.

I think you'd have to work HARD to asphyxiate yourself in an RV cockpit with dry ice of any quantity.
 
Reference point: the typical human exhales 2 lbs of CO2 every 24 hours. So if you have 2 pounds of dry ice in your cooler, and it lasts for 24 hours, it’s about the same as having another passenger on board. Anyone here ever worry about excess CO2 accumulating from passengers?
 
BobTurner said:
Reference point: the typical human exhales 2 lbs of CO2 every 24 hours. So if you have 2 pounds of dry ice in your cooler, and it lasts for 24 hours, it’s about the same as having another passenger on board. Anyone here ever worry about excess CO2 accumulating from passengers?
Click to expand...

Other gasses, but not CO2..
 
lr172 said:
air flows FROM the emp area into the cabin and is pulled out of the fuselage and canopy leakage areas by the low pressure that exists on the outside of the fuse/canopy.
Click to expand...

100% correct for a 7.

You are right to be concerned about this issue, but only testing will answer your question. All RV's are sealed differently. You need to test for the worst case - you hit turbulance, and the cooler spills open. Put 5 lbs in your plane on a hot day and use an O2 meter to measure the levels throughtout the flight phases. Our Cabins breath differently in climb, cruse, and decent. try it with vents open and closed.

I have used Dry ice to purge the oxygen from tanks of flamable contents so we can safely weld on them. I have seen a worker become incapasitated while doing the welding. - this is after putting 20 lbs in a tank 50X the volume of an RV.
An RV should breath way better than a static tank, but it is still worth being concerned over and getting a real answer.
 
I would be somewhat concerned about dry ice in a small volume aircraft like a RV. Airliners can carry large amounts in the cargo holds. (220lbs for most narrow body aircraft) The air exchange rate is however very rapid and flows from the cabin to the cargo holds and overboard. Live animals are not permitted in any cargo compartment with any dry ice. Crew members on widebodies are not permitted to use lower deck crew rest facilities if any dry ice is loaded in that cargo compartment. The rate that dry ice can displace oxygen is temperature as well as quantity dependent.
I suspect our aircraft are so leaky it’s probably a non issue but wonder about higher altitude flights with the air vents closed.
 
..no CO2 alarms from the indicators, and I doubt there is much off gassing with a good cooler anyway. My buddy is a corporate pilot and often used the dry ice in their missions.[/QUOTE]

Does a carbon monoxided (CO) detect carbon dioxide? CO2

Just asking, never thought about it...
 
CO2 isn't the problem as much as cockpit visibility. My friend flies for a Fedex contractor. A couple years ago flying hew flew an overnight short run in a Caravan. Beautiful VFR night when he had smoke in the cockpit. Not knowing what it was he donned his mask and declared an emergency. There was no visibility out the windscreen or side windows so he basically flew a zero zero instrument approach to land. It turned out to be dry ice that fogged up the cabin. Wish I still had the LiveATC recording.
 
Dry ice

I flew C-130s for a long time. The C130E could carry 660 lbs of dry ice due to its air exchange rate. Any malfunction of our air conditioning system would result in the cancellation of the cargo haul. We have a 25 ltr oxygen system in case the system has a malfunction. I believe you would be taking an unnecessary risk. 2 more cents to add to your thought process.
 
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