I'm sure that I will regret posting this but last weekend on the dive boat we had a debate about temporary scubber storage conditions and heat. A few of my dive buddies have been trained and have gotten in the habit / routine of immediately taking their scrubbers out of their rebreathers and putting them in a drybag / sealed container immediately after diving. Their thoughts are having the scrubber sitting in direct heat inside the rebreather can somehow compromise the scrubber and lead to a CO2 breakthrough. They also cited leaving the scrubber in the unit could cause caking / clumping which they believe could result in channeling and allow a CO2 bypass.
They immediately bag their scrubber to "cool it down" and remove it from the humid / wet enviroment of the rebreather. I am a bit skeptical of this since I dont think it's an issue with a properly packed scrubber. I dont think there are any issues with immediately removing the scrubber from the unit post-dive but I question the science behind it.
They said they just feel better / safer if they immediately take their scrubbers out of their units and remove it from the moisure / humid environment inside the rebreather. I'd rather go by science than feelings.
Me personally - I see no real value in doing this immediately but I'm willing to be educated if I'm somehow doing something adverse to my scrubber. I do not like opening a rebreather on a dive boat and prefer to do this when I get home. I dont see how leaving the scrubber in the rebreather for ~8 hours is going to cause issues but the conversation focused on having the rebreather sitting in direct sunlight effectively baking in the back of the boat and then sitting the bed in a pickup truck on the drive home. Let's say for sake of argument 90-100f (37c) degree heat wave / sitting in direct sunlight. I realize this is basically every summer day in Florida.
My opinion is provided the scrubber is not flooded and the rebreather is not compromised there is no more CO2 flowing through the scrubber material and the reaction should be minimal. Furthermore we all know heat makes the reaction more efficient but I'd like to understand if there is a mechanism here that would damage the CO2 absorbant. The rebreather is essentially a closed / sealed system at this point albeit with a good amount of moisture and heat inside when sitting in direct sunlight.
To be clear - I am not talking about long term storage. I'm talking about doing subsequent dives the next day or a few days later.
Scenario: You pack a fresh scrubber on Friday night and do a dive on Saturday morning to 160ft (48m) for a 90 minute total runtime. Cold water (mid 40s to low 50s/8c) but no major current or high levels of exertion. It's a particularly really hot (90-100f) degree day and the rebreather is sitting in the back of the boat for 8 hours followed by a 2 hour drive home in the back of a pickup. You have another dive scheduled for the next morning.
In the above scenario the person took a CO2 hit 5 minutes into their dive the next morning. They believe the reason was because they left their scrubber inside the rebreather. This scenario happened many years ago and was not recent nevertheless it changed the way they handle their scrubber. Now I realize there are hundreds of other variables that could have caused this and it's really hard to definitely know the root cause. Anything from a mushroom valve to scrubber channeling from bouncing around in the back of a boat or pickup truck, high workload, etc.
I called b*llshit on leaving the scrubber in the unit causing this I'm happy to be educated here if I'm somehow cooking my scrubber by leaving it inside the unit on particularly hot summer days. For me I have no qualms about leaving the scrubber in the rebreather if I am diving the next day however I usually open everything up when I get home, dry outside the inside of my canister with paper towels, dry my cells and rinse counterlungs. I then seal everything up for the next day and re-do my rebreather checks. This has worked for me for many years and hours of rebreather diving without issues.
I have read the paper on "Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters" but this isnt really applicable
pubmed.ncbi.nlm.nih.gov
Is there any actual science or studies behind temporary scrubber storage inside a rebreather and high heat (100f/38c+)? I'm looking to have a friendly conversation and not, "My rebreather instructor told me this and you're going to die."
They immediately bag their scrubber to "cool it down" and remove it from the humid / wet enviroment of the rebreather. I am a bit skeptical of this since I dont think it's an issue with a properly packed scrubber. I dont think there are any issues with immediately removing the scrubber from the unit post-dive but I question the science behind it.
They said they just feel better / safer if they immediately take their scrubbers out of their units and remove it from the moisure / humid environment inside the rebreather. I'd rather go by science than feelings.
Me personally - I see no real value in doing this immediately but I'm willing to be educated if I'm somehow doing something adverse to my scrubber. I do not like opening a rebreather on a dive boat and prefer to do this when I get home. I dont see how leaving the scrubber in the rebreather for ~8 hours is going to cause issues but the conversation focused on having the rebreather sitting in direct sunlight effectively baking in the back of the boat and then sitting the bed in a pickup truck on the drive home. Let's say for sake of argument 90-100f (37c) degree heat wave / sitting in direct sunlight. I realize this is basically every summer day in Florida.
My opinion is provided the scrubber is not flooded and the rebreather is not compromised there is no more CO2 flowing through the scrubber material and the reaction should be minimal. Furthermore we all know heat makes the reaction more efficient but I'd like to understand if there is a mechanism here that would damage the CO2 absorbant. The rebreather is essentially a closed / sealed system at this point albeit with a good amount of moisture and heat inside when sitting in direct sunlight.
To be clear - I am not talking about long term storage. I'm talking about doing subsequent dives the next day or a few days later.
Scenario: You pack a fresh scrubber on Friday night and do a dive on Saturday morning to 160ft (48m) for a 90 minute total runtime. Cold water (mid 40s to low 50s/8c) but no major current or high levels of exertion. It's a particularly really hot (90-100f) degree day and the rebreather is sitting in the back of the boat for 8 hours followed by a 2 hour drive home in the back of a pickup. You have another dive scheduled for the next morning.
In the above scenario the person took a CO2 hit 5 minutes into their dive the next morning. They believe the reason was because they left their scrubber inside the rebreather. This scenario happened many years ago and was not recent nevertheless it changed the way they handle their scrubber. Now I realize there are hundreds of other variables that could have caused this and it's really hard to definitely know the root cause. Anything from a mushroom valve to scrubber channeling from bouncing around in the back of a boat or pickup truck, high workload, etc.
I called b*llshit on leaving the scrubber in the unit causing this I'm happy to be educated here if I'm somehow cooking my scrubber by leaving it inside the unit on particularly hot summer days. For me I have no qualms about leaving the scrubber in the rebreather if I am diving the next day however I usually open everything up when I get home, dry outside the inside of my canister with paper towels, dry my cells and rinse counterlungs. I then seal everything up for the next day and re-do my rebreather checks. This has worked for me for many years and hours of rebreather diving without issues.
I have read the paper on "Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters" but this isnt really applicable
Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters - PubMed
Rebreather divers should consider placing partially used soda lime scrubber canisters in vacuum-sealed plastic bags if storing them for longer periods than overnight. If a partially used scrubber canister is to be used again the next day then the storage modality is unlikely to influence...
pubmed.ncbi.nlm.nih.gov
Is there any actual science or studies behind temporary scrubber storage inside a rebreather and high heat (100f/38c+)? I'm looking to have a friendly conversation and not, "My rebreather instructor told me this and you're going to die."
