CO2 buildup in full face masks on rebreathers?

[RedSeaDiver2]

Yes - horrible…. Do you know if the skirt is avaiable as a spare part, so you could change it yourself?

Thanks

I would imagine that it is available as a spare part - but whether it fits onto the old mask I have no idea - it might be best to drop an email to Kirby Morgan about that.

 

[RedSeaDiver2]

Rather than starting a new thread I will ask this here as it is related.

We (Martin@Tecme in Germany and myself) are doing a conversion/making an adaptor to enable us to use the previous version of the Ocean Reef mask (photo below) - as I need comms for an archaeology project. As is normal with any rebreather on a full face mask the "mouthpiece tube" will need to be longer than is on the original BOV - in this case a Divesoft Liberty BOV. At this stage we are still designing it (with the aim to make it as short as possible), and I was wondering - how long is too long? And what effect on the WOB and CO2 would extending the "mouthpiece tube" by say 2 inches/50mm have? Anyone have any thoughts? @Dr Simon Mitchell do you have any insight or data?

If we can get this modification/adaptor up and running then it will be available for others to buy through Martin - it will be a P-Port adaptor so will fit a wide variety of BOV's. The Ocean Reef mask will be a good addition to the range of masks for rebreathers as it has a fantastic field of view, is extremely comfortable, comes in two sizes instead of "one size fits a fair few people" like most FFM's, and comms are readily available for it. Obviously the Ocean Reef second stage you can see in the pictures will be replaced by the P-Port adaptor.

 

[Dr Simon Mitchell]

Rather than starting a new thread I will ask this here as it is related.

We (Martin@Tecme in Germany and myself) are doing a conversion/making an adaptor to enable us to use the previous version of the Ocean Reef mask (photo below) - as I need comms for an archaeology project. As is normal with any rebreather on a full face mask the "mouthpiece tube" will need to be longer than is on the original BOV - in this case a Divesoft Liberty BOV. At this stage we are still designing it (with the aim to make it as short as possible), and I was wondering - how long is too long? And what effect on the WOB and CO2 would extending the "mouthpiece tube" by say 2 inches/50mm have? Anyone have any thoughts? @Dr Simon Mitchell do you have any insight or data?

If we can get this modification/adaptor up and running then it will be available for others to buy through Martin - it will be a P-Port adaptor so will fit a wide variety of BOV's. The Ocean Reef mask will be a good addition to the range of masks for rebreathers as it has a fantastic field of view, is extremely comfortable, comes in two sizes instead of "one size fits a fair few people" like most FFM's, and comms are readily available for it. Obviously the Ocean Reef second stage you can see in the pictures will be replaced by the P-Port adaptor.
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Sorry about the late reply. I suspect that a small extension of the gas flow path will not materially change the work of breathing provided the diameter of the path is adequate. It will be associated with a small increase in the dead space which effectively equates with CO2 rebreathing, so keeping it as short as possible is important. If you could calculate the volume and post it I would be able to comment more definitively.

Simon M