Breathing Ease Avalung vs. Avalung Pack

**robnow** · 10-14-2007, 06:43 PM

I bought the BD Anarchist pack with built in avalung last season. Great pack and great concept. Only problem is, when the time comes to actually use the avalung, I think it'll be damn hard to breathe in because the tube is so long and you'll be breathing quickly from skiing and stress. I'm fit and don't breathe comfortably when practicing with it.

My question is has anyone owned/used both avalung and avalung packs? It seems like the tube on the avalung is much shorter than that of the pack which, I assume, would make breathing much easier.

Is this the case? Thoughts?

As much as I like the pack, I'll probably sell it because I REALLY think it'll be too difficult to use in case of avy and if just an avalung is easier, get that.

**Skidog** · 10-15-2007, 09:02 AM

I would guess that you're right due to length of tubing it would be harder to breath, however it also gives the advantage of putting the CO2 farther behind you.

My guess is that even labored breathing in an avi is better than no breathing, and you need a pack anyway so kill two birds with one stone.

I might be interested in the pack though should you choose to sell.

M

**cj001f** · 10-15-2007, 09:19 AM

Originally Posted by Skidog

however it also gives the advantage of putting the CO2 farther behind you.

Since that would be the principal behind the Avalung is to draw in air and expell the CO2 into a different portion of the snowpack, that would be a good thing TM

**robnow** · 10-15-2007, 09:34 AM

One thing I never thought about is the air intake is pretty much the same distance on both. Avalung being on your chest and pack being on your shoulder which would mean breathing should be the same for both.

Skidog - I'll see, I have the small but should have got the larger one but they weren't available around here.

Funny, BD is the only stuff I've ever seen that is the same price here in Canada as it is in the States. And that was last season before dollar parity hit.

**stew130** · 10-15-2007, 09:49 AM

[QUOTE=robnow;1474354]One thing I never thought about is the air intake is pretty much the same distance on both. Avalung being on your chest and pack being on your shoulder which would mean breathing should be the same for both.

You're absolutely right. The intake is the same. Only the exhaust tube is longer which won't effect your inspiratory effort or the quality of inhaled air.

**KnuckleDragger** · 10-15-2007, 10:03 AM

Actually the longer the distance between the mouthpiece and the inhale/exhale separation valve the harder it will be to breath because there will be more exhaled air remaining in the tube that must be breathed back in before you get to the fresh air. I dont think this should be a problem if you can take deep breaths.

**robnow** · 10-15-2007, 10:09 AM

Originally Posted by KnuckleDragger

Actually the longer the distance between the mouthpiece and the inhale/exhale separation valve the harder it will be to breath because there will be more exhaled air remaining in the tube that must be breathed back in before you get to the fresh air. I dont think this should be a problem if you can take deep breaths.

Yeah, that is what I said originally, until I realized that the distance b/w mouthpiece and separation valve is pretty much the same on both the Avalung and Pack. It is the exhaust after the valve that is longer on the pack than the avalung.

**stew130** · 10-15-2007, 10:16 AM

Originally Posted by KnuckleDragger

Actually the longer the distance between the mouthpiece and the inhale/exhale separation valve the harder it will be to breath because there will be more exhaled air remaining in the tube that must be breathed back in before you get to the fresh air. I dont think this should be a problem if you can take deep breaths.

That part of the tubing is known as the dead space and unless I'm mistaken it's the same on both.

**Core Shot** · 10-15-2007, 01:46 PM

the perceived friction of that slightly longer exhale tube aint nothing compared to the friction of breathing in and out of the snowpack itself.

Your best advice is to not need to use it.
Dont let an avalung let you make decisions you would not make without it.

**robnow** · 10-15-2007, 05:04 PM

Originally Posted by Core Shot

Your best advice is to not need to use it.

Believe me, I would never want to actually have to use it especially considering its difficult enough to use in practice. Fuck that would be freaky!

**lazy_pete** · 09-26-2010, 11:01 AM

Hi there,

I know this is an old thread, but just in case anyone gets alerts I'll ask anyway, as this is the only hit I get googling with my question.

Someone quite rightly mentioned above that the volume of tubing between the mouthpiece and the inspiratory/expiratory valve is termed 'dead space'. Thus one has to move this volume of gas, containing CO2 and a hypoxic mixture, before inspiring fresh gas with the normal 21% O2 and preventing 'rebreathing'.

I'm wondering if anyone knows the volume of dead space in an avalung system and therefore how large a tidal volume is required in order to prevent rebreathing. I'd imagine taking large breaths is not that easy when you've been buried under tonnes of snow, and wondered how folk coped potentially breathing a hypoxic mix for a period of time?

Any answers / thoughts much appreciated. I'll try emailing BD as well in case they feel like offering up some trade secrets!

I must get hold of an avalung system to test sometime.

Cheers,

Pete

**lynchdogger** · 09-26-2010, 02:54 PM

Originally Posted by Core Shot

the perceived friction of that slightly longer exhale tube aint nothing compared to the friction of breathing in and out of the snowpack itself.

Your best advice is to not need to use it.
Dont let an avalung let you make decisions you would not make without it.

+1!!! Make good decisions.

**bovine** · 09-29-2010, 06:10 PM

Last season I bought an avalung (not a pack). Prior to getting it I had some doubts as to how much of a hassle it would be to use because of layering and it being another thing around my body to deal with.

It turned out to not be a hassle and I'm glad I have just the avalung harness.

I'm not necessarily an everyday snow pit digger. But when I did last season I'd take off my pack to get my probe, saw and shovel, set the pack aside...

Even though pit site selection is generally to be made in a safe zone, sometimes in order to get a valid representation of the snow we're skiing, it may be necessary to put yourself at risk at times.

I liked having the avalung on me while digging pits-as opposed to taking off my avalung pack to dig one.

-just my 2 cents-and as far as breathing through it, I don't have any trouble

**mr_gyptian** · 09-30-2010, 01:44 PM

i just recently heard that the avalung does not work properly in conjunction with a pack? I heard this from a very informed source.

**hot.carl** · 09-30-2010, 03:10 PM

Originally Posted by lazy_pete

I'm wondering if anyone knows the volume of dead space in an avalung system and therefore how large a tidal volume is required in order to prevent rebreathing. I'd imagine taking large breaths is not that easy when you've been buried under tonnes of snow, and wondered how folk coped potentially breathing a hypoxic mix for a period of time?

Pete

The average male's tidal volume is about 5L this is easily more than enough to push out the maybe 200 ml between the 2 way valve and mouthpiece. Also eventhough it is not a guarantee you would assume that when buried, you would not be at maximum expiration. Even if you are winded this does not mean that there is no air in your lungs, your diaphragm is temporarily spasming so when it recovers you will be able to breathe again. Regardless of pack or plain avalung I am sure that BD would have fully tested them for this sort of issue. I would not worry too much about it

**hutash** · 10-01-2010, 10:04 AM

Originally Posted by mr_gyptian

i just recently heard that the avalung does not work properly in conjunction with a pack? I heard this from a very informed source.

Care to elaborate?

As for tidal/dead space volume, it is not very different from use a snorkel skin diving (or powder skiing), and after 40 years of using a snorkel I have never had a problem with tidal volume and dead space.

**Kya** · 10-01-2010, 08:20 PM

I think it would matter whether your breathing in through your mouth or your nose. In the ideal scenario you are breathing in through you nose and out through the mouth piece, so the length of tube shouldn't really matter.

**cat in january** · 10-02-2010, 06:26 AM

Originally Posted by Kya

I think it would matter whether your breathing in through your mouth or your nose. In the ideal scenario you are breathing in through you nose and out through the mouth piece, so the length of tube shouldn't really matter.

From what I have read it sounds like your nose is often jammed with snow.

**hutash** · 10-02-2010, 09:29 AM

Plus you are supposed to wear the little nose plug BD provides with the avalung

**cat in january** · 10-02-2010, 11:40 AM

Originally Posted by hutash

Plus you are supposed to wear the little nose plug BD provides with the avalung

I know I laughed when i saw that with my pack, thinking about skiing with a nose plug. Just goes to show lawyers can make things happen which make no sense.

**XtrPickels** · 10-02-2010, 07:09 PM

Originally Posted by hot.carl

The average male's tidal volume is about 5L this is easily more than enough to push out the maybe 200 ml between the 2 way valve and mouthpiece. Also eventhough it is not a guarantee you would assume that when buried, you would not be at maximum expiration. Even if you are winded this does not mean that there is no air in your lungs, your diaphragm is temporarily spasming so when it recovers you will be able to breathe again. Regardless of pack or plain avalung I am sure that BD would have fully tested them for this sort of issue. I would not worry too much about it

These figures are unfortunately incorrect.

tidal volume is closer to 500mL. (Normal everyday back and forth breathing.)
FVC is closer to 5L. (The most you can possibly breath out after the biggest possible breath in.