On bags and volume (a few thoughts)

[Deivis]

I'd like to raise this question:

All books available suggest that you have to have a steady flow of gas for at least 15-20 minutes.
While not undermining their experience, I reserve the right to argue and here is my point:

Most books talk about small-sized bags - turkey/oven bags.
Indeed, with such small closed space you have to constantly flush CO2 out.

However, my humble opinion is that taking a much larger bag would not require a flow.
It's easy to demonstrate: take a flat party balloon and exhale your full lungs to it.
Thats the volume of your lungs.
Now take a big-sized bag - 50x40 inch, or at least 90x80 cm and fill it with air.
Compare the difference. Your lungs are probably 1/100 of it ? You can do more precise calculations yourself, in liters.

If bag is filled with N or He and secured with rubber bands, I think there will be no noticeable buildup of CO2.
It's within a margin of few percent. I'll do more research soon and talk with scuba divers on that.

You may ask - why bother?
My answer is - I see a lot of people being reluctant to buy a tank, mess with flow regulators, and so on.
If my argument is correct, you can get away even with Helium party balloons - I'd call it a "poor man's way out". It may cost - what - 20 or 30 bucks to buy the balloons and fill the bag (assuming the He is not adulterated with other gases).

You are welcome to comment!

 

[Ssname]

Lots of helium balloons are mixed with oxygen now rather than pure helium so that is always a concern.

By having the environment constantly refilled with the gas it flushes out any CO2 or O that you exhale.
If I understand your method you are meaning to fill one big bag from the balloons? I think it would be impractical and lead to a lot of the gas escaping and making it hard to know what gasses you actually have in the bag.