I've been wondering how much vapor enters my lungs during vaping, so I decided to measure it, or at least estimate it. I haven’t seen this topic in the forums, and I am not sure it is of interest, but thought I would share.

Bottom line: about 1.4 liters.

Details
I connected a small flow meter to my atomizer via some tubing, as shown in the first picture. I then drew air through the atomizer and flow meter at different rates, starting after an exhale. Some details:

Mod box: Aegis Mini
Atomizer: Wotofo 1.5 equipped with SS e-mesh, holes half open
No heat, no spice

The first graph shows my inhale time at different flow rates. There is a lot of scatter in the data. Not surprising considering how crude the setup is. I inhaled to a fullness consistant with vaping, about 80% to 90% of full.

The lung capacity is the product of the flow rate and time. For instance, a flow of 6 liters per minute for 10 seconds would yield 6 lit/min x (1 min/60 s) x 10 s = 1 liter. The second chart shows the calculated lung capacities for each data point. They range from a bit over 1 liter to just under 2 liters with an average of 1.4 liters.

I looked online and found lung capacity is defined in different ways. The total volume the lungs can hold is around 6 liters for men and 4.2 for women. A more relevant measure is the Inspiratory Capacity, which is the maximum amount of air that can be inhaled after a normal exhale. It is around 3.6 liters for men and 2.4 for women. I think my number is lower for several reasons: I was only inhaling to 80% or 90% of capacity; my system has a lot of resistance from the tubing, flow meter, atomizer, and I am old (capacity drops with age).

Next I fit the data to a very simple model: flow rate x time = capacity, with capacity as the adjustable parameter. The last plot shows the fit, along with 90% confidence limits. From the fit I can calculate my flow rate during a 10 s draw: 8.5 +/- 0.8 lit/min.

I'm sure someone with a more professional setup could bring a lot more accuracy to this, but it is nice having a rough idea.

Ha! This is pretty awesome. I like the idea. I used to be a swimmer, so naturally am a little curious about my own.

Thank you for still being so detailed in your results, even if you feel your set up is crude. If I can get some extra cash and spare time, I may test it for myself.

Perhaps others will too and share their results.

One love

I absolutely love this. It's what the Nexus was created for! Experiments! Data! Research and Development!

My lung capacity is complete garbage from smoking cigarettes, and is one of the primary reasons I'm having a difficult time breaking through. I simply can't hold in enough. I need to quit smoking.

You could try this way to get a second opinion:

Inhale through vape as before, but exhale into tube that bubbles up into a water filled inverted measuring vessel that is itself under water. Then read off the air volume.

Main problem is finding a suitable measuring vessel for such a large volume I guess, but anything based around multiplying a measured rate by time, like your stated method, will be pretty sensitive to rate errors, so this should provide an alternative to compare by.

Good stuff! Keep on being curious

Cheers,
frac4

I just thought of a tweak to the water displacement method I give above:

Have the underwater inverted collector as mentioned, but have it in a vessel that is full to the brim. As you breathe into the collector then the same volume will overflow the main vessel. Collect that and you have your breath volume.

Obviously a fair bit of missing implementation detail in the above glib description, but it can be very low tech at least and could be fun to try

Thanks all for the encouraging words. And thanks fractals4life for the alternate method. I would love to try it, but I would need to use my bathtub, and I hate to waste the water. (I am in a drought area.) I may anyway. I really like this idea.

BTW, I just posted some more experimental results here.