Calibrating an Ultrasonic Humidifier for Glycol Vapors |
August 26th, 2025 |
airquality, glycol |
I got a random cheap humidifier on Amazon ($30) but (a) TEG is more viscous than the water its designed for and (b) its output is probably higher than I need. I decided I'd dilute the TEG to resolve both of these.
First I tested with just water, and I used distilled water because these humidifiers can turn the minerals in tap water into a fine dust it's better not to breathe. I filled the humidifier, weighed it, ran it for an hour on high, and weighed it again. I measured it losing 122g (2g/min), though this is likely an overestimate: instead of weighing the whole device before and after (like I did later) I weighed how much water I poured in (accurate) and then weighed what was left (inaccurate, due to not all the water coming out).
Nix fits a photo op into his busy
campaign schedule
My goal is a concentration of about 1mg/m3 in a stream of 8,000 CFM of incoming air. Converting 8,000 CFM to m3/min I get 227 m3/min, so to put out 1mg/m3 I need 227 mg/min.
If TEG+water behaves similarly to water I should combine six parts water with one part TEG by mass. But the higher viscosity of TEG means it vaporizes more slowly, and after some trial and error I landed on three parts water to one part TEG. In a 60min test I measured mass decreasing by 56g, which is 0.233g/min (56g / 60min * 25% TEG).
This is way closer to my target (0.233g/min vs 0.227g/min) than I had any right to expect, and I don't expect it to be quite this close in practice.
For the 2025-09-07 dance I'm planning to mix up 3:1 TEG to distilled water at home, where I have a scale. I'll want about 300g, so I can turn it on as soon as we turn on the fan and not worry about running out.
Note that these figures are all for a large dance hall with thousands of cubic feet of air coming in every minute. So literally don't try this at home: this is way too high a concentration for your living room.
Comment via: facebook, lesswrong, mastodon, bluesky