Can PG/Foam LOWER rh?

[Hammerhead]

Just curious. I have a new humidor that came with a PG/foam humidification element, but it seems every time I put it in the box, the RH drops. I've always used Viper's beads, and have 2 tubes in there now, but just thought I'd leave it in there until I buy more and can replace the foam.

[RcktS4]

Originally Posted by Hammerhead

Just curious. I have a new humidor that came with a PG/foam humidification element, but it seems every time I put it in the box, the RH drops. I've always used Viper's beads, and have 2 tubes in there now, but just thought I'd leave it in there until I buy more and can replace the foam.

This is strange - as I understand it, PG will absorb and/or expel H2O to regulate humidity at 75%... it should lower humidity only if it is higher than 75%, and raise it if it is lower.

If the PG in the foam is "saturated" it will no longer be able to lower humidity as there is no un-bonded PG left. This would result in high humidity. If there is no water left, the PG cannot raise humidity, and this would result in dropping RH.

But what you are describing is that the addition of PG causes RH to drop lower than 75%? This should not be possible. At <75% PG will expel water. At >75% it will absorb. It should not, under any circumstances I can understand absorb water below 76% RH.

Two "idiot checks":
1) is the RH drop actually just due to lower RH air being introduced when you are opening the humi?
2) could your hygrometer be wrong?

[Hammerhead]

Raney, sorry... should have been more clear. I'm using the humiditication element as-is, in the same condition as received from the former owner. So, if I'm interpreting your post correctly, if the prior owner oversaturated with PG, then it's entirely possible that the element might lower the RH.

The hygrometer is a Western CalIII salt tested to +1.

[Dr. Stogie Fresh]

The beads could be adsorbing water, so could the SC in the box. If your box had reached an equilibrium prior to inserting the humidifier, could be that the box and beads are compensating.

If you don't have the beads in at the same time as the foam humidifier, then it could be oversaturated with PG.

The Doc

[RcktS4]

Originally Posted by Hammerhead

Raney, sorry... should have been more clear. I'm using the humiditication element as-is, in the same condition as received from the former owner. So, if I'm interpreting your post correctly, if the prior owner oversaturated with PG, then it's entirely possible that the element might lower the RH.

The hygrometer is a Western CalIII salt tested to +1.

It should only be able to lower RH if it is above 75%... It is not possible for PG to lower humidity below 75%. Humidity may drop lower if there is no water for the PG to "donate", but this would not be BECAUSE of the PG, but would be because of either the beads or the environment (which in my house is around 30-40% right now). Does this make sense?

If the PG is "dry" you just add some more distilled water... maybe add a little to the element and see if this helps. The problem, though, is that the PG element and the beads are going to work against each other until either:
1. the beads will deplete the PG element (in which case the RH should level out at 65 or 70, depending on the beads)
2. the PG element 'saturates' the beads,and the humidity settles at 75%.

[Hammerhead]

Gotcha.

It's probable the box wasn't fully seasoned when I got it. I removed the PG unit and replaced it with a damp paper towel on a plate. RH creeping up again, so my guess is that it just needs some time. My assumption was that because it was in use, it'd be ready, but maybe the trip dried it out some, and sealing the humidification unit in an enclosed package didn't help.

Thanks! I think we figured it out.

[TypeO-]

I've read that continuosly replenishing your humidifier with PG is bad. Recommendation is to use distilled water periodically.

[plexiprs]

Originally Posted by TypeO-

I've read that continuosly replenishing your humidifier with PG is bad. Recommendation is to use distilled water periodically.

Correct, establish a new "Credo" with the 50/50 and then only add water, a couple drops at a time. The PG doesn't evaporate at near the same rate as water. If you over do the element with PG then it must be air dried completely and recharged with fresh 50/50.

[Alpedhuez55]

The Oasis foam can also get clogged up. Before switching to beads, I used to uen up my humidifier and change the foam every year or two.