question concerning humidity levels

[panzerman]

I just moved my entire collection to my basement last Winter. Now I have 1800 sq. ft. of room for the 20 cabinets, 400+ drawers, plus future expansion. Another great thing, no sunlight gets in. However, even though we have air conditioning, the humidity levels are about 30 in the Winter, 65 in the Summer. Is 65 too high? Otherwise I will need a dehumidifier.

John

[Deleted]

Hi John,

I have my entire (albeit smaller) collection of 200+ drawers/24 Shadow-boxes in the basement and have for years. 65% is the absolute top allowable amount of humidity. 65% is better than 80% humidity, but not as good as 50%.

Just to play it safe with a massive collection as your's, I'd suggest you keep it around 50%. Mine is set to maintain the room at between 45% and 50%. In the winter, the temps are lower and the dehumidifier won't work effectively, so I settle for about 55% humidity then. My basement has two dehumidifiers--one for the general basement and one just for the insect room. Your 1800 sq.ft. is a large area to keep dry--you may have to adapt somehow. I wish I had such a large area for the collection

This is merely my 'take' on the question you put forth. Others may disagree. Generally...as I see it....the drier, the better.

[Adam Cotton]

Definitely "the drier, the better" as Bill says.

65% humidity is verging on the dangerous, and I would certainly recommend putting one or more dehumidifiers in the collection room. It is also worth considering that air movement around the room helps, as otherwise you may find some parts of the room will have much higher humidity levels than others.

Adam.

[prillbug2]

I have two humidifiers and a couple of fans running at full power, when I don't have my air conditioner on during the summer. But every once in awhile, you do find some fungus breaking out once in awhile. And since I have ten cabinets down in my basement, it takes me a little while to check everything. So, actually, silicon gel still helps alot with larger collections.
Jeff Prill

[panzerman]

Thanks a lot guys!

I will get a dehumidifier today. Humidity level was at 58 this morning, adding the dehumidifier should get it down around 45-50 level.

John

[Adam Cotton]

John,

Good luck, I'd recommend getting a fan to move the air round the room at the same time. I think 50% humidity is the absolute maximum you should be aiming for.

Keep an eye on the specimens in the bottom draw of each cabinet, as that's where the mould usually develops first. Some museums traditionally keep the bottom draw in each cabinet empty deliberately to avoid this problem.

Adam.

[prillbug2]

Also you need to keep checking moths and butterflies, especially those that were purchased, because humidity has a tendency to cause the nice mounting job to pull the wings up or down due to gradual relaxation. So, that nicely mounted Papilio zagreus might be in a V-shape some day. It doesn't matter where it is in the cabinet, the muscles start to relax little by little over time, and you have to keep track of it. But you can always respread it.
Jeff Prill

[panzerman]

I got a dehumidifier. Man, it sure worked, in 24 hrs it dropped the humidity from 59 down too 52, after 48 hrs its now at 48. I will try to aim to get it down to 40.


John

[downundermoths]

Humidity is a problem sure, but not the major disaster thing that many of you believe it is. My insect room is at 74% right now, which is high. During the really hot, sweaty months when humidity can go up to 85% or more ,I run the aircon all day and keep it down to about 60%. I have very little trouble with wings folding back up, or fungus attack. If on the rare occasion I see fungus (regular checks are really important) I gently wet the infected parts with ethyl acetate through a fine syringe and that fixes it...

Barry

[Deleted]

just seen ths post, I have just finished the MAMMOTH job of resetting 1500 specimens because I did not keep an eye on mine for 6 months between house moves, you have been warned.