Question on humidity

[Kryptos]

Where I live the humidity levels are not very high in general:

Johannesburg-South africa

Month Relative humidity

am pm

Jan 75 50
Feb 78 53
March 79 50
April 74 44
May 70 36
June 70 33
July 69 32
Aug 64 29
Sept 59 30
Oct 64 37
Nov 67 45
Dec 70 47

How usefull would a dehumidifier be in these conditions? And how well suited are the conditions here in terms of medal and cloth storage?

I managed to find that the idea humidity is around 60%? Is that correct?

[Paul R.]

In my world of conservation. The ideal Relative Humidity should be between 43%-45% 24/7 365 a year.
Anything higher will cause damage. Lower humidity will cause shrinkage. It best to moniter these conditions daily.

[N.C. Wyeth]

Paul,

What is your suggestion for raising humidity inside a relatively small sealed space (roughly 24 cubic feet)? Most of the year it maintains a 45% RH, but during the Winter months it drops to about 38% to 40% . . .

Keep in mind that it is sealed - not perfectly, but close . . .

Brad

[Paul R.]

N.C. I use very sparingly a small humidifier. For very short intervals on the lowest setting and away from any military items.

[Kryptos]

Hmmm thanks for the info. Will have to look into creating a properly monitored display space for them. At the moment they are locked away in a container (only started recently).

Great to have the ideal range.

Are there any systems available that will maintain this atmosphere for you, rather than have you fiddle with humidifier and then dehumidifier? But I suppose those would be unpayably expensive.

[Paul R.]

Yes, There is such a system like that. Yes, you are talking major investments. Several museums that I work at have them, but you still have to moniter them daily. One place that I had worked hooked it up to and alarm system. If it went above or below the level it would sound off. I am sure that route is less expensive. Paul

[Kryptos]

Will need to see what I can find to fit my budget for this.

With a manual controlled system, how difficult is it so establish equilibrium? And how long will the container hold that humidity?

Dont want to end up with a situation where I have to spend half my day messing with humidifier/dehumidifier LOL