Demystifying dry cabinets

Mav · 21st July 2005

I thought I'd share a little on dry cabinets as there does not seem to be conclusive answers on the site. I just got a larger cabinet over the week and this is my conclusion and observations on the whole frustrating affair of setting it up.

Ideal storage humidity

40%. After searching and observing everywhere high and low, I accept this is the 'ideal/standard' humidity for photo equipment.

Moral of storage humidity: As long as it is not above 60% as specified in most camera manuals.

Dial setting

Size of cabinets affect the humidity at any given dial setting. I.e: more space = more air = higher humidity = higher reading. For example, for smaller cabinets, if you set the dial at 12 o'clock, the humidity reads, say, 45%. A larger cabinet at the same setting may yield a higher reading.

Tip: Check the power consumption of the cabinet and you can identify how efficient the dryer is. I.e, don't count on setting the dial at the same position to get the same humidity level for 30L and 60L.

Adjusting humidity level

A new setting will take roughly a couple of hours to stabilize. But I observed that you would only get a true reading overnight. This is the source of all my frustrations actually. So, adjust the humidity without any stuff inside and wait overnight. Check and adjust accordingly. The humidity also changes according to the temperature: lower temp > lower humidity.

Useful tip! (For a certain popular brand of dry cabinets) Wondering what the A, B and C mean? A is 40 - 50% RH, B is 30 - 40% RH and C is 20 - 30%. BUT these are all aprroximates.

Items that asorbs more moisture like paper, cloth, camera pocuh, etc, will throw the cabinet humidity off the scale to as high as 60-70% This is normal. (The cabinet humidity with door closed and placed in my living room, the unit off, read a whopping 95% one day)

Patience is the game here. I took almost a week just to get the humidity I wanted and the reading stabilized.

What to put in

There's no rule here - Wet stuff get dried, dry stuff gets drier. Batteries are fine since high humidity corrodes the terminals, so it's ok. I throw all my photo stash inside there.

Hope this helps to eliminate frustrations in setting up a dry cabinet!

Mav · 21st July 2005

BTW, correct me if i am wrong in any of the above.

Cheers!

Firefox · 21st July 2005

Might be a good idea to get a seperate Hygrometer as well..
The Akarui Digi 90L dry cabinets that my friend and I got came with Hygrometers that were not functioning properly.. Right now, I'm using a sperate unit I ripped off an old dry-box..

espn · 21st July 2005

Depending on the size of the cabinet, readings aren't the same throughout the entire cabinet, that's why larger cabinets have 2 hygrometers.

The ideal storage for photo equipment is 45-55%.

To stablise the readings, one should remove all equipment and leave the air to still once the readings have been reached, then start putting all the equipment in.

me_jul · 21st July 2005

Originally Posted by Mav

I thought I'd share a little on dry cabinets as there does not seem to be conclusive answers on the site. I just got a larger cabinet over the week and this is my conclusion and observations on the whole frustrating affair of setting it up.

Ideal storage humidity

40%. After searching and observing everywhere high and low, I accept this is the 'ideal/standard' humidity for photo equipment.

Moral of storage humidity: As long as it is not above 60% as specified in most camera manuals.

Dial setting

Size of cabinets affect the humidity at any given dial setting. I.e: more space = more air = higher humidity = higher reading. For example, for smaller cabinets, if you set the dial at 12 o'clock, the humidity reads, say, 45%. A larger cabinet at the same setting may yield a higher reading.

Tip: Check the power consumption of the cabinet and you can identify how efficient the dryer is. I.e, don't count on setting the dial at the same position to get the same humidity level for 30L and 60L.

Adjusting humidity level

A new setting will take roughly a couple of hours to stabilize. But I observed that you would only get a true reading overnight. This is the source of all my frustrations actually. So, adjust the humidity without any stuff inside and wait overnight. Check and adjust accordingly. The humidity also changes according to the temperature: lower temp > lower humidity.

Useful tip! (For a certain popular brand of dry cabinets) Wondering what the A, B and C mean? A is 40 - 50% RH, B is 30 - 40% RH and C is 20 - 30%. BUT these are all aprroximates.

Items that asorbs more moisture like paper, cloth, camera pocuh, etc, will throw the cabinet humidity off the scale to as high as 60-70% This is normal. (The cabinet humidity with door closed and placed in my living room, the unit off, read a whopping 95% one day)

Patience is the game here. I took almost a week just to get the humidity I wanted and the reading stabilized.

What to put in

There's no rule here - Wet stuff get dried, dry stuff gets drier. Batteries are fine since high humidity corrodes the terminals, so it's ok. I throw all my photo stash inside there.

Hope this helps to eliminate frustrations in setting up a dry cabinet!

Thanks for sharing! Good to know...
So its better to get the professional series type? Where you can set the humidity and the dry cabinet will adjust itself until it reaches that level inside.
Just a question...how do we know that the hygrometer is accurate? Or how often must we calibrate it?

uncleparty · 21st July 2005

hhmmm won't everything be solved so long as we have get a hygrometer?

dun have to rely on calcuations and hoping they're right.

and then the question now is, where can one get a good and accurate hygrometer.

ps: for me the problem is quite the opposite. my room with aircon on almost 24/7 had a relative humidity which was usually 15 to 25%. my dry box seemed to be my *wet* box instead. lol. but with a fishtank now, it hovers around 50%. just what it does to your skin!

yanyewkay · 22nd July 2005

yah good question.. where to buy a cheap hygrometer

Mav · 22nd July 2005

Originally Posted by yanyewkay

yah good question.. where to buy a cheap hygrometer

Try these places:

- The larger Homefix shops have a range of digital hygro/thermometer.
- Cigar shops have them as well. Try the one at Suntec.
- Sim Lim tower
- Newark-in-one (Farnell).

You can even get precision ones at obsene prices if you want!

smallaperture · 22nd July 2005

Nice article there.

One thing I would like to add - good to fill your dry cab to the max so that you leave as little free air inside as possible. As a result, with very little air inside, each time you open, less air is exchange with the outside and overall humidity rise would be very limited and it will take a much shorter time for the humidity of the air to go back to the set level.

BTW, I tend to open the cabinet at least once or twice a week. The humidity level gets back within a couple of hours.

yanyewkay · 22nd July 2005

Originally Posted by Mav

Try these places:

- The larger Homefix shops have a range of digital hygro/thermometer.
- Cigar shops have them as well. Try the one at Suntec.
- Sim Lim tower
- Newark-in-one (Farnell).

You can even get precision ones at obsene prices if you want!

yes i tried farnell and rs singapore.. those were ridiculous expensive.

will try out options 1-3 this weekend

uncleparty · 24th July 2005

checked out homefix at marina sq today. got two brands for digital.

cheaper brand was 31, more ex one got a few sizes from 40plus to 60plus.

they're all thermometer cum hygro. hope it helps

21st July 2005	#1
Mav Member Join Date: Apr 2004 Posts: 82	Demystifying dry cabinets I thought I'd share a little on dry cabinets as there does not seem to be conclusive answers on the site. I just got a larger cabinet over the week and this is my conclusion and observations on the whole frustrating affair of setting it up. Ideal storage humidity 40%. After searching and observing everywhere high and low, I accept this is the 'ideal/standard' humidity for photo equipment. Moral of storage humidity: As long as it is not above 60% as specified in most camera manuals. Dial setting Size of cabinets affect the humidity at any given dial setting. I.e: more space = more air = higher humidity = higher reading. For example, for smaller cabinets, if you set the dial at 12 o'clock, the humidity reads, say, 45%. A larger cabinet at the same setting may yield a higher reading. Tip: Check the power consumption of the cabinet and you can identify how efficient the dryer is. I.e, don't count on setting the dial at the same position to get the same humidity level for 30L and 60L. Adjusting humidity level A new setting will take roughly a couple of hours to stabilize. But I observed that you would only get a true reading overnight. This is the source of all my frustrations actually. So, adjust the humidity without any stuff inside and wait overnight. Check and adjust accordingly. The humidity also changes according to the temperature: lower temp > lower humidity. Useful tip! (For a certain popular brand of dry cabinets) Wondering what the A, B and C mean? A is 40 - 50% RH, B is 30 - 40% RH and C is 20 - 30%. BUT these are all aprroximates. Items that asorbs more moisture like paper, cloth, camera pocuh, etc, will throw the cabinet humidity off the scale to as high as 60-70% This is normal. (The cabinet humidity with door closed and placed in my living room, the unit off, read a whopping 95% one day) Patience is the game here. I took almost a week just to get the humidity I wanted and the reading stabilized. What to put in There's no rule here - Wet stuff get dried, dry stuff gets drier. Batteries are fine since high humidity corrodes the terminals, so it's ok. I throw all my photo stash inside there. Hope this helps to eliminate frustrations in setting up a dry cabinet!

21st July 2005	#6
uncleparty Member Join Date: Mar 2005 Posts: 255	hhmmm won't everything be solved so long as we have get a hygrometer? dun have to rely on calcuations and hoping they're right. and then the question now is, where can one get a good and accurate hygrometer. ps: for me the problem is quite the opposite. my room with aircon on almost 24/7 had a relative humidity which was usually 15 to 25%. my dry box seemed to be my wet box instead. lol. but with a fishtank now, it hovers around 50%. just what it does to your skin! __________________ Edmund Leong Photography

22nd July 2005	#7
yanyewkay Senior Member Join Date: Sep 2004 Location: Cons digger. Posts: 4,046	yah good question.. where to buy a cheap hygrometer __________________ “How fortunate for leaders that men do not think.” - Adolf Hitler

22nd July 2005	#9
smallaperture Senior Member Join Date: Jan 2004 Location: Catchment Area Posts: 2,423	Nice article there. One thing I would like to add - good to fill your dry cab to the max so that you leave as little free air inside as possible. As a result, with very little air inside, each time you open, less air is exchange with the outside and overall humidity rise would be very limited and it will take a much shorter time for the humidity of the air to go back to the set level. BTW, I tend to open the cabinet at least once or twice a week. The humidity level gets back within a couple of hours. __________________ I love big car, big house, big lenses, but small apertures.

24th July 2005	#11
uncleparty Member Join Date: Mar 2005 Posts: 255	checked out homefix at marina sq today. got two brands for digital. cheaper brand was 31, more ex one got a few sizes from 40plus to 60plus. they're all thermometer cum hygro. hope it helps __________________ Edmund Leong Photography

21st July 2005	#3
Firefox Member Join Date: Feb 2004 Location: Bedok Posts: 716	Might be a good idea to get a seperate Hygrometer as well.. The Akarui Digi 90L dry cabinets that my friend and I got came with Hygrometers that were not functioning properly.. Right now, I'm using a sperate unit I ripped off an old dry-box..

21st July 2005	#4
espn Deregistered Join Date: Dec 2002 Location: Planet Nikon Posts: 22,045	Depending on the size of the cabinet, readings aren't the same throughout the entire cabinet, that's why larger cabinets have 2 hygrometers. The ideal storage for photo equipment is 45-55%. To stablise the readings, one should remove all equipment and leave the air to still once the readings have been reached, then start putting all the equipment in.