Humidity around 45%

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Archive 2009 · Humidity around 45%

fmikio
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p.1 #1 · Humidity around 45%

I keep my gear inside a flipside bag in the closet. I bought those humidity measurers and it's around 40~47%. Is this ok or is it better to have some desincant packs also ?

Thanks !

Nov 09, 2009 at 05:24 PM

Ian.Dobinson
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p.1 #2 · Humidity around 45%

better safe than sorry.

Nov 09, 2009 at 05:46 PM

LynnP
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p.1 #3 · Humidity around 45%

Here in the PNW that would be a dry day. Currently the humidity is 66%. Remember that fog is 100% humidity.
Using desiincant packs is never a bad idea. They may be usless in Death Valley in the middle of summer but they won't do any harm.

Lynn

Nov 09, 2009 at 06:26 PM

UCSB
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p.1 #4 · Humidity around 45%

That is dry ... I wouldn't worry.

Nov 09, 2009 at 06:28 PM

Paul B
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p.1 #5 · Humidity around 45%

Nov 09, 2009 at 09:01 PM

fmikio
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p.1 #6 · Humidity around 45%

In case I buy dessicants (those that I can put in the oven to re-activate), how many of those are necessary in a bag like the lowepro flipside 300 ?

Nov 09, 2009 at 09:16 PM

kodakeos
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p.1 #7 · Humidity around 45%

where do you buy those desiccant bags?
I always save those little ones I get in boxes with electronics and such but they're fragile

Nov 09, 2009 at 11:51 PM

EB-1
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p.1 #8 · Humidity around 45%

Desiccants are avaible everywhere. Do a search online.

However, they are only practical for products in tight containers. In a typical camera bag the humidity will be reduced, but only for hours or a few days.

EBH

Nov 10, 2009 at 12:22 AM

Gochugogi
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p.1 #9 · Humidity around 45%

Only 45%? Sheesh, don't move to Hawaii: it's typically 70-90% and gear does just fine without desiccant. Humans don't fare as well and it makes for a lotta sweaty 'n stinky folk.

Nov 10, 2009 at 12:44 AM

cgardner
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p.1 #10 · Humidity around 45%

The ability of air to to hold moisture is a function of temperature. Relative humidity in the days before electronic devices was measured with a device called a swing psychrometer consisting of two thermometers, one with a wet wick around it. You'd swing it around so the wick would dry, which has a cooling effect. The temperature on the dry thermometer and difference in lower temp on the wet one would be looked up on a chart to compute the relative humidity. When I was a kid my dad, an engineer, used one to measure humidity in our house and I've them to measure humidity in printing plants to cross check the electronic gauges.

40-45% RH indoors at at temp of 20C / 68F is an average comfort level and shouldn't cause any problem with camera gear. Its when RH consistently stays above 60% that mold and fungus start to do the wild thing and multiply.

Warm air holds more moisture and we feel the effects of high humidity more when its hot because it effects the rate sweat evaporates and cools the body. In the winter when the outside air is cooler, the RH will be lower and in homes with out supplemental humidifiers the RH can drop below 30%, which is uncomfortably dry and begins to crack skin, dry out nasal passages and create static charges when walking across carpeted floors. In the summer when the outside humidity is higher and the home is air conditioned the moisture in the air condenses on the cold coils in the air handler and goes down the drain, keeping the RH indoors in a more comfortable range than outdoors.

If you live in topical climate without air conditioning you might have a reason to be concerned. I lived in the Philippines for 11 years (with air conditioning) and never had any problems with mold or fungus, but it was a problem for those there not storing gear in a controlled environment.

Bottom line? If you are comfortable your heated / air conditioned house in Canada your gear will be comfortable and OK too.

Chuck

Nov 10, 2009 at 01:41 AM

fmikio
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p.1 #11 · Humidity around 45%

kodakeos wrote:
where do you buy those desiccant bags?
I always save those little ones I get in boxes with electronics and such but they're fragile

For now I have some spread in the bag that came in electronics and food packages.
But I've seen those that are "reusable" in my local dealer. I can't remember the name but I think it's something with a pink color or it becomes pink/red when it's time to "dry" it in the oven...

Nov 10, 2009 at 02:35 AM

fmikio
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p.1 #12 · Humidity around 45%

cgardner wrote:
The ability of air to to hold moisture is a function of temperature. Relative humidity in the days before electronic devices was measured with a device called a swing psychrometer consisting of two thermometers, one with a wet wick around it. You'd swing it around so the wick would dry, which has a cooling effect. The temperature on the dry thermometer and difference in lower temp on the wet one would be looked up on a chart to compute the relative humidity. When I was a kid my dad, an engineer, used one to measure humidity in our house and I've them to measure humidity in printing plants to cross check the electronic gauges.

40-45% RH indoors at at temp of 20C / 68F is an average comfort level and shouldn't cause any problem with camera gear. Its when RH consistently stays above 60% that mold and fungus start to do the wild thing and multiply.

Warm air holds more moisture and we feel the effects of high humidity more when its hot because it effects the rate sweat evaporates and cools the body. In the winter when the outside air is cooler, the RH will be lower and in homes with out supplemental humidifiers the RH can drop below 30%, which is uncomfortably dry and begins to crack skin, dry out nasal passages and create static charges when walking across carpeted floors. In the summer when the outside humidity is higher and the home is air conditioned the moisture in the air condenses on the cold coils in the air handler and goes down the drain, keeping the RH indoors in a more comfortable range than outdoors.

If you live in topical climate without air conditioning you might have a reason to be concerned. I lived in the Philippines for 11 years (with air conditioning) and never had any problems with mold or fungus, but it was a problem for those there not storing gear in a controlled environment.

Bottom line? If you are comfortable your heated / air conditioned house in Canada your gear will be comfortable and OK too.

Chuck

Thanks for the explanation...
I guess I can rest myself assured that my gear will stay in great shape...

Nov 10, 2009 at 02:36 AM

JohnJ80
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p.1 #13 · Humidity around 45%

fmikio wrote:
I keep my gear inside a flipside bag in the closet. I bought those humidity measurers and it's around 40~47%. Is this ok or is it better to have some desincant packs also ?

Thanks !

For one, the desiccant packs are worthless. They get completely saturated very quickly. They are designed primarily for packing equipment in low humidity environments and then being sealed. They are worthless in a camera bag.

Secondly, it doesn't really matter what the humidity is, if there is humidity in the air and your gear is below the dewpoint, you will get condensation. The humidity is just a measure of how much water there is in the air. Obviously the higher the dewpoint, the closer you are to having condensation.

J.

Nov 10, 2009 at 02:40 AM

RDKirk
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p.1 #14 · Humidity around 45%

Humidity is relative. 45% in your location, Canada, is not the same as 45% in Florida or Texas (of course, AC inside would change that.) But that's pretty dry for a colder location. Dessicants can't hurt, though.

When a hygrometer gives you a reading for "relative humidity," it already take temperature into account...that's what's relative about humidity. To grow, fungus needs 70 percent relative humidity for an unbroken 24 hours. If you lower the relative humidity below 70 percent within any range of temperatures a human can stand for several hours out of every day, you will keep fungus at bay.

If you live in topical climate without air conditioning you might have a reason to be concerned. I lived in the Philippines for 11 years (with air conditioning) and never had any problems with mold or fungus, but it was a problem for those there not storing gear in a controlled environment.

I lived for 12 years between Okinawa, the Philippines, and Hawaii, mostly without air conditioning. In the Philippines, it got so humid during monsoon that we got mildew on the living room walls. I built a simple dry box by putting a low wattage bulb in a cabinet. It worked fine.

Honolulu was no problem at all--rather dry, actually, because of the natural airconditioning and dehumidifying effect of the tropical wind blowing over the mountains from the windward side. The rain clouds nearly perpetually hanging on the mountain tops was all the humidity that did not reach Honolulu.

For one, the desiccant packs are worthless. They get completely saturated very quickly. They are designed primarily for packing equipment in low humidity environments and then being sealed. They are worthless in a camera bag.

This is completely true. Although the seal doesn't have to be airtight (humidity moves with air movement, and if the air isn't moving, neither is the humidity), if you open the bag you get a change of air...there goes the utility of the dissicant.

The most important thing is to take your equipment out of the bags and cases for normal storage. Every story of fungus I've ever heard starts with, "I took my lens out of the bag...."

Nov 10, 2009 at 04:07 AM

fmikio
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p.1 #15 · Humidity around 45%

RDKirk wrote:
For one, the desiccant packs are worthless. They get completely saturated very quickly. They are designed primarily for packing equipment in low humidity environments and then being sealed. They are worthless in a camera bag.

This is completely true. Although the seal doesn't have to be airtight (humidity moves with air movement, and if the air isn't moving, neither is the humidity), if you open the bag you get a change of air...there goes the utility of the dissicant.

The most important thing is to take your equipment out of the bags and cases for normal storage. Every story of fungus I've ever heard starts with, "I took my lens out of the bag...."

I thought that leaving my gear inside the bag, it would be safe...
So, I think I'll have to think of a cabinet or even in the drawer

Nov 10, 2009 at 04:45 AM

cgardner
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p.1 #16 · Humidity around 45%

LynnP wrote:
Here in the PNW that would be a dry day. Currently the humidity is 66%. Remember that fog is 100% humidity.

Fog creation is a function of the dew point. As air temperature increases it can hold more moisture. If you have a warm humid day then a cold air mass rolls in on top of it cooling down the moisture laden air a point is reached where the moisture in the previously warm air condenses - the dew point. Dew will occur first on cool objects, then in the air itself creating fog.

When the weather forecast mentions the dew point the thing to pay attention to is how close the dew point is to the temperature. A dew point of 50 on a 50 degree day in an indicator you will wake up to fog. A dew point of 70 on a 90 degree day means the humidity will be beastly.

Chuck

Nov 10, 2009 at 11:47 AM

cgardner
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p.1 #17 · Humidity around 45%

RDKirk wrote:

I lived for 12 years between Okinawa, the Philippines, and Hawaii, mostly without air conditioning. In the Philippines, it got so humid during monsoon that we got mildew on the living room walls. I built a simple dry box by putting a low wattage bulb in a cabinet. It worked fine.

When I went overseas I put a gun and some things in one of those cheap fire-proof safes in storage in the US. When I got the safe out of storage four years later, the seams on the sheet steel had burst and the door jammed because the fire retardant lining had absorbed moisture and expanded. I had to hack it open with a chisel, sledge hammer and a wrecking bar. The gun was completely covered in rust and everything else was covered with mold and mildew. The rest of the stored effects were OK.

So even with when using moisture absorbing pouches you can't just put them in and forget them. At some point the moisture they will absorb will start to do more harm than keeping the gear out in the circulating ambient air.

Chuck

Nov 10, 2009 at 12:03 PM

fmikio
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p.1 #18 · Humidity around 45%

Hum... I see...
There's another thread about an Ikea cabinet invention. I guess I'll take a look at that to store my gear...

Nov 10, 2009 at 12:50 PM

fmikio
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p.1 #19 · Humidity around 45%

Also, about the condensation.
It was kinda 5 celsius one of these days when I went outside to shoot some pictures. I stayed outside around 2 hours and when I came back home, my camera and the lens were cold. I was afraid of touching them with my warm hands and create condensation inside. This is something I'll have to take care when I come back from below 0 temperatures. I guess, leaving it inside the bag for some hours and let it warm to the room temperature would be sufficient ? Or should I put them in a plastic bag *before* entering home ?

Nov 10, 2009 at 12:56 PM

RDKirk
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p.1 #20 · Humidity around 45%

I guess, leaving it inside the bag for some hours and let it warm to the room temperature would be sufficient ?

Yes.

Or should I put them in a plastic bag *before* entering home ?

No.

Nov 10, 2009 at 01:08 PM

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