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CCTV Camera Fogging

09/10/2010 10:58 AM

What humidity level will cause cctv cameras to fog inside the dome? I have an outdoor rated camera in a beer cooler with its temperature at 38 F. The camera has condensation inside the dome. The heating element inside the camera kicks in at 14 F. Packets of silica gel do not help.

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#1

Re: CCTV Camera fogging up

09/10/2010 11:31 AM

Assume the dome is sealed after installed on base.

What color is the stuff inside the gelpacks? Pink or blue. If pink, they are saturated and need to be regenerated.

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#2

Re: CCTV Camera fogging up

09/10/2010 11:45 AM

you could try making yourself a quick and dirty glove box and purging the unit with either argon or dry nitrogen and then reassembling it with rtv to seal any holes.

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#3

Re: CCTV Camera fogging up

09/10/2010 12:00 PM

I maybe wrong but I think that by definition 100% humidity is when fogging occurs. Now I'm mildly surprised that a heating element would turn on at 14°F because by this time ice would have occurred with any moisture in the camera. I also do not understand what you mean by a "beer cooler". Is this a large walk-in refrigerator that cools only beer at a beverage distributer or supermarket? Is the camera inside this refrigerator a security camera? Then you may have to relocate the camera away from the door so that the moist outside air does not condense on the camera parts. If instead your "beer cooler" is instead a surveillance box and the moister air inside your surveillance box is condensing on the inside of the dome, then you should instead properly ventilate the air inside your dome so that it cannot have more water than the air outside the dome.

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#4
In reply to #3

Re: CCTV Camera fogging up

09/10/2010 12:20 PM

Beer Cooler is a walk in cooler at a supermarket. Agreed 14 F is to low of a element turn on point, other than the fact the circuitry of the camera provides heat through wattage of operation. Re-locating camera is not an option for best surveillance operation. Plan on testing for 1 week removing dome alltogether.

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#5

Re: CCTV Camera Fogging

09/10/2010 2:14 PM

Is this cooler open to the public. From the experience entering walk-in coolers open to public use they are very damp inside. The humidity coming in with people opening and closing the door. This would condense on anything cold including the glass the dome made of. You may need to place some type of heating device inside the dome to warm the glass. If you look they may offer them heated for just that application.

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#6
In reply to #5

Re: CCTV Camera Fogging

09/10/2010 2:20 PM

And if you remove the dome the fog will condense on the lens and the electronics making things MUCH worse.

you need to set the thermostat on the heater to a much higher temp.

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#8
In reply to #6

Re: CCTV Camera Fogging

09/10/2010 3:03 PM

remove the dome?

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#9
In reply to #8

Re: CCTV Camera Fogging

09/10/2010 3:07 PM

Sorry, should have been a response to #4. OP was talking about removing the dome over the camera.

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#11
In reply to #6

Re: CCTV Camera Fogging

09/10/2010 3:28 PM

Have done it numerous times with NO fogging on camera lens, Electronics have lasted as long as other cameras in non refridgerated sections of building.

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#7

Re: CCTV Camera Fogging

09/10/2010 2:24 PM

turn the heater off.

if its cold outside and cold inside the dome there will be no condensation so long as the camer ptz doesnt freeze.

when you put a heater inside a small box and then place it in a freezer condensation will form.

turn the heater off.

let me know what happens.

I know about this becuase i worked for a food processing company who had problems with a computer terminal inside a cold envoiroment and to stop condensation they fitted ever bigger heaters in side

until i tried turning them all off problem solved.

think outside the box or camera dome

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#10
In reply to #7

Re: CCTV Camera Fogging

09/10/2010 3:11 PM

Just in case you ask whats ptz its Pan Tilt Zoom

If its a fixed cam there is nowt to freeze the shutters in CCD are an electronic function and not shutters as in an old type camera

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#13
In reply to #7

Re: CCTV Camera Fogging

09/11/2010 12:17 AM

Can you please explain the physics of turning the heater off? This is counter-intuitive to me! There is a logical physics reason the heater is there in the first place!

The placement of the heater and its thermostat setting are probably critical.

To the OP: are you sure that thermostat setting was in degrees Fahrenheit? 14° C would be a much more logical setting, to my way of thinking...

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#14
In reply to #13

Re: CCTV Camera Fogging

09/11/2010 4:34 AM

Can you please explain the physics of turning the heater off? This is counter-intuitive to me! There is a logical physics reason the heater is there in the first place!

COUNTER INTUATIVE TO YOU!! NOT ME

Why is the heater there in the first place, to stop the insides freezing but if there are no moving parts there is nothing to freeze is there ??

The heater is there to keep the inside dry, but as its in a freezer the dew point would be low but adding a heater in those situations is making matters worse.

If the air temp inside the dome is the same as the outside there cannot be any misting can there, you only get condensation when there is a difference in temp, No diffrence no condensation.

WHATS SO HARD TO UNDERSTAND ??

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#19
In reply to #14

Re: CCTV Camera Fogging

09/11/2010 10:02 AM

The OP indicated the problem is fogging, not freezing. It is a cooler, not a freezer, with the temperature set at 38°F, so freezing should not be an issue. We don't know whether the camera is a PTZ or fixed, but the mention of a dome would suggest that it probably is. (By the way, thanks for defining PTZ).

The wording of the OP indicates that it is the camera (lens) that is fogging, rather than the dome, although I'd ask for a double-check on that. If indeed the camera is fogging, and the dome is not, then water must be entering the dome somehow, or was already there before the dome was sealed, assuming it is sealed.

We have no idea of the location/environment where the OP lives/works, or how often people enter/exit this cooler. I am assuming that this is a walk-in cooler, as it would not likely be worth the trouble to install the camera in a smaller refrigerator. You are quite right that condensation can not occur unless the condensation surface is cooler than the nearby air, so removing the dome would make sense in a cooler where people rarely enter or open the door. On the other hand, if the door is opened frequently, then new humid air will enter each time and condensation will occur. keeping the camera slightly warmer than its surroundings should prevent condensation, so adjusting the heater thermostat to something around 40°F should stop the condensation with very little heat energy required.

Another item that should be mentioned is how and where is the unit mounted? Such cameras are commonly mounted on or near the ceiling. Since humid air is lighter than drier air of the same temperature, the humidity will tend to be greatest near the ceiling. Mounting the unit a bit lower might help.

Finally, if the camera is mounted IN the ceiling, with its cable extending upward into an uncooled space, water will be condensing on that cable and may be wicking down into the dome.

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#21
In reply to #19

Re: CCTV Camera Fogging

09/11/2010 11:33 AM

All good points. Until the op comes back with more info we can do no more.

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#22
In reply to #21

Re: CCTV Camera Fogging

09/11/2010 1:33 PM

Peter,

You should know better than that. We can go on for weeks and months without any further input from the OP. Heck, we can quickly convert this or any thread into a silly discussion on any possible tangential thread that has only the most remote tie back to the original question. Just the emoticon additions can continue a thread going for days. Just look briefly at our bath breaking thread and you'll see what I mean.

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#23
In reply to #22

Re: CCTV Camera Fogging

09/11/2010 2:36 PM

I am sure i Dont know what you mean hehehehe

But i had to ask on the remote chance we actually get an answer.

One day it will happen and we will be so confused we wont be able to answer.

Now heres a thought

i figure the camera is to stop people stealing the cans.

Why not put pictures of the cans and put a number code below each photo/display.

than get the shoppers to ask for 6 cans of 0021 or whatever the code is for that item please.

put the shop/til operator behind bullet proof glass, and have a bank type chute where the shopper can collect their goods once they have paid.

now let the B***ards steal the stuff.

Oh and a notice sayng display cans have poison in them and are booby trapped, and have some wires going to dummy ( or not) claymores

oh and remote controlled machine guns in the ceiling.

And a gun rack behind the till (dummy guns of course)

and steel self closing doors to lock perp in if theres a dispute, and gas canisters to keep them quiet.

now watch the stock loss fall.

Very off comment

pps i have seen an off licence here in uk

where you walk down a glass lined walkway with the display ether side,

You have to point or describe what you want, pay, then you get your goods.

They dont have any touble with shoplifting now.

Funny that

ps going out now

Not to buy a beer its too dangerous.

I will c if i can find some minefield i fancy a poke around,

Very Very off topic

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#24
In reply to #23

Re: CCTV Camera Fogging

09/11/2010 2:57 PM
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#26
In reply to #22

Re: CCTV Camera Fogging

09/12/2010 10:43 AM

"Just look briefly at our bath breaking thread..."

Woof. 18,815 posts today. Might be more that a brief review..

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#15
In reply to #13

Re: CCTV Camera Fogging

09/11/2010 4:57 AM

Can you please explain the physics of turning the heater off? This is counter-intuitive to me! There is a logical physics reason the heater is there in the first place!

The placement of the heater and its thermostat setting are probably critical.

NO THEY ARE NOT,,,,,THEY ARE THE PROBLEM!!!!!!

found a cctv unit made for freezers note it does not have a heater.

Below taken from data sheet of Camera

Voltage Supply 12 to 24 AC/DC

Power Consumption 2 W or less

Internal Heater / Cooler Not Required

the data sheet in question

http://www.sourcesecurity.com/docs/fullspec/EX14MX4V0408BN.pdf

http://www.sourcesecurity.com/technical-details/cctv/image-capture/cameras/bosch-ex14mx4v0408bn.html

http://www.sourcesecurity.com/markets/industrial-and-commercial/application/co-289-ga.922.html

The heater is not required inside a walk in freezer

the camera the OP has is not suitable for the purpose, it is an outside unit, the heater is there to keep the inside free from dampness.

where he has it mounted the heater is causeing the problem turn it off

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#17
In reply to #13

Re: CCTV Camera Fogging

09/11/2010 8:19 AM

Peter has a good point. However, it depends on whether the camera will operate properly at freezer temperature. The problem is to maintain the dew point of the internal dome gas below the surface temperature of the dome. Removing the silica gel is a start. There may be additional sources of moisture inside the camera assembly. These can be baked out at low temperature. Also, dry gas can be slowly flowed through the dome until everything is sufficiently dry. One dome volume per hour would be a good flow rate to start with.

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#18
In reply to #17

Re: CCTV Camera Fogging

09/11/2010 8:25 AM

another thought, the dome would be there to protect the camera from the elements ie rain, and also to protect against being touched.

now as its unlikely to rain in there then thats not an issue

and if its high up that also is not a issue

so try removeing the dome as others have mentioned, then the problem should be resolved

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#12

Re: CCTV Camera Fogging

09/11/2010 12:12 AM

You should buy a specific dome camera for that temperature. They have some heating resistors in it and 3 fans. I have a client here who drops them down a few times per year. That is how I found out. Weatherproof and 2 fans blowing down, one up, to create a airflow inside the dome, and keeps everything sharp as a blade. You need only a few degrees more. Don't start heating up the fridge.

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#16

Re: CCTV Camera Fogging

09/11/2010 5:01 AM

Remove the gel pacs they at the temprature in question are just storing the moisture, so when heater is on the gel packs give up the moisture they have stored creating the problem

remove the gel packs, remove the heater, leave camera housing open for 2 hours for inside housing to cool down to ambient temp (ie the same as the freezer) then rplace dome screw back on wall and see more clearly

please report back on success of this for the Doubters

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#20
In reply to #16

Re: CCTV Camera Fogging

09/11/2010 10:30 AM

I'm throwing in with you on the idea of turning off the heater and removing the dome. I'm also thinking that the heater is kicking in at 14C not 14F as poster states; please check the specs on your camera and make sure it's F v. C. I installed a PTZ camera for a friend of mine in a walk-in which stored beer kegs on one side and kitchen perishables on the other, and we had the same fogging with the dome. It was a Panasonic PTZ system which the heater turned on at 10C (50F btw). The heater is definitely not meant to be a defogging device, it is to prevent freezing of the PTZ or any other moveable parts. Heating the camera with the dome on creates a temperature difference(TD) between the inside and outside...hence fogging. I mounted this camera where it gets a pretty could stream of air from evap fans and no problems at all.

Only other options I see would be to evacuate the dome completely with a vacuum, but that won't last long given nature's resistance to vacuum's here on earth, or go with a dessication unit like a Munter's system to drop the humidity down to near 10%(you may still fog up to to the TD with the heaters!). These are high cost to install and 2 or 3 times the cost to operate over the cost of your chiller, so the cost of beer is gonna' have to go up, or God forbid, drink less to save more!

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#25

Re: CCTV Camera Fogging

09/11/2010 9:57 PM

This is the back of a all weather PTZ camera print.

The 2 golden elements on top are the heaters, with between the fan that starts pushing the heat downwards.

See also the 2 other fans that work inverse.

If the temperature inside is a little higher than ouside, there can be no fogging.

Most non PTZ domes are a lot simpler and have no heating and/or circulation fan.

Just for your info. Good Luck

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