Oculus All Sky Camera and Dome - Condensation Problem

[PhotoGav]

 

As you can clearly see from this image, I have a condensation problem inside the dome of my Oculus All Sky Camera. After a particularly rainy period it invariably has condensation inside the acrylic dome. I cleaned the inside of the dome only two days ago, it poured yesterday and overnight and now I have condensation. I have the internal dew heater on a timer to come on at nighttime only every night. The camera lens is fine. The dome is not fine! It does evaporate eventually, but takes quite a while and obscures a clear view for the start of a night and beyond. 

Does anybody else with the Oculus suffer the same problem?

I am thinking of putting a couple of those small silica bags inside the dome to try and stop this happening. Do you think that is a good idea and will work?

[LightBucket]

Well, at the price they are, that should not happen...

Can you have the heater on all the time, on a low setting..and try that..?.usually condensation is cause by a lack of ventilation, and not the need for heat, so that would more likely be the issue..

[Peter Drew]

I've seen somewhere in the past that placing a block of aluminium inside the dome encourages the condensation to form on the block rather than on the dome. Could be worth a try.    ?

[PhotoGav]

26 minutes ago, LightBucket said:

Well, at the price they are, that should not happen...

Can you have the heater on all the time, on a low setting..and try that..?.usually condensation is cause by a lack of ventilation, and not the need for heat, so that would more likely be the issue..

Thanks @LightBucket. Exactly - for the price I was expecting perfect images and constant clear skies!

I used to have the heater on all the time in the past and changed to the nighttime only approach last winter to try and solve the condensation problem. Your point about ventilation could be the key... After the recent clean I closed the dome down as tight as possible to ‘seal’ it from the outside as much as possible. That could have been my fatal mistake. I have just read the Oculus manual and it talks about pads that maintain an air gap around the base of the dome! I have just cleaned the inside of the dome and have put it back together as loosely as possible to leave that air gap. I now want it to pour with rain to test, so hopefully we will all enjoy weeks of dry and clear conditions!!

 

12 minutes ago, Peter Drew said:

I've seen somewhere in the past that placing a block of aluminium inside the dome encourages the condensation to form on the block rather than on the dome. Could be worth a try.    ?

Thank you @Peter Drew - interesting idea that I will have to try if the new air gap approach fails. 

[steppenwolf]

I would be tempted to retro-fit a small circulation fan but surely SX should have thought of this issue? Peter's 'sacrificial' block seems like a worthwhile try as well. My own home made all sky camera doesn't suffer from this but then it isn't out all the time and I have designed the heater such that is give a natural circulation effect.

[PhotoGav]

5 minutes ago, steppenwolf said:

I would be tempted to retro-fit a small circulation fan but surely SX should have thought of this issue? Peter's 'sacrificial' block seems like a worthwhile try as well. My own home made all sky camera doesn't suffer from this but then it isn't out all the time and I have designed the heater such that is give a natural circulation effect.

Thanks Steve. I am hoping that SX had indeed thought of this issue, solved it and then dummy PhotoGav came along and purposefully disactivated their solution!! Only time and rain will tell...

[LightBucket]

6 hours ago, PhotoGav said:

Thanks @LightBucket. Exactly - for the price I was expecting perfect images and constant clear skies!

I used to have the heater on all the time in the past and changed to the nighttime only approach last winter to try and solve the condensation problem. Your point about ventilation could be the key... After the recent clean I closed the dome down as tight as possible to ‘seal’ it from the outside as much as possible. That could have been my fatal mistake. I have just read the Oculus manual and it talks about pads that maintain an air gap around the base of the dome! I have just cleaned the inside of the dome and have put it back together as loosely as possible to leave that air gap. I now want it to pour with rain to test, so hopefully we will all enjoy weeks of dry and clear conditions!!

 

Thank you @Peter Drew - interesting idea that I will have to try if the new air gap approach fails. 

That sounds like the issue, without a doubt...many people seem to think the answer to condensation is heat or a dehumidifier, but that’s just treating the symptoms, you need to get rid of the cause which is always lack of, or no ventilation..

I have a shed that’s watertight, but has gaps all over where the wood cladding has shrunk, the doors don’t fit properly and there are air gaps everywhere, yet my metal tools inside have never has a drop of condensation on,  or any rust whatsoever..what does that tell you...

[Whirlwind]

On ‎11‎/‎11‎/‎2018 at 12:19, PhotoGav said:

I used to have the heater on all the time in the past and changed to the nighttime only approach last winter to try and solve the condensation problem. Your point about ventilation could be the key... After the recent clean I closed the dome down as tight as possible to ‘seal’ it from the outside as much as possible. That could have been my fatal mistake. I have just read the Oculus manual and it talks about pads that maintain an air gap around the base of the dome! I have just cleaned the inside of the dome and have put it back together as loosely as possible to leave that air gap. I now want it to pour with rain to test, so hopefully we will all enjoy weeks of dry and clear conditions!!

 

I have the same camera, but don't get the same issue.  The outside will fog over after rain but not form condensation inside the way yours does (and its cleared after about an hour).

I leave my heater on permanently.  I would agree that it is likely a ventilation issue.  Regardless of how well you screw on the dome you won't have a perfect seal.  As such humidity will leach inside.  The lack of air flow will trap air generally however.  

What happens is this - the dome is exposed to daylight.  It acts as a greenhouse so the air inside warms up (even the dew heater can cause this slightly).  The dome is being cooled by the air outside and you will probably find it is 10C or more difference in the direct sunlight.  The dew heater is designed to keep the dome temperature slightly above the outside radiative temperature on a clear night.  So you have warm air inside, which holds more moisture.  The outside air cools the dome.  The dome is hence cooler than the inside ambient air and hence when the water molecules hit the dome they lose energy.  This will cause moisture to condense on the inside of the dome.  The reason for ventilation is that it means the air is the same temperature inside and outside.  The dome is therefore the same temperature.  Moisture will hence no longer condense onto the inside of the dome (indeed the dew heater keeps it slightly warmer) to help prevent this.

[Thalestris24]

If it's a sealed unit then desiccant should remove the moisture. A deluxe approach might be to purge the dome with dry gas - like they do with some cooled cameras. Just my 2 cents

Louise

[PhotoGav]

Thank you @Whirlwind and @Thalestris24 - I am hoping that the ventilation solution will be the winner. So far so good... it has rained here over the last 24 hours and the dome is perfectly dry inside. 

[Whirlwind]

11 hours ago, Thalestris24 said:

If it's a sealed unit then desiccant should remove the moisture. A deluxe approach might be to purge the dome with dry gas - like they do with some cooled cameras. Just my 2 cents

Louise

I'm not sure the seal is good enough as it stands to purge the environment.  The casing would probably need some significant changes to be able to effectively purge the atmosphere.  The dome is designed to be easily replaceable if it is scratched etc.

[Thalestris24]

1 hour ago, Whirlwind said:

I'm not sure the seal is good enough as it stands to purge the environment.  The casing would probably need some significant changes to be able to effectively purge the atmosphere.  The dome is designed to be easily replaceable if it is scratched etc.

Oh well, it was just an idea  

[PhotoGav]

I thought I would update this thread as I am delighted to report a successful solution has been supplied by Starlight Xpress. Terry at SX was very helpful and after discussion and various failed experiments he sent me a new base plate that has two 1 cm holes drilled in it. I swapped out the base plate and for once I was happy that it rained. The good news is that the dome no longer mists up inside. I’ve run it for the last few nights and it continues to work perfectly. So, ventilation was indeed the issue. Here’s a snap of the sky out there right now, a view that in the past would have been completely obscured by condensation...

And now I return to being irritated that it’s raining!!

[michaelmorris]

Very interesting and useful discussion. I think I may try adding a fan to my system.

[jam1e1]

Glad to hear - would you mind sharing a picture of the part, as I had exactly the same issue other night - reason not seen before is because ive not had out in rain previously, thought mine had leaked at first!

[michaelmorris]

On 09/02/2019 at 12:31, michaelmorris said:

Very interesting and useful discussion. I think I may try adding a fan to my system.

I've now added a 12 v fan and drilled some holes in the base of the enclosure and between the dome and enclosure and hey presto!, last night it was pretty clear and no condensation ?

[PhotoGav]

On 11/02/2019 at 21:46, jam1e1 said:

Glad to hear - would you mind sharing a picture of the part, as I had exactly the same issue other night - reason not seen before is because ive not had out in rain previously, thought mine had leaked at first!

Sorry, only just seen this post. I’ll put a picture up tomorrow. 

[jam1e1]

On 25/02/2019 at 23:15, PhotoGav said:

Sorry, only just seen this post. I’ll put a picture up tomorrow. 

thanks that would be great - just dont want to drill wrong place and end up ruining it

[PhotoGav]

47 minutes ago, jam1e1 said:

thanks that would be great - just dont want to drill wrong place and end up ruining it

It appears that ‘tomorrow never comes’....! Sorry, totally forgot, will put this on my To Do list and post a pic once storm Freya has wound down a bit!

[PhotoGav]

On 11/02/2019 at 21:46, jam1e1 said:

Glad to hear - would you mind sharing a picture of the part, as I had exactly the same issue other night - reason not seen before is because ive not had out in rain previously, thought mine had leaked at first!

Here's a picture of my Oculus's bottom:

I have a couple of small round gauzes from the Smokers Delight stand in the local market to cover the holes over to stop any small animal incursions! I will get round to putting them in place eventually, but it doesn't seem to be a spiders nest or similar yet...

[jam1e1]

thanks ill do same- so it was literally as brutal as that!!! ive never had issue before as never left mine out in rain until recently........i take down and put up each night used....planning on doing a semi perm fixing to house to make it easier. My only small concern is potential water ingress or longer term if don't have heater on every night...hope it works out ok, mine will have similar treatment soon!

[PhotoGav]

1 hour ago, jam1e1 said:

thanks ill do same- so it was literally as brutal as that!!! ive never had issue before as never left mine out in rain until recently........i take down and put up each night used....planning on doing a semi perm fixing to house to make it easier. My only small concern is potential water ingress or longer term if don't have heater on every night...hope it works out ok, mine will have similar treatment soon!

Yup, brutal, but efficient!