I am installing a small Class D amplifier in an outdoor weatherproof box on my detached porch ... outdoors (as much "weather" as we have here in San Diego).
The box is like this-
Amazon - Weatherproof junction box.
Box will be fully sealed only banana plugs and AC inlet on the outside, each fully sealed with whatever sealing gunk I have around here.
However when using the amp, the lid of the box will be open with small class D wifi amp exposed (can use via remote control).
So no venting needed for heat dissipation, everything will be open and exposed (its under a roof as well) when its being used.
When not in use the box will be closed and sealed up and also unplugged.
Question- do you have to worry about condensation inside a sealed box like this? Hot/cold/sun/shade? Need some kind of "purge" valve like Pelican uses on their cases? Wondering if a vent of some type is needed for the 2 months it will just sit there unused, or will actually have a undesired effect of letting in moisture?
The box is like this-
Amazon - Weatherproof junction box.
Box will be fully sealed only banana plugs and AC inlet on the outside, each fully sealed with whatever sealing gunk I have around here.
However when using the amp, the lid of the box will be open with small class D wifi amp exposed (can use via remote control).
So no venting needed for heat dissipation, everything will be open and exposed (its under a roof as well) when its being used.
When not in use the box will be closed and sealed up and also unplugged.
Question- do you have to worry about condensation inside a sealed box like this? Hot/cold/sun/shade? Need some kind of "purge" valve like Pelican uses on their cases? Wondering if a vent of some type is needed for the 2 months it will just sit there unused, or will actually have a undesired effect of letting in moisture?
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I was into HAM radio in college. I remember one of the professors quip regarding the "waterproof-ness" of enclosures used for RF preamps mounted on the antenna tower: "You can't make anything waterproof, so you might as well drill a drain hole". We used waterproof enclosures and had all openings in the box facing down and sealed with goop. Water still got in there.
Undoubtedly we now know more about how to make stuff leak proof, but still... I'd keep that in mind.
You could just run speaker wires in a conduit to the deck and have the amp inside the house.
Tom
Undoubtedly we now know more about how to make stuff leak proof, but still... I'd keep that in mind.
You could just run speaker wires in a conduit to the deck and have the amp inside the house.
Tom
Ha! Good point! While there are no side walls on the patio this is under a roof offset quite a bit so it is mostly protected. Condensation is what I'm worried about.
I've had a 50 inch LG tv out there for the last year with no issues but usually bring it in when it rains.
Conduit is not possible and even if it were it would be a pain to control everything from 50 feet away in the house.
I've had a 50 inch LG tv out there for the last year with no issues but usually bring it in when it rains.
Conduit is not possible and even if it were it would be a pain to control everything from 50 feet away in the house.
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To be fully hermetically sealed a box has to withstand changes in barometric pressure, so it needs to be strong. If its not hermetically sealed with dry air or nitrogen there will be condensation unless its permanently generating enough heat to prevent it. Conformal coating is pretty much a must for this kind of environment.
Pressure valve.
Here is an excellent technical paper on the topic- The Unknown Problem with Airtight Enclosures by WL Gore and Associates.
Even a very strong seal will break over time due to increased or decreased pressure, so the solution is to add a impermeable vent made of ePTFE (a special type of teflon that lets air through but not water) to equalize pressure.
These seals/vents, I have found, cannot be easily or cheaply purchased except for one application- they appear common for surfboard/ paddleboard vents.
Like this-
Alomejor Surfboard Vent Plastic Surfing Air Vent Breathable Stand Up Paddle Vent
Here is an excellent technical paper on the topic- The Unknown Problem with Airtight Enclosures by WL Gore and Associates.
Even a very strong seal will break over time due to increased or decreased pressure, so the solution is to add a impermeable vent made of ePTFE (a special type of teflon that lets air through but not water) to equalize pressure.
These seals/vents, I have found, cannot be easily or cheaply purchased except for one application- they appear common for surfboard/ paddleboard vents.
Like this-
Alomejor Surfboard Vent Plastic Surfing Air Vent Breathable Stand Up Paddle Vent
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I'd drill a couple of drain holes and give the PCBs some conformal coating.
Good thing you don't live in Seattle then.
I thought that's what kids were for. Or wifi. Whatever works.
You could turn it into a DIY project by implementing said wifi control if it doesn't exist already.
Tom
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