4mo ago

if pure water is not conductive why would condensation be an issue for electronics?

I mean, it should be close to pure water, right? Why would some condensation short electronics?

12 comments

As others have said, corrosion.
To add to that, condensate is rarely pure water. At least, not by the time it’s chilling on the circuits. It’ll pick up any dust, and other stuff fairly quickly; making it not-pure. And conductive.
The water contributes to rust which is bad for electronics long term
Second, electrolytes on the surface of the electronics, bits of metal, dust, or whatever can enter the water and provide a pathway for electricity.
That's my guess anyway.
It's not pure. It's water from the air, which contains all sorts of crap. Especially if you smoke or have pets.
Causes corrosion.
Causes circuit boards to swell and deform.
- Yup, electronics tech here and we have to bake our boards to remove moisture from the mid-layers before conformal coating them. We do boards which go through pretty harsh conditions so moisture trapped in the boards could cause massive issues at sub zero temperature and swelling from evaporating liquids cause issues at high temperatures.
  Less of a concern for consumer tech but can be a huge concern at industry levels.
Water dissociates in the presence of electrical voltage into hydrogen and oxygen, and that makes it somewhat conductive (due to ionisation).
The bigger problem however is corrosion. Said oxygen causes corrosion.
Because it is really, really difficult to get pure water. Even distilled water isn't pure. I'm not even sure you can get pure water outside of an industrial or laboratory setting
- If you burn hydrogen and oxygen, you’ll get pure water, but you would need to store it immediately after the reaction. If you let the water sit in a bucket, it’s going to absorb all sorts of things from the air around it.
You rarely encounter pure water out in the world; even rainwater will have things dissolved in it.
Even then, there may be chemicals like solder flux or electrolyte from a leaky capacitor that water might dissolve and become conductive enough to cause problems.
Same reason why they use distilled water in water cooled computers
Because pure water isn't conductive while impure water is
It's the impurities in the water that conducts electricity
https://youtube.com/shorts/2dbTkVc0zkc
"pure water" is not what you think it is. It really doesn't exist outside of laboratory conditions.
Pure water is conductive, especially if you apply electrochemical potential. Look up autodissociation of water.

12 comments