I hate it when this happens...

[Piper J3]

I went out to the airplane yesterday to begin condition inspection. Weather was warm with rain in northern Ohio. I opened the hanger door and it looked like a rain forest. Airplane was soaking wet from condensation. I hate it when this happens and it seems to be more often with climate warming…

I can only imagine what is going on behind the scenes…. Inside of wings, fuselage, and stabilizes are most likely drenched with water. Engine I’m sure is soaked, but crankcase is closed to ventilation, so probably OK. What really bothers me the most is the instruments. Dual Dynon EFIS, transponder, comm radio, ADS-B transceiver, two iPads, intercom, ELT…. All soaking wet inside from condensation.

Then overnight, the temp dropped to freezing. I’m trying to put this episode out of my mind and will wait until spring to bring airplane back to life…
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[bkervaski]

Pretty normal for us southern states ... just about any early morning in the spring it's like this ... but I've never noticed condensation inside the cockpit or on the instruments

Typically it's just collecting on the outside surfaces, do you keep your cockpit closed or open?

[Kyle Boatright]

When warm, moist air meets a cold soaked airplane in a hangar…

[DennisRhodes]

Maybe a heat blanket or other source of heat inside the cabin could minimize this? Especially for instrumentation. Or better yet an outside the cabin heat source with duct routed to the inside. That's a lot of condensation.

[MacCool]

Keeping the air around the engine and in the cockpit above the dew point would seem to be a wise thing if such a thing happens a lot. I have the same thing happen in my boat's engine compartment and cockpit in the spring when we get those kind of temperature swings. The most prominent result in my case would be mold. Engine corrosion would be a secondary concern, although that seems like a more pressing problem in an airplane. I do keep my airplane hooked up to a circulating dehydrator 24/7/365 when in the hangar.

I solved that problem with my boats years ago by using a couple of cockpit fans during the winter and spring. There are a variety of models, and they're pretty cheap. They only run about 75-100 watts...it doesn't take much power to just keep the temps above the dew point. You could accomplish the same thing with a 100 watt light bulb on a drop cord, although I think the attached circulating fan makes those dedicated heaters a better device.

https://www.amazon.com/Caframo-Limit...DKIKX0DER&th=1

[Piper J3]

Canopy is closed when airplane is in hanger. I’m thinking about adding a small (150W 12V) space heater inside the cabin to be controlled with a humidity switch. Space heater and humidity switch would be located in closed cabin – both low voltage DC for safety.

Anybody doing this?
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[DanH]

Common down here. The airplane gets cold when winter air comes from the NW, then we get warm wet air off the Gulf. The fix is an ordinary box fan left running in the hangar. With air circulation, the surface temperature of the airplane remains close to the air temperature at any given moment....no condensation.

[subpar_bucker]

The weather in western PA has inspired a paint idea. Rat rod maybe?

[greghughespdx]

Remember, heating the air also increases its capacity to hold moisture, so when it gets a little colder...

A dehumidifier (larger one, which either needs to have a drain tube run outside, or needs to be emptied regularly) has helped in many cases. I have a similar hangar that would do the same thing at times.

And like Dan said, the box fan thing is for sure useful. That's what I do in my (current) hangar. Searching Amazon for something like "24 in. High Velocity Shop Fan" will bring up many options if you want to *really* move some air and have it be a (fairly) portable unit.

[Ron B.]

Any of you ever install a roof barn vent. I have a none heated equipment building that was doing the same thing. This building use to have an oil furnace thus the ss chimney to installed a barn vent( one that the wind turns). I leave a small opening on the opposite end of the building from the roof vent and I find a big difference with condensation. I think that as the outside temperatures change the roof vent brings the inside temperature quicker to the same as the outside temperature. Temperature equalizes and reduces condensation.
Worked for me.