Engine saver for an airframe?

[201Steve]

There are a bunch of folks here that are knowledgeable about this topic so I wanted to throw it out to the group for feedback.

As we all know, there are many devices designed to push dry air into our engines (Black Max, Engine Saver, etc.) to reduce a corrosion fertile environment.

I was thinking about this model, but for the airframe.

What are the chances you would help the bones of an airplane by taking an inline dehumidifier (one you can attach ducts to) and let’s just say, you put the intake and the exhaust ducts and run them through the pilot window. Create some type of plug, where it’s pulling air from the cabin, dehumidifying the air at the unit (outside the airplane) and then pushing dry air back into the cabin.

 

You could take that same concept and attach those fixtures to say, run inside the wing. Maybe use an inspection panel, and retrofit it to accept the ducts from the dehumidifier.

And then, theoretically, you could go with say the tail section, and maybe even have 3 locations simultaneiously (cabin, wings, tail) where it’s conditioning the air (dehumidifying).

 

Yes I know the wings, the cabin, and certainly the tail section are not air tight. But if you were forcing air into the confined area with enough volume, you just have some leakage, but it’s still being overwhelmed with much drier air.

 

Thoughts?

 

 

[N201MKTurbo]

Couldn't hurt.

If you have a hangar, just get a dehumidifier for the hangar. 

It will be difficult to get to all the spaces in a Mooney. You have the cabin, wings, tail cone, engine compartment, horizontal and vertical stabilizers and control surfaces. 

The best plan is to just move here, we don't have humidity. Just heat and UV. The UV will wreck the paint and interior, but the metal parts will last forever. 

[201Steve]

Well, I do have a hangar. It’s got rolling doors, not the best seal. Lots of volume. 2,000 sf. Seems like you could do more efficient work isolating your critical area.

I don’t know how well a dehumidifier would work in an area that big, without great sealing. I could probably do a lot to seal it up better, but how far must you go for success?

[00-Negative]

I put a cheap, Amazon dehumidifier hanging from the coat rack in my plane. The outlet tube runs into the tailcone and hangs above the opening for the retractable step. I just leave the tubing in place and connect the dehumidifier when I put the plane up. My hangar leaks through the roof and during periods of high rain volume water comes in under the walls and remains standing on the hangar floor for a few days. But I don't have any other hangar options and my cost is $60/month. The humidity in south Louisiana is 99% year-round. The dehumidified air inside the plane gets as low as 30%. I don't do anything for the wings/ fuselage. 

 

-David

[EricJ]

A good thing to do is just fly to a reasonable altitude once in a while.    It'll push most of the air out of the various spaces and inhale dry, high-altitude air as you descend.   Dries it out nicely.

[Fly Boomer]

6 hours ago, 201Steve said:

What are the chances you would help the bones of an airplane by taking an inline dehumidifier (one you can attach ducts to) and let’s just say, you put the intake and the exhaust ducts and run them through the pilot window. Create some type of plug, where it’s pulling air from the cabin, dehumidifying the air at the unit (outside the airplane) and then pushing dry air back into the cabin.

I have given some thought to using a system similar to your idea for just the engine.  By essentially "tenting" the engine area with a not-especially-tight seal around the cowl and where the tent meets the hangar floor, and then pumping enough dehumidified air into the tent to extract the moisture from every crevice of the engine.  For the engine, this avoids reconditioning crystals, hooking things up to intake, exhaust, oil filler, etc.  Similar to dehumidifying the hangar, but requires much less volume of dehumidified air.  No reason it wouldn't work for other parts of the airplane.  In fact, your idea might be easier to implement because the volumes you are proposing to dehumidify are already somewhat air tight.  Maybe instead of blowing in one orifice (like the storm window) and drawing out air from another, you could just blow dehumidified air in, and let the moisture-laden air leak out of all the small exit points.

[Will.iam]

My dehumidifier is for 4000sf and it was like $230 it would be the electric bill that would get high if your hanger leaked as it would force the dehumidifier to work more than normal. 

[Schllc]

I have often wondered if tenting the whole plane with a giant tarp and putting the dehumidifier inside would be effective. 

[Fly Boomer]

4 minutes ago, Schllc said:

I have often wondered if renting the whole plane with a giant tarp and putting the dehumidifier inside would be effective. 

That might be easier than tenting just the engine, or trying to isolate some part of the airframe.  That said, it would require a bigger tarp than I have ever seen.

[Ron McBride]

You can get heavy duty large tarps from tarp companies, similar to what trucking companies and fumigation companies use.  Maybe Mitch can chime in, I think he built something for Jolie’s plane to keep the dust etc. off.

[Schllc]

9 hours ago, Will.iam said:

My dehumidifier is for 4000sf and it was like $230 it would be the electric bill that would get high if your hanger leaked as it would force the dehumidifier to work more than normal. 

One thing I would point out is that cubic feet is more important than square feet. 
I would be willing to bet that most advertisements that use sqft are predicated on an average ceiling height of 8’. Our hangars are likely closer to double that volume, also no where near as tight as a house. I would figure you need 300% more for the same sqft to make any difference at all. 
In our hangars that would present a challenge because there is no where to pump the amount of water it would produce. 

[BlueSky247]

47 minutes ago, Schllc said:

I have often wondered if tenting the whole plane with a giant tarp and putting the dehumidifier inside would be effective. 

This is exactly what I was just going to say. People have those "car in a bubble" things for classic cars in their home garages.

 

It wouldn't be hard to imitate those home made spray paint booths that some people do as well. Just lots of 2x4s, plastic and duct tape. That would be the trick for those with leaky/drafty hangars. Then just park a console dehumidifier and oscillating fan under it/the plane. The condensate can just be routed out a drain tube under those leaky doors. 

[Fly Boomer]

11 minutes ago, Schllc said:

In our hangars that would present a challenge because there is no where to pump the amount of water it would produce.

I imagined positioning the dehumidifier near the big door, and the water would just run under the door,

[Schllc]

6 hours ago, Fly Boomer said:

I imagined positioning the dehumidifier near the big door, and the water would just run under the door,

My particular hangar is asphalt on all four sides. The only place I could put it would be on the north side which would make a mess because as much water as it would produce it would never dry…

[201Steve]

6 hours ago, Schllc said:

I have often wondered if tenting the whole plane with a giant tarp and putting the dehumidifier inside would be effective. 

That is where I started with my thinking. It would be a hideous addition to my otherwise v nice hangar, but to either build a PVC enclosure, or have like a drop tarp actuated by pulleys up top, weighted edges to hold a decent seal against the floor, with a dehumidifier underneath the airplane and thus, inside the containment area. 

 

On 9/18/2024 at 2:49 PM, EricJ said:

A good thing to do is just fly to a reasonable altitude once in a while.    It'll push most of the air out of the various spaces and inhale dry, high-altitude air as you descend.   Dries it out nicely.

Eric… you live in AZ (I think). You know nothing of the moisture laden air of the southeastern United States. Hahahah. 

[Will.iam]

Most of my neighbors have insulated hangers and eventually i will just foam my hanger then put a mini split a/c a 24,000btu system can be had for $1,400 and will cool 1250sf you dont need it to cool down alot. Just 10 degrees difference will lower the humidity in the hanger to keep corrosion at bay. Figure $4000 for foam insulation (don’t need think just enough to seal off all the drafts so $5,500 you could keep corrosion and critters out of your plane, in the grand scheme of expenses not much for whole aircraft protection.