Again 2 box fans setup on angles across the car but not into each other running 24/7 will prevent this. I have had my car for 2 years with bare cast iron parts the look like the day they were installed because of the moving air provided by cheap $10 box fans.

 

I prefer the Car Jacket,for indoor use.

http://www.autoanything.com/car-covers/69A1798A0A0.aspx
It comes with 10 desiccant packets.

After zipping it up an ant can't get in. My 71 has been inside these jackets for somewhere near 8 years and keeps it dry and protected!

WB

 

The first guy who can change the laws of physics so that a partial vacuum causes moisture to evaporate.

 

what laws of physics? the flash point of water is at a lower temperature at low pressure than it is at high pressure.. liquid water will outgas ( or boil) quicker the lower the pressure, given the same temperature. so a partial vacumm does cause moisture to evaporate quicker..

these car inflatable bubbles are actually the opposite, there is higher pressure inside where the car is, causing moisture to condense inside the bubble at a temperature that it would not condense outside the bubble.

 

I'm not too sure about Joewill's "flash point", but I generally agree with the rest of his post. My understanding of the Newtonian physics of the situation is that the driving force for evaporation is the difference between the vapor pressure of the water and the partial pressure of the water in the surrounding atmosphere. The vapor pressure of the water is dependent on temperature, so that at a given temperature, we can vary the driving force for evaporation by changing the partial pressure of the water in the surrounding atmosphere and possibly (more later) change the evaporation rate. Let's just say for a minute that we are at a temperature where the vapor pressure of water is .1 atm. If my atmosphere is 1% water, my partial pressure of water is .01 atm so my driving force is .09 atm. If I pull a partial vacuum so that the total pressure is .5 atm without changing mixture, my partial pressure becomes .005 atm and my driving force becomes .095.

So, in fact, we have increased our driving force by a whopping 5.6%. Whether or not this will increase the evaporation rate is dependent on the environment, more specifically, the availability of heat. Whether we are boiling water in a pot or drying clothes on a line, we need to get the 1000 or so BTU/lb heat of vaporization from somewhere to get the water to evaporate. In a cool garage, often the rate limiting facet of the situation is the availability of heat, and if this is the case, then increasing the driving force 5% will have a minimal, and possibly no, effect. It also bears noting that we pulled a 50% vacuum to get a 5% increase in evaporative driving force.

All that said, while I disagree with what Mike said about the physics involved, I think that functionally, it's a **** poor way to try to keep your car dry in the winter.

 

If moisture is the big concern, get a bubble and throw in a big sack of dessicant when you seal it up.

Alternatively, get an Air Chamber and put an electric light inside with the car and leave it on. The chamber is freestanding with three openings (sides and back) so is easy to put stuff in (other than the car). We used to leave a light on in our boat when it was moored in the ocean and this keeps down the interior moisture and keeps things from rusting. If it works on boats moored in the ocean, it should work in your garage.

 

Aside from the fact that the difference in absolute pressure from inside the bubble to outside is almost too small to measure, the act of sealing a car (or anything) inside a 'vacuum bag' will simply trap the moisture inside. It doesn't magically disappear into the ether. Nothing is gained.

If the goal is to avoid corrosion, put the car in an environment with low humidity and stable temperature. These car bubble things achieve neither.

Edit: I see the confusion. I used the word 'evaporate' in my post above. Obviously this was the wrong word. Ooops.

 

I don't know how much air actually moves through the bubble for the purpose of keeping it inflated verses the fresh air factor but I would think if you limited the intake and then took that intake air from your air conditioned house you could end up with a decent bubble environment without breaking the bank. Seems like it would be cheaper than air conditioning the entire garage. Just a thought.

 

The concept of vacuum storage isn't difficult, it does work and it is not magic.
The magic is just a lack of understanding.

Vacuum removes the OXYGEN and some moisture with it which is part of the vapor content (air).

Almost impossible for rust and mold and fungus to grow without oxygen, even if some moisture in the form of humidity is present.

BTW, you can completely "boil out" water in a vacuum, but it occurs around 1500 microns, air powered vacuum pumps used in a/c work cannot even do that. You could store the car in a vacuum chamber similar to hyperbaric chamber construction, simply because it is very difficult to maintain a vacuum.

BTW, I stored a car, virtually untouched, in a barn, for 32 years straight, subject to extreme temps from 90° to below 0° and all types of humidity, with no adverse effects.

To the OP
Your prime source of rust is probably just the salt air. Find a good deal on storage further inland. Put a 50# bag of rice in it for moisture.
Air conditioned space is by far the best, but the air has to be returned to the unit for the moisture to be removed.

 

Not to beat this poor thing to death (ooops, too late ) but you're simply reducing the total volume of air trapped inside the bubble, not selectively removing oxygen, moisture or any other component in the mix. Mold and corrosion can still form according to what got trapped.

An effective method (and something I put into practice when I was responsible for the safe long and short term storage of over 1,000 gas turbine aircraft engines) is to hermetically seal the object in a heavy duty poly bag with a large amount of dessicant bags distributed throughout. An object the size of a refrigerator would require around 2 lbs of dessicant to do a decent long term job, so a car would take possibly 10 lbs. A telltale indicator can be placed inside to show if the moisture level is low enough. Generally, <40% relative humidity is a safe level.

To get back to the original topic, the blower equipped bubbles still defy logic if low humidity is the goal.

 

Thanks everybody for all the input... A/C in the garage is not really an option for me, could prob pipe in the air, but no way to run a return. Not to mention the garage is 3/4 the size of my house sq footage, so not buying a larger A/C... (rather spend that $$$ on a 5 speed and new seats) Thinking maybe some type of rigid "mini garage" I have a portable de-humidifier in the back of a closet somewhere that will shut off at a preset level, so that might be the way to go; drive in, turn on the de-humidifier and seal it up. Electric for the relatively short time it'll be running to drop the r/humidity would probably be cheaper than the desiccant.