I have a chance in a few weeks to start looking into improving the ventilation system on my trailer (http://CounterMoon.org) and I was wondering how much interest the topic might have.

I remember RV ventilation mostly as "turn on the A/C or go outside", but isn't there a better way?  And do all ways have to be 110V or have no flow? Do all ventilation solutions have to be 'something we put up with'?

What I currently have is three muffin fans, known for their 100% duty cycle, long life, and a 5-bladed contruction to keep the noise down. They use very little power.  But they don't push a great deal of air, and I think I can make it quieter.

Here's the idea:

Let's get a squirrel-cage for the fan. Two plastic wheels, with ball-bearings in their center, and let's punch louvers into a sheet of aluminum for the blades.  This kind of thing, I think most folks can do with simple parts. Make the outside of similar, 1/4" thick plastic. Nothing to rust, no problems.

Add on an old friend: one of the electric motors from the R/C industry.

Have you seen these? These have taken ALL OF THE WORK from flying planes in school yards; just charge a battery when you get there (takes 15m) throw another on to charge while you fly, go home when ya like.  They're amazing, the strides they've made in these motors. No oil, not loud, everything nice an clean and easy.

My interest is in their reliability and effeciency. They're a little fast for a fan like this, and the motor controls required for it are a little expensive.  But consider this: you might make/buy one of these for the rest of your *life*. All the electronics are proven in the field for the last 30 years.

A squirrel-cage fan's the most effective way to get this done.  Cut a square in your floor somewhere and pipe it into your system. And if you're using an onboard computer system, you'll be able to ramp-up the speed slowly so no one notices it's on, and alternatively kick it on full-bore if you need to clear the cabin.

I'm not working with *ANY* vendor, just to be clear. This is just an idea, and as we draw nearer to the winter, this probably the wrong time to even bring it up.  But I'm curious- is anyone interested in better ventilation in their RV?

I have had this same topic on my mind the last little while, we have been doing some camping without land power and my cieling fans work only on hydro.  I like the air moving in the fiver and have been thinking of removing the one cieling fan in the kitchen and replacing it with a variable speed exhaust intake fan like the one that i have in the bedroom.

These work very well and one can slow down the intake or exhaust to a slow movement of air and also very quiet, not like the air condioner fan

Ya know, ceiling fans are something I never considered; my trailer's about 1/2" taller than me.  :)  But I do feel the need for the air, which I know is cooler, from the outside to cool the place from time to time.

The placement in the floor was considered because that's where the shadow always is. All kinds of filtration is possible; there's a lot of room outside, and some people have deep pockets enough to keep changing filters, so I never dealt with it.

The nice thing about this is that it comes up into a 'box canyon' of sorts. The air comes straight up, then hits a wall, diverting it just under my chair, making it more livable in the summer time. (And the direction was accidental.)  Pushing in the air has the effect of pressurizing the trailer ever-so-slightly, and the exhaust heat, mostly at the top, edges it's way to the big vent on top.

I could probably get some parts and invest the time, I'm just haven't decided, ya know?

We have two 12 volt Fantastic Fans http://www.fantasticvent.com/ that do a great job. They are reversible, thermostatically controlled and even close automatically if it rains. We put them on exhaust and open a few windows on the shady side.

Well I'm no fan (PTP) of re-inventing the wheel. But I had several fans in my overhead vent; they were pretty noisy, even large, flat blades (five of them). On a tangent; did you see the new fan type Dyson (the vacuum cleaner people) came up with, with no exposed blades? Google it; it's really cool. It looks like a hand mirror with no mirror. Yet, it's supposed to have quite the airflow and seemingly out of nowhere. About how much was your fan? I spent 10 minutes with websites that can't quite get it together, today...

Fantastic Fans are VERY quiet and they are multi speed also. Ours came with the Cameo, but I think they are about $250. There are less featured models, down to $90. We just replaced the helicopter fan in the bathroom with one last week.

I'm pretty sure these would be less. and operate at a 'random speed' so that the bearings don't begin to moan until they're actually dying.  I've just learned in my research that a 2400 RPM motor system, left at that speed, eventually will whine and wear. Putting a 'white noise generator' in as a speed control means it's never running the same *exact* speed, or speeds, and doesn't wear the bearings unnecessarily.  Interesting concept.

Even so, if I can't get something like this done for under $100, I'm not trying. Think a second: I can buy both a television set AND a microwave oven for less than $100. There's no reason it should be more than double that cost.

In my trailer, not only is the ceiling so low I can almost hit my head on it, but the overhead hole where a ventilation fan will go will likely be replaced by an A/C unit. I have to do something about the ventilator, eventually.

Maybe this is something only I'm gonna have interest in; we'll see.  Thanks for the info, though.

Here's an idea that's very power efficient, a little taxing with water supplies, but will cool you down quite nicely.... as long as you're in a dry enough climate.

-- Edited by DagoRanch on Thursday 15th of October 2009 10:25:15 PM

Actually, that's an alternate topic.  That's under my "Air Conditioning" project, which is at the site, too.

The current choices are to:

1. Come up with $900 because, like the $200 microwave oven, appliances that occur above axles MUST COST SO MUCH MORE.

2. Convert a NEW, $75 room airconditioner into it's component parts, use properly-chosen 12V fans in front of the coils and the 110V for the compressor. It's a fun project, completely do-able and perfect for HVAC newbies to sink their teeth into.

Right now my contact at the center's dropped the ball, I think he's confused that this might generate money, and isn't talking to me. I plan to start addressing actual humans this fall.

This one's just about ventilation- getting outside, fresh air into the cabin. So far, the old-style top-of-the-ceiling fan is the best available, and for some reason it's >$250. I'm pretty sure that, with highly precise and reliable products I can probably beat that by half.

Ah!  When you mentioned A/C in the first post, I thought you may be going for cooling as well.

Great luck with fantastic fans and we have a ceiling fan which is often used.

Larry and Jacki