Author Topic: Can AC be run as just a vent fan?  (Read 345 times)

Offline Aaarrghh

  • *
  • Posts: 132
  • Member since: 2016
  • I own: a Motor Home
  • Year: 1984
  • Make: Winnebago
  • Model: Warrior
  • Chassis: Chevy P-20
  • Engine: 350cid
Can AC be run as just a vent fan?
« on: May 13, 2019, 11:07 AM »
My Fantastic vent fan has stopped. It has done a good job of removing the hot air that accumulates below the ceiling. I might be able to fix it, but if it needs replacing, then the time may have come to get a roof AC. I'm looking at ads for the Coleman Mach 8 Cub, 9.2Kbtu model, which should be all I'd need for this small rig. But I don't know a thing about roof AC, having never had one. I do know they won't run on 12 volts, except swamp coolers, which would be useless in Florida where I spend most of my time.

I don't have a genny (no place to carry one, either), and most of the time I only have 12 volts from the solar and batteries. Will I lose the 12v vent fan capability when there's no 110v volts available, if I install an AC? I only have the one hole in my roof, and no space for another.

Is there an AC unit that will operate just as a vent fan, on straight 12 volts, or maybe off an inverter?

Offline Berlin-Tioga

  • *
  • Posts: 40
  • Member since: 2017
  • I own: a Motor Home
  • Year: 1979
  • Make: Fleetwood
  • Model: Tioga
  • Chassis: Dodge MB400
  • Engine: 440
Re: Can AC be run as just a vent fan?
« Reply #1 on: May 13, 2019, 01:18 PM »
Hi!


I had an old coleman AC on the roof and removed it las summer.
My reasons were:
- only used it twice, mostly because it was tooooo loud!
- it was darn heavy and way up, an I guess it influenced the drivability. Center over gravity an so.
- it wanted to use the hole in the roof for a crystal clear roof hatch.
That added so much more light! I don't regret that decision at all.
But then again I use that RV in central to southern Europe, which is probably not comparable to Florida ...


Just my 2 Cents.




Greetings from Berlin,
Ben


Offline Rickf1985

  • *
  • Posts: 5540
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1989
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Chevy
  • Engine: 454
Re: Can AC be run as just a vent fan?
« Reply #2 on: May 13, 2019, 01:49 PM »
You are not going to power any standard A/C unit from an inverter, the best of the A/C's draw around 9-11 amps on 110 volts so multiply that times a factor of 10.5 and that will get you in the ballpark of the amount of amps you will be pulling out of the batteries. Roughly 160 amps while the unit is running. That would kill the batteries in less than an hour. There is no outside venting on those units that I know of even on 110 volts. If you do not have access to a generator or power then you are stuck with a new vent fan.

Online TerryH

  • Full-time Adventurer!
  • *
  • Posts: 748
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1992
  • Make: Winnebago
  • Model: Brave 27RC
  • Chassis: GMC P30
  • Engine: 454 Dual Fuel
Re: Can AC be run as just a vent fan?
« Reply #3 on: May 13, 2019, 02:17 PM »
As well, a roof top 110V a/c would require all new wiring from the unit to the power source.
You would also have to determine if your roof would support the weight.
There are parts and upgrades available for Fantastic Fans available direct from Dometic and from secondary suppliers.
Fantastic used to have  excellent support for their products. Definitely gone downhill since Dometic acquired them.
If it did a satisfactory job until now, your best and least costly alternative may be repair.
Only those who will risk going too far can possibly find out how far one can go
T.S. Eliot   1888 - 1965

Offline Aaarrghh

  • *
  • Posts: 132
  • Member since: 2016
  • I own: a Motor Home
  • Year: 1984
  • Make: Winnebago
  • Model: Warrior
  • Chassis: Chevy P-20
  • Engine: 350cid
Re: Can AC be run as just a vent fan?
« Reply #4 on: May 13, 2019, 05:49 PM »
There is no outside venting on those units that I know of even on 110 volts.
Thanks, Rick.  That surely does answer my question.
I think I'll look at swamp coolers, though. I seem to remember reading about one that operated on 12v. One might be partially effective, even in Florida humidity. Even with the Fantastic drawing out hot air, the inside of the 'bago gets awfully hot. A little cool air coming in would be appreciated.

Online joanfenn

  • 7 year member
  • *
  • Posts: 570
  • Member since: 2011
  • I own: a Motor Home
  • Year: 1987
  • Make: Citation
  • Model: Excella
  • Chassis: GMC
  • Engine: 454
Re: Can AC be run as just a vent fan?
« Reply #5 on: May 13, 2019, 05:56 PM »
Just checked pinterest.  A ton of swamp cooler info on there even some using solar energy.  Might have to check it out also but like the fantastic fans in our trailer. :)

Offline Aaarrghh

  • *
  • Posts: 132
  • Member since: 2016
  • I own: a Motor Home
  • Year: 1984
  • Make: Winnebago
  • Model: Warrior
  • Chassis: Chevy P-20
  • Engine: 350cid
Re: Can AC be run as just a vent fan?
« Reply #6 on: May 13, 2019, 06:00 PM »
Hi!
I had an old coleman AC on the roof and removed it las summer.
My reasons were:
- only used it twice, mostly because it was tooooo loud!
- it was darn heavy and way up, an I guess it influenced the drivability. Center over gravity an so.
- it wanted to use the hole in the roof for a crystal clear roof hatch.
That added so much more light! I don't regret that decision at all.
Thanks for the tips, Ben. As I mostly boondock, my experience might turn out to be similar to yours, if I did install a Coleman or other AC unit. It would be a big waste of money if I only used it a little.

Offline Aaarrghh

  • *
  • Posts: 132
  • Member since: 2016
  • I own: a Motor Home
  • Year: 1984
  • Make: Winnebago
  • Model: Warrior
  • Chassis: Chevy P-20
  • Engine: 350cid
Re: Can AC be run as just a vent fan?
« Reply #7 on: May 13, 2019, 06:22 PM »
If I want to talk about a swamp cooler, I think I should start a new threat, eh? So that's what I'll do.

Offline ClydesdaleKevin

  • 11 year member
  • *
  • Posts: 4321
  • Member since: 2005
  • I own: a Motor Home
  • Year: 1995
  • Make: Itasca
  • Model: Suncruiser 32RQ
  • Chassis: Oshkosh
  • Engine: Cummings Turbo Diesel
Re: Can AC be run as just a vent fan?
« Reply #8 on: May 14, 2019, 09:34 AM »
Almost all issues with Fantastik fans is a bad or loose ground wire...usually at the cutoff switch if yours has one, that shuts the fan down when the hatch is closed.

Also, you can buy just the fan unit (the plastic blades and motor) for a LOT cheaper than buying a whole new unit, and it is way easier to install. 

And check the built in fuse.

Voice of experience here...lol!

Kev
Kev and Patti, the furry kids, our 98 Cherokee lifted beastie tow vehicle, and our 1995 Itasca Suncruiser Diesel Pusher.

Offline Aaarrghh

  • *
  • Posts: 132
  • Member since: 2016
  • I own: a Motor Home
  • Year: 1984
  • Make: Winnebago
  • Model: Warrior
  • Chassis: Chevy P-20
  • Engine: 350cid
Re: Can AC be run as just a vent fan?
« Reply #9 on: May 14, 2019, 12:37 PM »
Almost all issues with Fantastik fans is a bad or loose ground wire...usually at the cutoff switch if yours has one, that shuts the fan down when the hatch is closed.

Also, you can buy just the fan unit (the plastic blades and motor) for a LOT cheaper than buying a whole new unit, and it is way easier to install. 

And check the built in fuse.

Voice of experience here...lol!

Kev
Aye, this happened to me once before. The cure was the connections to the fan motor. I won't do anything more until I can get ahold of a tall stepladder so I can get up there and get at them, again. I've checked everything I can from inside. There's power to the unit, and the lid raises and lowers automatically as it should, but the fan just doesn't turn—either way. When this all started, the fan was erratic, sometimes it would go, sometimes it would stop on its own, then, as now, it would't go at all.

 

FULL Membership!

Want to start enjoyingall the benefitsFull Membership has to offer?

Become a Full

Want to enjoy your

Full Membership

without ever having

to renew?

Become a:

* Salvage Yards

Find
RV Salvage Yards



By STATE

* Resources

Need parts and information?
View the Resource List
.