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Discussion Starter · #1 ·
Hi,

I looked into installing a typical rv exhaust fan. They all cost a small fortune. I decided to try a less expensive solution.

The following applies to a 21RS.

1. Remove the screws holding the handles and then the four screws holding up the plastic inserts inside both vents, you will have to unscrew the ceiling switch for the bath fan too. Find the power connections for the exhaust fan in the bathroom ceiling.

2. Use a wire hanger to fish wires to the main vent. Make sure the power for the bathroom fan is off. Connect the wires in to the power using the existing twist connectors.

3. Purchase a three position DPDT toggle switch and 2 or 4 12volt computer case exhaust fans along with mounting screws for them. Look for the ones that use the least power and are the quiet. I choose two that use 2.4 watts each and move about 50 cfm each. More typical fans will move 25cfm and use 1.5watts. Make sure they are single speed fans. At a local electronics supply store in Montreal 25cfm fans sell for $10Can, the two I used cost $16 each.

4. Connect the power to the switch as follows:

1 2 3
4 5 6

connect pins 1 and 3
connect pins 2 and 5 to the black power wire
connect one half the fans to pin 4 (you probably want to use the red fan wire)
using the same color fan wire as in the previous step, connect the other half of the fans to pin 1 or 3

connect the black wires from all the fans to the *********** wire (I could have this backwards - I am working from memory).

Double check for shorts. Put the toggle switch into the center position, then switch on the power to the fans (bathroom switch).

Check that the fans all run as expected (bathroom switch works, one toggle position powers half the new fans, the other all new fans). If not, the while and black power wires probably need to be reversed.

Once it all works solder the connections at the switch (optionally use twist connectors to connect the fans and power for easy disconnection).

5. on the beam supporting the crank mark the positions for the screw holes for the fans. Use a small bit and drill pilot holes. Enlarge the holed to fit the fan mounting screws with a larger bit. There is an arrow on fans to indicate the direction the air flows. Screw the fans inplace on the beam using two screws per fan and lock washers. Remember to respect the arrows.

6. Test again. Mount the switch in the same place as the switch for the bathroom fan. Protect the connections on the top of the switch with silicon.

7. close up

Time will tell if the two screws holding the fans will be strong enough, I figured I would try the simplest solution first.

Running both fans here will use about 0.4 amps. I have two 75 amp hour batteries. Running the fans 100% of the time for 24 hours would use about 10 amp hours.

Bottom line. About $45Can and two hours for a 100cfm exhaust.

Comments?
Ed
 

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Great alternative idea. I still think I need a MaxxAir fan, since my OUTBACK stove doesn't vent outside. A fan that pulls in/pushes out more airflow would be just the ticket for me.

The Maxx:
High speed: 900 CFM at 4 amps
Medium speed: 680 CFM at 2.45 amps
Low speed: 500 CFM at 1.4 amps

Comes at a much higher price though...about $180!
 

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NDJollyMon,

If I read this right, the stock (admittedly wimpy) fan moved 25 cfm of air and these MaxxAir vents move 900 cfm? Holy smokes, that is a serious upgrade.

As long as it doesn't sound like a jet engine, that would be great for airing things out.

Chet.
 

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That is a lot of CFM. I'm pretty sure I'll be getting one. The actually sit outside the RV, so maybe it will be a little quieter!
 

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Discussion Starter · #5 ·
Hi,

The way I figure it there are about 1000cf of air in a 21rs. At 100cfm I exchange it all in about 10 mins. I figure if I turn on the bathroom fan too it will take less than five... Since the times I will really want to use the fan will be when there is no AC connection, low amperage is important.

In the 21rs case, I wonder if a maxair will fit. Might it not hit the AC if mounted on the main vent?

As for cooking. Look at the specs for the microwave, it you are really worried about it not exhausting to outside, change its setup. I have come across on outback that had this done. There was an exhaust beside the door. The owner was happy with the results. In my case I just cook outside if its something 'messy'.

Ed
 

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Ed,

Do I understand right that your 21rs has a roof vent other than in the bath? Mine is an '03 and only has one in the bath. I am thinking of venting the microwave outside and putting a maxxair or fantasticfan in the bath. The other plan I had is to install another vent in the roof in the living area and use a fantasticfan or maxxair vent. If yours has a vent in the living space, what is the location? If I go that route, I need to work around the a/c vents and roof trusses.

thanks,

Mike
 

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Ed sounds like you've come up with a good mod for your camper! Any photos of the setup by chance?

JollyMon. Best price I've found on the TurboMaxx is from Campers Choice for about $171 w/out the thermostat. If you sign up to get their catalog you'll also get a $10 voucher for your first purchase, add the extra shipping and you'll be around $174, but they don't charge sales tax. Have you found any better prices?
 

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Y...
That's about the cheapest I've seen. Now...if you could just mail me a check, I'll get this thing going!
 

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Discussion Starter · #9 ·
Mike

My 21rs has a vent in the bathroom and a second vent in the living area hall between the sink and stove.

Ed
 
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