Installing a ceiling vent where there is none..

[Cornbread Red]

Hi all,
My B has only a dinky "Fume Releaser" vent above the loo in the back. Living in Ten-Zillion degree Arizona, where temps inside a car hit 170F. in the Summer, I'm thinking that installing a 14" square (industry standard) vent like a Shurflo or Fantastic would be a good idea.

I have the tools needed, and am not "skeered" of cutting the hole. Right now, I'm thinking of mounting the vent right in line with the aft end of the cab-over, and in front of the air conditioner..

Being ah..er, "po",, I am aiming to spend as little as necessary to get the vent parts.. eBay is my friend.

Right now, I'm thinking of using a vent and adding a solar-powered fan unit in the vent top that can be on when the RV is not in use. The regular, larger 12V fan (reverseable) can be used when camping. I may mount the solar fan in a MaxxAir cover.

This project won't take place until the Fall, so if you see this post late, please don't think it's 205 to chime in. I appreciate any tips on vent units to use, installation, or links to suitable products. I'm especially interested in anyone's experience with the solar vent fans on the market.

Thanks.
Chip

[markopolo]

Take a look at MaxxAir

http://www.maxxair.com/products/MaxxFan.aspx

I had a Fan-Tastic Vent http://www.fantasticvent.com in my Roadtrek. I'm sure they're a great fan. They really stand behind the product and mine worked perfectly, but...................

I really like the MaxxAir I installed in my B+





I don't think I closed the vent all summer! Rain doesn't get in. They can be thermostatically controlled to help conserve power. I have a second vent on my roof so the windows can all be closed and I can still run the fan.

Provides over 900 CFM of airflow on High using 4.2 amps, medium one 617 CFM at 1.84 amps, medium two 730 CFM at 2.53 amps, and 500 CFM on Low at 1.45 amps

1.45 amps (on low setting) is less current than what a single 1156 incandescent RV light bulb draws.

I've seen them on sale at Camping World at about half what I paid for mine. I couldn't wait so I bought locally.

I don't have any comments to make re: solar vents - I've never had one.

My install was easy because I was replacing a (cheap) vent. The hole was there and the wiring was already in place. You'll have to run wire to your new install. That may influence where you end up putting it.

[markopolo]

Re: installation - the local dealer explained how to install the fan and gave me a roll of butyl rubber tape



I laid out the butyl around the 14" sq opening in the roof to form a gasket. The fan fastens to the roof with screws (lots of screws - maybe 20). As you tighten the screws some butyl will get squeezed out. I trimmed off the excess butyl and then used Dicor lap sealant around the perimeter edge of the fan housing and covered the screws. Dicor lap sealant is self-leveling so it makes for a nice finish.

http://www.dicor.com/



http://www.dicor.com/installcomp.html

[Cornbread Red]

Mark, you rock.

I think this is the solution, and especially for the low current draw.
Thank you.
Chip

[obiewan kanobe]

say cornbread......

i have a falcon b, cousin to horizon b. i'm gettin' old, but, i think i read somewhere that they used some sort of braces to support the fiberglass roof. i may be mistaken. i'm sure you dont want to cut through a support.

the people that build the present phoenix campers included some people that worked for intervec, the horizon builder. they have a website and club for class b users. someone there could give you the information you need to safely position your vent.

happy trails

[K-mann]

Would you recommend the butyl over the foam gasket that Fantastic supplies with their fans?

Also for sealing fridge side vents (service door / vent and upper side vent) would you use butyl / dicor combo as well?

[markopolo]

I'd go with whatever was supplied by or recommended by Fantastic when installing one of their fans.

I've never installed a fridge so I won't be much help to you. I would think the butyl rubber would work but try to find out if it is affected by by the heat from the fridge.

As much as I like Dicor I doubt that I'd use it around the sides of service door vent and upper side vent. It wouldn't look clean enough.

It looked to me that my Roadtrek had a clear silicone type caulk around the sides of service door vent and upper side vent. Same thing on my Trail-lite. The caulk around the sides of service door vent frame is clear and "rubber like".

[K-mann]

I ended up using RTV silicone sealant around the fan and it leaked. Of course we had a monster of a storm with high winds and driving rain, but it RTV silicone didn't hold up. I don't seem to have good luck with silicone sealants.
I dug out all the silicone around the edge of the vent and replaced it with this epoxy stuff that you mix and it hardens like steel. Maybe no the best solution if I ever want to remove the vent, but I'd rather cross that bridge when it comes than deal with a leaky roof. Of course I didn't use the stuff on the screws so I don't know if my leaks will stop or not. I think I'll just dump more silicone on the screw heads and hope that works. No rain after using the epoxy so I'm in wait mode.