Fantastic vent fan modification to stop vibration

jls · 03-03-2022, 09:56 PM

I have a Fantastic vent fan 6300 or 7300 which works fine but is incredibly annoying while driving... The wind will cause the plastic cover to vibrate pretty much non-stop. I can hand-crank the closing gear a bit tighter but it doesn't stop the noise entirely.

Upon closer inspection, the unit is made with a single flimsy bracket arm on one side and it is the other side that is free to vibrate. I added a small 1" bit of weatherstrip padding to that corner in order to mitigate the most clacky part of the sound but i'm wondering if anyone has a better solution to completely stop the vibration while driving?

There is a bug screen on the interior which limits my being able to access the cover from inside in order to add some kind of velcro or something temporary to hold it in place but maybe you all have another idea for me?

thanks!

folivier · 03-03-2022, 10:45 PM

I'd add a cover over the vent opening, Fantastic Fan makes a very good one and there are other brands that should fit.
It also allows you to open the vent while you're driving and also while it's raining.
The only negative is it sticks above the roofline.
https://www.amazon.com/Fan-Tastic-Ve...s%2C162&sr=8-2

avanti · 03-03-2022, 10:52 PM

I have owned two different rigs with Fantastic Vents. Neither of them has ever had a hint of the problem you describe. I think something is wrong.

You are not missing the big lid gasket, are you?

GallenH · 03-04-2022, 01:06 AM

The only problem I had is that high winds tore the cover off. Bought replacement and it fit perfectly...except....the track that holds the lid riser was too big. Riser arm kept coming out. Fixed with a washer and screw. Except for that, no issues even in high winds.

When you crank it all the way closed and check it on the roof, is there play that is causing the rattling?

jls · 03-04-2022, 01:29 AM

Quote:

Originally Posted by folivier

I'd add a cover over the vent opening, Fantastic Fan makes a very good one and there are other brands that should fit.
It also allows you to open the vent while you're driving and also while it's raining.
The only negative is it sticks above the roofline.
https://www.amazon.com/Fan-Tastic-Ve...s%2C162&sr=8-2

Thank you for sharing that! It might be a gasket issue, but if that doesn't solve the clacky noise then the cover seems like a good solution.

jls · 03-04-2022, 01:30 AM

Quote:

Originally Posted by avanti

I have owned two different rigs with Fantastic Vents. Neither of them has ever had a hint of the problem you describe. I think something is wrong.

You are not missing the big lid gasket, are you?

Hmmm..... gasket? I don't think there is one. The plastic lid that opens and closes and keeps rain out comes down onto a plastic opening (i think... i will double check that in the morning). It sounds like from your message there should be a gasket around the lip of that opening?

jls · 03-04-2022, 01:33 AM

Quote:

Originally Posted by GallenH

The only problem I had is that high winds tore the cover off. Bought replacement and it fit perfectly...except....the track that holds the lid riser was too big. Riser arm kept coming out. Fixed with a washer and screw. Except for that, no issues even in high winds.

When you crank it all the way closed and check it on the roof, is there play that is causing the rattling?

Yes, there is some play... maybe 1/8 to 1/4" of being able to wiggle the corner of the cover that doesn't have the side hinge. The hinge itself is tight, as are the gears, but there is just play in the plastic cover from corner to corner. This catches air movement as I drive, and when it's windy it is even more noisy.

avanti · 03-04-2022, 01:48 AM

Quote:

Originally Posted by jls

Hmmm..... gasket? I don't think there is one. The plastic lid that opens and closes and keeps rain out comes down onto a plastic opening (i think... i will double check that in the morning). It sounds like from your message there should be a gasket around the lip of that opening?

See part "C" in the below diagram:

RTRCMkU0RDUzQ0M1ODE3RDgxMDg6NWNmNjQ0ZGI0ZTEzNmMyY2U2YjUyNGY0ZWZkOTIzMDI6Ojo6OjA=.jpeg

jls · 03-04-2022, 07:20 PM

It turns out that the gasket is in place so that's not the issue. but i can confirm that there is about 3/4" of movement possible on the far corner from where the hinge is located when the fan is completely closed tight. This is what is able to vibrate with the wind and traveling at highway speeds.

I'm really surprised to hear that no one else has this issue.

I'm not sure there is any room to add the additional cover as suggested since there are solar panels on either side of the fan mounting. Unless the the cover fits, right on top of the white plastic fan mount area.

GallenH · 03-04-2022, 11:57 PM

Can you use some type of selfadhesive pad (furniture pad, door bumper button) on the inside of the cover to prevent movement? Perhaps on the base instead.
Something like

https://www.amazon.com/Dampone-Adhes...s%2C172&sr=8-5

eric1514 · 03-05-2022, 12:36 AM

Have you been able to get on top to inspect the lid? Perhaps it's cracked or broken, maybe near the hinge, and the closing mechanism can't draw it down tight.

jls · 03-07-2022, 08:12 PM

Yes i have inspected it. The plastic lid is just pretty flimsy (but no cracks) so there is enough cross-play from the corner where the hinge is to the other far corner where it can bounce up and down on the gasket. Surprisingly annoying sound!

GallenH · 03-07-2022, 09:52 PM

Out of curiosity:

If you detach the raise/lower arm from the top so the top is completely free, is there any play at the hinge at all?

Is there any play in the raise/lower arm with it in the open position? How about in the closed position (which might indicate some sort of problem with the closing mechanism)?

Is there any indication that the top has been previously replaced, perhaps with a cheap brand? I had to replace mine once. The replacement was like the original: plastic was very stiff, unbendable.

avanti · 03-07-2022, 10:23 PM

This is a tough one.

I just went out and looked at my fan. As best I can tell from the inside, when it is closed it is closed.

Do you get the same problem when you crank it down using the knob, rather than the motor? Wondering if it could be something in the motor's gear train.

jls · 03-08-2022, 09:34 PM

When i crank it down by hand full tight it is the same as when the motor closes it. Maybe just a tiny bit tighter but hardly a noticeable difference in flappiness.

I will give Fantastic Fans a jingle and see what they have to say...

Rusczyk56 · 03-10-2022, 06:07 PM

Word is warning... Shimming or other additions may make for water entry. The lid must fully rest all four side flush on the rim of the roof mounted flange. If not, water will find it's way in either from wind or driving in rain.. Fact is the design is cheap and not long lived.

jls · 03-10-2022, 06:49 PM

Yes, that's a good reminder. thanks!

I did speak with Domestic about the issue and they suggested to replace with their dome-top cover (vs. the flat top one i have now). Alternately they said there could be an installation issue. I'm kinda doubting that since i've found other reviews from people with the same issue i'm having.

Beckerdvm · 03-13-2022, 03:11 PM

Yes, my Fantastic Fan in our 2017 Agile rattled at speed above 65mph. I called Dometic several years ago and they also told me to replace the flat cover with a dome one. It helped but did not completely stop the rattle. It is evidently caused by the solar panel in front of it causing air flow turbulence. From the outside, I added a small piece of self adhesive foam insulation to the flange under the corner that rattled and that completely solved the problem. It has been quite for several years.

jls · 03-13-2022, 07:27 PM

That's exactly the kind of solution i was looking to find. I just want to understand your solution as best i can so i can try to replicate it.

The "flange" is the plastic lip of the fan housing that sticks up vertically from the roof, right?

How thick of a piece of foam insulation did you use - does it fill the whole gap between the flange and lid? does it touch or apply pressure to the lid?

How long of a piece of foam insulation? it's sound like a pretty small piece worked if it's "just under the corner that rattled"

thank you!

Beckerdvm · 03-13-2022, 10:40 PM

Good questions, sorry that I was not more specific...
The "flange" is the plastic lip of the fan housing that sticks up vertically from the roof, right? Yes, the cover has a vertical edge that comes down on the outside of the flange.

How thick of a piece of foam insulation did you use ...I used 1/2 inch wide and 1/2 inch thick soft black foam insulation with white paper on the back that is removed to expose a sticky surface. I first cleaned the flat surface with denatured alcohol - does it fill the whole gap between the flange and lid?... At first I applied it to the flat surface outside the roof flange all the way around the opening. It worked great but the fan motor had difficulty opening the fully closed lid. It was binding between the foam and the vertical edge of the lid. I then removed all but a 1 1/2" strip on the side that was rattling by the back corner. does it touch or apply pressure to the lid? ...yes, the lid rests on it when fully closed. That pressure is what prevents the rattle. I rested a ladder on a blanket on the awning cover and it was easy to reach all but the far side. You can experiment with different thickness and length of foam to see what works best for your cover.

How long of a piece of foam insulation? it's sound like a pretty small piece worked if it's "just under the corner that rattled" 1 1/2 long (see above)

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