Fantastic Wind Noise

[jlarry214]

Okay, I'm new to the forum and was reading some old posts. I found one on the above subject but it must have had a different subject line. My question is, can you use the whole cover that the person installed instead of cutting it down as shown in the photo.

Thanks,
Larry
1999 Concourse

[Blue~Go]

I just noticed this post, and that no-one ever replied. Not sure if you are still wondering (or reading!), but sure, you can use the whole cover. They are meant for the purpose. I'm sure it would eliminate any noise as well or better than just the partial cover. I'm guessing the Chinooker who cut down the vent cover had one of the below reasons.

Reasons I can think of for not using the whole cover:

1) You like the sky view out the vent.
2) You want maximum airflow (even without using fan).
3) You want the vent lid to open 100% of the way.
4) You don't want the look or the potential solar panel shading of the whole cover.

Reason for using a (whole) vent cover (the main one anyway):

1) You can leave vent open in the rain.

[caconcourse]

I just noticed this post, and that no-one ever replied. Not sure if you are still wondering (or reading!), but sure, you can use the whole cover. They are meant for the purpose. I'm sure it would eliminate any noise as well or better than just the partial cover. I'm guessing the Chinooker who cut down the vent cover had one of the below reasons.

Reasons I can think of for not using the whole cover:

1) You like the sky view out the vent.
2) You want maximum airflow (even without using fan).
3) You want the vent lid to open 100% of the way.
4) You don't want the look or the potential solar panel shading of the whole cover.

Reason for using a (whole) vent cover (the main one anyway):

1) You can leave vent open in the rain.

Hi,
Guess I missed the original question also. I can confirm my reasons for cutting down the cover were 1-3 above. Number 4 is a good reason also, but I hadn't thought about it. The MaxxAir cover reduces the air flow of the Fantastic Fan a lot. There is a special cover from the Fantastic Fan people that works better but it costs more. I think they have a you-tube video on their website demonstrating the difference. I have a new smoke-colored fan lid that lets in more light (it's similar to a tinted windshield) than my original cover that had yellowed to the point it was nearly opaque.

I considered using one of the MaxxAir covers on my bathroom fan (I found them in a dumpster), but I realized that if rain comes in that opening, I don't care. It's a shower stall after all.

A lot of people use the MaxxAir covers, including Chinookers.

Clay

[Blue~Go]

Hi Clay,

I know, how did we all miss this, right?

I've been meaning to tell you that I obtained one of those exact same covers (a friend removed it and was going to toss it), cut it down, and tried it. I cut it on the same line as you. Well, it maybe reduced my wind noise 30%. Hmmph. I want it GONE. The only difference I can think of is that I set it down on the roof and not on the vent frame. So it was a bit further forward than yours (which also meant the vent lid didn't hit it). And as a result of that, I cut the back out entirely (but the adhesive I used kept what was left, "square"). So maybe just the slightly different positioning made the difference (?).

I then bought a whole one and put that on temporarily. That did help. But I hated it up there. Blocked all the air (so I HAD to use the fan if I wanted any air), blocked the view, vent wouldn't open all the way, etc.

I saw that special Fantastic cover and considered it. Slightly bugged me that I guess from reading the vent lid still doesn't open all the way, and I still don't want that big lump there at all. Like you, if I were going to leave a vent open in the rain it would be the bathroom one.

So I'm going to try a couple of other things. Now I took a couple of pieces of "half round" I had lying around and stuck them to the front/vertical flange. Haven't driven yet to try that. I also have that whole cover I bought that I may try to cut down slightly less and mount further aft. I haven't given up yet! Ultimately if nothing works I'll put something else besides a "sticky uppy" roof vent in the hole (but I think I can get something to work).

[jlarry214]

Thanks for the comments and info. This will give me plenty to think on. The wind noise really bothers me. I didn't have this much noise when I was using a pickup and overhead camper.

Thanks again,
Larry

[Blue~Go]

Thanks for the comments and info. This will give me plenty to think on. The wind noise really bothers me. I didn't have this much noise when I was using a pickup and overhead camper.

Thanks again,
Larry

Hi Larry,

Glad you were still around to see this! I agree about the wind noise. It's ridiculous! I, too, had a pickup and a topper/camper back in the day (no overcab) and it wasn't noisy at all. I also had a camper van with a pop top; not this noisy!

When I spoke with Jerry at Fantastic Vent (he has run an RV service department), he said they have this trouble a lot with RV's that have the vent very close to the front of the roof (as ours is, just aft of the "upswoop"). They made dams, and did various other things.

I'm NOT going to continue with the noise. Ugh! Right now I'm trying two pieces of half round on the upright flange (in case it's the wind hitting that that does it). Next I will make a small fiberglass dam. Next (if there has to be a next) I'll take the bloody vent out and relocate it and just have a flat skylight there!

Reason I think it might be wind hitting the upright flange is that I have already gone to a "double" (insulated) dome. You would think that if it was wind hitting the dome that the double dome would at least have changed the noise (it didn't). I also taped the whole entire lid to the flange just in case it was air noise (it wasn't; no change). I also taped foam insulation over the vent hole on the inside to make sure it WAS the vent doing it (that lessened the noise, so it is the vent).

The only thing I can think of that is left is that upright flange (Jerry agreed). Given that Clay took care of the noise by essentially blocking that off, is another clue.

I'll certainly report back if anything works.

BG

[kdarling]

Weird. I don't think I hear this noise. I have an aerodynamic cover on the front vent:

http://www.amazon.com/Camco-40421-Aero- ... vent+cover

OTOH, if I open up the big passenger side slide window, it's noisy as heck while driving. I'm tempted to put air dams in front of the window to see if I can prevent it.

Kev

[Blue~Go]

I think the difference is the cover. When I put the full cover on mine to experiment, the noise was probably 80% gone, and if I had not "known it was there," that remaining 20% level might never have caught my attention. I just don't particularly want a hood there. But without the hood (and without any wind leakage whatsoever) it's just LIKE having a window open.... only it isn't open

I will solve it one way or another - I'm determined. Winter just isn't a "fast" time to solve it as I don't tend to drive that much -- so there is a lag time between experiments.

[caconcourse]

Hi Clay,

I know, how did we all miss this, right?

I've been meaning to tell you that I obtained one of those exact same covers (a friend removed it and was going to toss it), cut it down, and tried it. I cut it on the same line as you. Well, it maybe reduced my wind noise 30%. Hmmph. I want it GONE. The only difference I can think of is that I set it down on the roof and not on the vent frame. So it was a bit further forward than yours (which also meant the vent lid didn't hit it). And as a result of that, I cut the back out entirely (but the adhesive I used kept what was left, "square"). So maybe just the slightly different positioning made the difference (?).

I then bought a whole one and put that on temporarily. That did help. But I hated it up there. Blocked all the air (so I HAD to use the fan if I wanted any air), blocked the view, vent wouldn't open all the way, etc.

I saw that special Fantastic cover and considered it. Slightly bugged me that I guess from reading the vent lid still doesn't open all the way, and I still don't want that big lump there at all. Like you, if I were going to leave a vent open in the rain it would be the bathroom one.

So I'm going to try a couple of other things. Now I took a couple of pieces of "half round" I had lying around and stuck them to the front/vertical flange. Haven't driven yet to try that. I also have that whole cover I bought that I may try to cut down slightly less and mount further aft. I haven't given up yet! Ultimately if nothing works I'll put something else besides a "sticky uppy" roof vent in the hole (but I think I can get something to work).

Hi,
Sorry the cutoff vent cover did not eliminate your noise. My fairing is also on the roof around the flange, not on it, so the fan cover doesn't touch it when open. I think you were on the right track, I would try leaving more of the MaxxAir front in place (leave two tiers instead of just one) to make sure the airflow is completely over the fan lid. I was going to try some noise reduction shape (like sharks teeth) if I still had the problem. See pictures of the 787 Dreamliner engine fairings, to see how Boeing muffles their engine noise. It is all about the flow. I am guessing like you that the source of the noise is the wind hitting the vertical front of the fan cover head on, creating a lot of turbulence. So the fairing needs to continue the flow from the over-cab slanted front up and all the way over the fan. It's possible the air conditioner might even help, because its fairing encourages the air to go higher after the fan.

Even if you left the front two tiers of the MaxxAir cover in place, it probably wouldn't interfere with the vertical view or keep the cover from opening all the way. You could even cut the second tier front like a flap, so it can bend backward in the wind and bend forward when the fan lid is all the way open (if there happens to be any interference). Since the whole cover worked, I would start cutting layers from the top and test it until it stopped working or stopped being obnoxious.

Here is a new picture of my Chinook from the front showing my new paint job of the trim over the cab, along with the fairing and open fan. (The paint is darker than the original silver because the paint company messed up, but they gave me my money back, and it still looks way better than the old peeling clear coat.)

Clay

[Blue~Go]

Clay,

Thanks for the tips. I do have the one intact cover to still play with (and was thinking like you said, just cut it down less). Shark teeth might be cool And/or I have some sheet fiberglass I could fab up into a fairing shape.

Just curious though: I thought you left the full perimeter of the cut down cover, and if so, didn't the rear flange land awkwardly?

I don't mind blocking the "view" from in front of the Fantastic Vent, as long as I can open it all the way. OTOH, with the full cover in place, it wrecked the view from my "skylight" where the Air-con used to be. Can't have that!

BTW, the wind noise was just as bed before I removed the Air-con. I drove around 6,000 miles with it that way.

I'm very interested to try a quick drive with just the two strips of (wooden) half round stuck to the upright flange. Would be kind of sweet if that fixed it. Talk about easy and unobtrusive.