Wind speed on roof of trailer?

W

wopachop

Well-known member
Joined
May 5, 2021
Messages
906
Reaction score
374
How much wind do you think happens between the roof and about 6 inches high? For example the roof vent. Has anyone been inside an RV or class C and looked at the standard roof vent while driving down the road? Does it see much turbulence? 

Asking because i have a MaxxAir roof vent. I want to mount it sideways on the trailer. I wrote MaxxAir customer service. Took 2 weeks for a reply and it had spelling errors. They said it has to be mounted normal or it will be damaged while driving. Im not so sure that is correct. Most of the wind speed might happen more like 1 foot above the trailer....maybe? The roof vent itself is designed to handle sideway blowing wind while parked. Doing 60mph down the road might only give the roof vent something like 20mph of wind speed blasting around it. 

One added benefit is the AC unit is literally 2 inches away from the roof vent. So it has an additional wind block. In a way i wonder if the roof vent will actually see backwards airflow from the eddie formed by the AC unit. Or the wind will miss the vent completely. 

 
I should be more clear its the MaxxAir deluxe that has the fan and build in motor that raises the vent to open it while running. Then it folds down while driving. 

 
I got the old school vents & close them every time I drive.  even when Im parked in Glamis I can hear them blowing all over the place.  especially the forward one that is not in the plastic shield.  (dont ask me why they put the shield on one & not the other, but its been this way since day 1.  If I were to do it again, I would put the shield on both of them.). 

My point is I would be super concerned about it being sideways going down the highway.  they are only plastic.  to be fair......... I have not looked really hard @ the new ones your talking about. 

Roof 1, 1Mar21.jpg

 
Last edited by a moderator:
The new vent is much stronger than the standard vent. 

As it sits now the vent will get 20-30mph winds blowing at the back. 

Years ago one broke and blew off. Trailer is a 2013. Got lucky it didnt rain super hard before i found it missing.

 
Problem is how the trailer gets parked. The wind blows pretty darn strong right at the back of the trailer. My bathroom has that standard fan like most trailers. If i open that vent and turn the fan on the wind will still come blowing into the trailer. Over powers the fan. I usually crack the vent about 1 inch open and then turn the fan on. Allow for the air to exit the trailer. Its not very efficient as the fan is trying to blow against incoming wind. 

Cant leave the vents open because every time somebody drives down the road a huge cloud of dust hits the trailer. 

I have 2 options. 

Mount the new fan sideways. 

Build a little wind deflector behind the new fan. 

 
I feel like mounting sideways wont be an issue because of all the times ive forgotten things on the roof of my truck. Or my bumper. Ive been truly amazed how the items dont blow off at freeway speeds. I had a folded stepladder on my roof that just stayed there planted. I remembered as i was doing 65 on the freeway. Scary because i could have caused a major accident over a bonehead maneuver. Been shell shocked on doing that mistake again ever since. Couldnt believe it was still on the roof once i pulled over. 

 
FWIW, this thing on the rear one on my trailer makes big difference.  the rear one does not flop around nearly as much as the one on the front that does not have it....

71DNgTDHcML._AC_SL1500_.jpg


 
Got it temporary mounted without sealant. Decent little unit i guess. Its pretty quiet on high. Pulls 2.2amps. Its got a thermostat feature that looks promising. Strangely even when i set to 34F the fan only pulls 1.7amps. No biggie just means it doesnt go to high. If i remember correctly 90% was around 1.5amps. Thought it was funny the 10 settings of 0% to 100% couldn't recreate the 1.7amps that auto mode did. Auto mode lives its own life man!!! To me thats a design flaw though. Its saying room temp 94F and thermostat set to 34F. It really should pull the max 2.2a. 

20220816_174832.jpg

 
This thing is torquey. The sideways mount is working decent enough. I should take a video real quick. You can hear the outside wind effecting the fan. If it was mounted normal i think it would be way worse. 

 
Got a leaf blower? Test it out with tufts of yarn taped to it.

 
Last edited by a moderator:
Yes recently used a leaf blower on the outside of my trailer. Darn mice try to build nests in my genny. I have sticky traps in there. I think there is a scent trail right to it. Rodents cant control their pee it just leaks out on the common paths they take. Have used an air compressor forever to blow out the genny. The leaf blower worked much better!! Did the water heater and also my wheels under the covers. Looked like a few black widow webs on them. 

Heres a boring vid. Was trying to catch the sound of wind as it hits the fan that is mounted sideways. Might build some wind baffles for the fan down the road. I expected the sideways mount to work a little better. Yesterday wasnt all that windy. 



 
I put 2 of those units on my moho, not sideways and w/o the thermostat. They are nice. Fans are quiet. Push and pulls air depending on what you want. I usually keep both on low while plugged in camping. 

As far as them being sideways, the 'lids' are very different from the standard lid on a regular vent cover and may not be effected as much.

 
On super low speed do your fans make a click sound Matt? 

Im experimenting with an idea today. Very curious how hot my trailer will be when i get back later. Its usually over 100F. Walk inside and instant sweat. 

 
Can anyone guess the experiment? I blocked the vent with cardboard. The plastic is just so i can see up there. Make sure the fan opened. The plastic and cardboard are sealed tight. 

Hint: The toyhauler has 2 other vent openings. 

20220817_101226.jpg

 
DAMN they are proud of those............ 

 
You must log in or register to reply here.
Back
Top