air ram for camper back

Submitted: Tuesday, Jul 28, 2009 at 18:12

ThreadID: 71043 Views:3146 Replies:5 FollowUps:2

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Russell & Mary

Question time.. I'm building a sheet metal box type canopy for the back of a mates ute. I want to build into it a ram air scoop on the side near the front to pressurise and help keep dust out. He says the intake should face toward the back to keep out rain and bugs, but I say it won't act as a scoop, only a venturi and will suck air out. What do you think? Rus

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Reply By: Member - Allan B (QLD) - Tuesday, Jul 28, 2009 at 19:08

Tuesday, Jul 28, 2009 at 19:08

Hi Rus,

Certainly a rear-facing scoop will lower the pressure in the canopy whilst a forward-facing scoop will raise the air pressure and hopefully prevent the ingress of dust.

Rain? Well if the canopy is not vented elsewhere then the pressure buildup will reduce the airflow into the scoop and minimise the intake of rain. But you may get some.

Bugs? Same for bugs but an insect screen should solve that anyway.

There was a thread on this a few days ago. Go look.

Cheers
Allan

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AnswerID: 376590

Reply By: Member - Scooby (WA) - Tuesday, Jul 28, 2009 at 19:35

Tuesday, Jul 28, 2009 at 19:35

Hi Rus,
I have two forward facing scuppers ( I think that is the correct term) mounted on the front vertical face of the canopy,. They are used on boats and available from places like Whitworths Marine and flip up open and snap closed with a spring. Helps stop dust ingress, cools down the canopy inside where the fridge is and can be shut if it rains. Works for me.
Regards
Scooby

AnswerID: 376593

Reply By: Member - Leigh (Vic) - Wednesday, Jul 29, 2009 at 13:15

Wednesday, Jul 29, 2009 at 13:15

If you face them backards I suspect you will create a vaccum and draw dust in from vulnerable areas. Face it forward and if concerned stick an air filter on the inside of the canopy to stop dust from passing vehicles. Cheers

AnswerID: 376658

Reply By: Russell & Mary - Wednesday, Jul 29, 2009 at 16:08

Wednesday, Jul 29, 2009 at 16:08

Thanks for the replies guys. My mate is still adamant that an aero friend of his said they should face backwards. I've tried searching the net under topics like "ram air", "air scoops", etc but can't find anywhere to corroborate his line on this one. I might make it reversible, then he can try it either way. Thanks, Rus.

AnswerID: 376682

Reply By: Member - Roachie (SA) - Wednesday, Jul 29, 2009 at 17:09

Wednesday, Jul 29, 2009 at 17:09

I have a couple of purpose-made air vents designed for the exact purpose you describe. They were on the top of my dual cab's canopy when I bought it because the original owner used to cart 2 large dogs around in it and needed the air flow in. He also had a solar-powered extraction fan, but I've already sold that.

The 2 air vents are here at my place and you can have them for the price of the postage if you like.

I've just mucked around on the net trying to find ones the same, but can't locate a photo. They require a hole about 3" diameter plus 4 mounting holes. They are sort of tear-drop shaped, have an opening at the front, but wont allow water in if it rains etc.

Let me know..... I've been going to chuck 'em out, but haven't been able to bring myself to do so (I'm a real hoarder!!!! hahahaha).

Roachie

AnswerID: 376688