Creating vent opening in panel

[Jeremy]

I need to create ventilation openings in the skin of my bus in two places - a large one where the generator is mounted, and a smaller one for the compartment housing the inverter. Both will have substantial fans mounted behind the opening sucking air in from outside. The panels where the vents are to be added are the aluminium skin of the bus - in one case a fixed panel, and in the other a bay door.

I can think of various ways of doing it, from the basic (cutting a big hole and attaching a mesh grille) to the more sophisticated (eg somehow punching louvers in the panel). All my ideas have a flaw somewhere though, so I'd be interested in hearing anyone else's suggestions. What I really want to achieve is an OEM-type look, preferably with something that sits flush with the panel, and definitely without any ugly rivet-heads showing on the outside if at all possible.

There are a couple of smallish vents in the body already which use a neat black plastic injection-moulded type grille opening attached to the panel. Something like that but much bigger would be ideal, but I've never come across a supplier for such things other than small ones sold by DIY stores for houses

Any recommendations?

Jeremy

[Chopper Scott]

I used some stainless steel mesh panels that actually are intended to be donut racks!!  I got them off of Ebay. Here's a link to a screen he has listed. It is a 23 x 23 but I got a 19 x 19 from him. Later

http://cgi.ebay.com/Stainless-Steel-Donut-Frying-Screen-23-x23-DN-FS23_W0QQitemZ220375859746QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item334f6cc222&_trksid=p3911.c0.m14&_trkparms=65%3A12%7C66%3A2%7C39%3A1%7C72%3A1205%7C293%3A2%7C294%3A50

[Kwajdiver]

Try this, works for me, plenty of air flow to the genset.

Bill

[Kwajdiver]

Or this,,,,,

[Kwajdiver]

Meant to post this photo...

[Jeremy]

Thanks Kwajdiver - can you remember where you bought those?


Jeremy

[jackhartjr]

Jeremy, you said you are sucking air in, I assume this is to help in the cooling of the units...are you also making vents or a way for the warmed air to vent outside?
Thanks
Jack

[Jeremy]

That's a fair question, and the answer is that the back of the inverter compartment will vent into the space behind the compartment, and the bottom of the generator space is planned to be open to the ground. This latter aspect is something I'm not sure about though, regarding sound insulation - I'm intending to heavily insulate above the generator (ie. under the floor of the bus), and also have as much insulation around the sides of the generator as I reasonably can - but is all this pointless if the sound can exit the bottom and bounce back up from the ground? I'm not so worried about sound coming out sideways from the ventilation grille as that sound will be traveling away from the occupants.

The generator is a 3.5kw enclosed petrol unit with a smart throttle and the correct anti-vibration mounts, so I'm not overly worried about noise - just trying to avoid any obvious mistakes!

Jeremy

[BG6]

ChopperScott:

How heavy duty are these?  Well made?  Are they tough enough that someone couldn't just yank them apart?

[Kwajdiver]

You can buy all the vents I used at most marine supply stores, ie, US Boat.   

No, one is going to just yank them off.  They are stainless steel.

My genset, has a hole in the floor for air flow and changing the oil.  When sitting, the fan on the gen sucks in lots of air.  One may have been enough. 

Bill

[Chopper Scott]

BG6..... They are pretty well made. After all they have to hold up several dozen bear claws and long johns every day with big paws dragging them out!!  Beings they are stainless steel they are pretty strong anyways. I got the 19 x 19 ones and cut  openings into the rear side doors smaller. Then I used 10/32 stainless bolts and nuts and drilled out some stainless flat steel to make washers and mounted the panels on the inside with only the heads showing on the outside. The little flat stainless washers I made cover the outside rod that is the framework of the screen. My door sides are flat aluminum sheets. In my application they work fine as there is really no pressure against them other than an air relief. Hope that helps. I need to take some pics. Later

[NewbeeMC9]

Won't nock these off with a bush

http://www.racerpartswholesale.com/product/2141/Naca_Ducts2

[alltech]

I was looking a Northwest RV Supply in Eugene Oregan and they seemed to have a good selection of the Injection molded vents for just that purpose. He gets most of his surplus straight from the coach manufactures

Regards,

Ross

[Jeremy]

Ross:

That sounds like just what I want - does the company you mention have a website by any chance? Sacreligious as it may sound, I would prefer plastic rather than metal for this application, although I have since thought of a chandlers I know that is likely to stock the sort of grille that Kwajdiver used. The ducts that the race car site describe as 'NACA ducts' (most of them aren't) wouldn't do as they are intended to be connected to a hose.

I'm a bit worried about how much rigidity will be lost from the panel by cutting a large opening into it. I'd like to be able to fold the edge of the opening into a lip of some sort to add some stiffness, but I'm not sure how best to go about this without running the risk of distorting the panel.

Jeremy

[alltech]

Jeremy

Here is the site, I looked at them online last night but there site is down for maintenance today!

http://www.nwrvsupply.com/

Rergard,

Ross