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Why do we install a roof vent?

PostPosted: Mon Oct 03, 2005 6:35 pm
by Mightydog
When you search this topic, over 1,000 responses show up--none of them seemed to address this question so I'll give it a shot:

Why do we put big roof vents in teardrops?

This weekend found me shoping for a roof vent as it's something you should probably have in-hand before you work the spars on the top too much. You want to rough-in the framing to support the vent. If it has a fan, you want to run wire to it. It struck me that I didn't know why we install such huge vents in our teardrops.

There is a roof vent in the Camping World catalog that goes into a 6-1/2 inch diameter hole. It moves 100 cfm of air. By my rough math, our 5-wide by 8-long by 4-high teardrop, minus the galley and considering the curve, might be between 75 and 100 cubic feet. That means we can clean out the air in it in about a minute.

If you put a 14- by 14-inch roof vent, the effect is greater. I found one fan that, on the low setting, it could move 685 cfm. It could move all of the air out of our tear in about 10-seconds! High setting would be about half that.

Sure, we all want to keep carbon monoxide poisioning from happening. We're planning to put windows in each door--it would seem reasonable to think that we could get a cross-draft working to keep oxygen in our brains.

In looking at the piece on RV Crazy, only about half the tears had roof vents in them.

Is the vent there as a skylight? Is it there for fresh air? Is it there as yet another way to admit moisture? Am I pondering this too much?

What say you members of the Teardrop Braintrust?

PostPosted: Mon Oct 03, 2005 6:40 pm
by toypusher
Mine is in place of the Air Conditioner. I was camping back in August when the overnight temp was around 85 and the humidity was out of site. Sure glad I had that Fantastic vent fan. Reversible is really nice too. You can get air in the windows or have it blow straight down on you.

Just my opinion!

PostPosted: Mon Oct 03, 2005 6:43 pm
by Arne
i think a vent is not entirely necessary, but it goes provide natural ventilation with a window or two open. I leave mine open during the day, only about an inche or two, with the awning windows open to get rid of that 'slept in' aroma..... just like i throw the bed covers back during the day.

it also lets in a lot of natural light during the day.... sometimes too much in the summer, when the sun rises about 5.30 around here.

PostPosted: Mon Oct 03, 2005 7:30 pm
by GeorgeTelford
Hi

I have bought a few computer fans, a single 80mm can easily shift 28 cfm, the power usage is minimal.

for cooling down in hot weather even a light breeze over your body allows you natural heat dissapation to make you feel comfortable.

PostPosted: Mon Oct 03, 2005 7:54 pm
by emiller
8) Heat rises so it's nice to have a vent.

PostPosted: Mon Oct 03, 2005 8:08 pm
by stjohn
come on guys you missed the obvious , you had chili dogs for lunch pinto
beans and rice for supper confined space need I say more :lol: :lol: :lol
have a nice evening

Mike

PostPosted: Mon Oct 03, 2005 8:23 pm
by asianflava
Why use a 6in fan that moves 100cfm at high speed (louder) when you can get a larger fan that will move 100cfm at low speed (quieter). Since you will be less than 4ft from the fan, noise will be a factor.

Maybe because "Standard" roof vents are 14X14. There are so many made that it probably the most economical. I'm not saying cheapest, I'm saying economical best performance vs. price.

PostPosted: Mon Oct 03, 2005 9:26 pm
by emiller
:drofl: Good one stjohn

PostPosted: Mon Oct 03, 2005 10:37 pm
by Chris C
That's exactly why I want a roof vent, St. John. My girlfriend and I are both "gas powered" models. :rofl2: :lol: 8)

PostPosted: Mon Oct 03, 2005 10:48 pm
by mikeschn
Mightydog,

Definitely use a roof vent to keep cool, especially when you don't have an air conditioner in there.

A fantastic fan or Northern Breeze moves the most amount of air very quietly. Definitely a consideration being so close to the roof vent.

Mike...

PostPosted: Mon Oct 03, 2005 11:23 pm
by Ma3tt
I don't know, I've been in 102 degree heat and no vent just my EZup shade thing and wife and I were very comfy. But it is a dry heat!

PostPosted: Tue Oct 04, 2005 1:52 am
by madjack
Ma3tt wrote:I don't know, I've been in 102 degree heat and no vent just my EZup shade thing and wife and I were very comfy. But it is a dry heat!


...yeah, right :lol: ....oh by the way, I have some lovely farm land in south Louisiana I would like to sell ya :D ;)
madjack 8)

p.s. I have an option on a bridge in Brooklyn also...if your interested

PostPosted: Tue Oct 04, 2005 9:42 am
by Rob
Mightydog--
We sleep with two adults and a dog in the trailer. We frequently have to open the doors at night to cool the place down. A roof fan is one thing that I wish we had. I have been contemplating cutting a hole in the roof to install one, but just haven't got the guts to do that yet. We have some small fans in the door windows that help, but a quiet roof fan sure would be nice.

Rob

PostPosted: Tue Oct 04, 2005 11:00 am
by toypusher
In a single word - GAS! :oops::? :? :lol:

PostPosted: Tue Oct 04, 2005 12:56 pm
by Mightydog
I love this group: you get all of the reasons you want a roof vent!

BTW: Stop by my tear sometime for chili dogs
Image
with plenty of onions!!

We're going to be needing that 1,275 cfm fan for sure!