General Roof Vent Question

[Zupfront]

I have been thinking about van dwelling for years and recently bit the bullet on a 2011 Chevy Express. I have finished up most of the work one must do when buying a used vehicle so now I am moving on to my conversion. I am definitely leaning toward the necessity of a roof vent after reading much here. I have slept a few nights in the van and these are my thoughts so far.

Heat is not a big issue for me as I already don't use AC and it is often 90+ degrees when I go to sleep. It was actually cooler in the van than in my bedroom. However I did have one night where I ended up quite cold. All I had for clothing was my underwear and just a few cheap polyester blankets to sleep on and cover up with. I spent the whole night awake and shivering so I am sure insulation will be necessary for the cold. When I add the insulation it is going to take much longer for the van to reach the outside temperature. This will be good when it is cold but bad when it is warm, so a roof vent will be necessary to help regulate temperature.

I often see the Fan-tastic vent recommended here. I don't have any plans to add any solar power so the fan will not be seeing much use. There is a dome light I plan on disconnecting that I assume I can hook the fan into, but since I will be running off the van's battery it will only see use when it is running. My questions are as follows:

Is a roof vent as necessary as I am reading it to be?
Is it a large help in moisture control?
How much more noticeable will the heat be after I insulate if I don't add a roof vent? I was planning on doing something like 1-1.5" Polyiso on the walls and roof and a lesser amount on the floor. I know that is a hard question to answer.
Does the fantastic vent allow much air flow when the fan is not running?
Would it make more sense to simply buy a vent with no fan in it? 
I didn't have any plans for it but would getting a house battery be worth it?
Is it much trouble to connect it to the alternator to charge it? I have no electric experience.



I have read a lot of threads but it is still hard to judge so I would really appreciate any help with those questions or general feedback.

 

[29chico]

I am going to refer you to the below link.  It is the thread that brought me to this forum in the first place.  Load of good info there.  Most of it is from SternWake out resident electrical, battery and ventilation guru.

Link;

https://vanlivingforum.com/Thread-Vent-Fan-on-Roof-or-No-vent-Fan-Solutions?page=2

 

[Zupfront]

I am going to refer you to the below link.  It is the thread that brought me to this forum in the first place.  Load of good info there.  Most of it is from SternWake out resident electrical, battery and ventilation guru.

Link;

https://vanlivingforum.com/Thread-Vent-Fan-on-Roof-or-No-vent-Fan-Solutions?page=2

Thanks, it's an interesting read. Most seem to agree ventinaltion is necessary. Hopefully those with experience can chime in on my questions.

 

[Almost There]

I would only add these two suggestions to anything else you're going to read:

1. Place your roof vent somewhere where it is NOT over your bed. OR

2. Make darn sure that when you put in the roof vent you also put a MaxAir/Camco cover over it.

Yes, there are vents available with rain sensors - guess what, they take rain falling already to sense that there's rain there...IMO another marketing guru who didn't think things all the way through.

Failure to do either or both of the above will have you sleeping on a wet bed sooner or later... :dodgy:

I can sit in my van in 90F weather with a portable table fan going and the roof vent open (I seldom use the fan in the vent) and be reasonably comfortable in the heaviest of downpours. Between the roof vent, the fan aimed at me and the rain guards on the two front windows, I'm good!!

 

[Zupfront]

2. Make darn sure that when you put in the roof vent you also put a MaxAir/Camco cover over it.

I was trying to maintain somewhat of a stealth factor so I do not think that will be an option for me. Why do you think it is necessary for a properly installed vent to have one?

 

[Almost There]

I was trying to maintain somewhat of a stealth factor so I do not think that will be an option for me. Why do you think it is necessary for a properly installed vent to have one?

Simply because you'll want to leave it open when you leave the van and it's Mother Natures'  guarantee that sooner or later it will start to pour rain on your vehicle while you're away from it. Either that or you'll park is somewhere on a hot sunny day and the sprinkler system will come on next to it..

And Mother Nature always wins!!

The other thing is, I can run down the highway with the vent open without it making all kinds of fluttering noises. The manual crank on the roof vents hasn't been significantly redesigned since I first started using them back in the 70s. They flap in the breeze. When there's a vent cover on it, nada!!

Stealth is IMO, hugely overrated and not often successfully done. People worry about it way too much!!

I've seen roof vents and covers on everything from cargo trailers to police vans. They only signify that someone for some reason wanted hot air to escape.

 

[Zupfront]

Stealth is IMO, hugely overrated and not often successfully done. People worry about it way too much!!

I've seen roof vents and covers on everything from cargo trailers to police vans. They only signify that someone for some reason wanted hot air to escape.

I've not looked into them but I assume they are easily mountable afterwards. So if I do put a roof vent in and later decide I want a cover I could add it I suppose.

 

[Almost There]

I've not looked into them but I assume they are easily mountable afterwards. So if I do put a roof vent in and later decide I want a cover I could add it I suppose.

Ha, you're one of the ones' that will wait until you've had a rain episode.....

And yes, there's 4 brackets that go under the corner mounting screws on the roof vent. Subsequent installation just means backing out 4 screws, reinserting them with the bracket in place and attaching the cover.

After checking out the MaxAir and the Camco covers last winter in Quartziite, I asked the guy at the supplier what the difference was except for the $10.00 price difference. He said MaxAir had the name (more expensive) but in his opinion the Camco was a superior design. The vent on the Max Air is not screened and cannot be separately removed for cleaning the vent cover and the top of the vent screen. The Camco is itself screened and has 4 screws holding the rear grid panel in place so it can be removed for access.

I haven't gotten up on the roof to remove and clean the screen yet but sitting here looking at, it should go on my housekeeping list - which means I may get to it next winter....

 

[rvpopeye]

A Fantastic on low will draw about the same power as the old incandescent bulb did. Replace the bulb with an led and use both !
What AT said about a vent cover x2. Just get one you won't regret it.
(Make sure it's a high volume one so it doesn't restrict airflow on high setting)
It is also VERY quiet on low so not really noticeable from the ground.

And yes they can be added at any time , actually bolt to the bottom frame on the sides.

 

[highdesertranger]

I vote a roof vent is mandatory. with the optional cover you can keep it open in the rain. very important. imho. highdesertranger

 

[Zupfront]

A Fantastic on low will draw about the same power as the old incandescent bulb did. Replace the bulb with an led and use both !
What AT said about a vent cover x2. Just get one you won't regret it.
(Make sure it's a high volume one so it doesn't restrict airflow on high setting)
It is also VERY quiet on low so not really noticeable from the ground.

And yes they can be added at any time , actually bolt to the bottom frame on the sides.

I still imagine it draining the battery far too fast to use if the engine isn't running.

Do you guys find that yours allows for much air flow without the fan on?

 

[highdesertranger]

even without the fan running they make a big difference. gives that hot air that sits up high somewhere to go, out. highdesertranger

 

[rvpopeye]

How long do you expect a dome light to go without draining the batt too much , same with a Fantastic.about 1.5 amps....
BUT on high ,,,900 cubic feet per minute ! and STILL only the same as 2 incandescent lights . 3.5 amps
(unless they have changed a lot since I bought mine in '05.)

(We're not raving about them cuz we get paid , but because we have experienced how they work ! and the factory support was super too.....)

 

[Spaceman Spiff]

The MaxxFan Deluxe has a built in rain guard.  Doesn't stick up as far as the add-on guards.  I've had mine in some heavy driving rains with no water infiltration ('cept for the time I had it sucking the air in while raining hard :blush: ).  Sticks up about 2" higher than a standard roof vent when closed.  And I do drive with it open at times.

FWIW, if you are running your engine every day and your starter battery is in good shape, I don't think running a ceiling fan is going to wear your battery down.

 -- Spiff

 

[Zupfront]

Thanks for the feedback guys.