Installing an "escape hatch" vs Vent..or both?

[JJPDX]

One of the first conversion videos I watched featured a van with an "escape hatch," which the owner loved.  I'm imagining a very tall van, with tilting Solar etc.  Thinking, with the right set-up, an escape hatch would make roof access much easier. Also in bed sky watching/ telescope viewing comes to mind.  Sure there will be space/location consideration; water sealing; bug screen etc.  And I'd still want a vent with fan.  Can I have it all!!??  anyone have both? Combine a vent and fan into an escape hatch?  Thoughts?  Products?  I've searched the forums with several key words but not a lot comes up. 

I know, I'm such a Newbie I don't even know what box I'm thinking out of...

Much thanks, jj

 

[TMG51]

I considered one. I also decided that with roof space at a premium, rather than have separate roof vent and hatch, the two should be combined with the vent installed on a larger hinged platform. There would have to be some kind of a lip on the van roof, and the hatch would rest over that, so that water doesn't get in. I decided against doing this in my van since it's a factory class b with layers of fiberglass, wiring, plywood, etc in the roof, but I think it's doable from scratch.

 

[johnny b]

This place has hatches/vents....no combo with fan though:

http://www.rvandvansurplus.com/ventselector.asp

 

[DannyB1954]

My 1974 Kings Highway has an escape hatch with small fan in it. The problem that I see with it is it does not appear to be very strong. If a body can get out of it, a body can get in as well. like I said not very strong plastic cover.
A marine supply may be your best bet. look for hatch cover, and then add a fan to it.
Here is one on ebay that looks like a good deal. http://www.ebay.com/itm/Goiot-23-x18-Boat-Hatch-Cast-Aluminum-Frame-Acrylic-Window-/272247320524

 

[SternWake]

A fan works much better when it is shrouded in the opening so that the air moved does not make a U turn and get recycled through the impeller.


I am a great fan of fan speed control, not only for airflow, but noise, and amp draw considerations.

I use computer fans, 120 and 180MM for air exchange.  Some of these have built in speed control, but one can speed or slow a DC fan with a PWM motor speed controller or LED dimmer.

One could do the radiator fan in the larger hatch for some really crazy air movement, and Dial it down with a PWM speed controller, but it might not be very efficient at slow speeds.

[/img]https://images-na.ssl-images-amazon.com/images/I/71txeh51aOL._SL1024_.jpg[/img]

https://www.amazon.com/LongBang-Mot...7&sr=1-13&keywords=pwm+motor+speed+controller

With computer fans, the larger sizes can move a lot more air for a lot less noise and amp draw.

Computer fans vary greatly in air movement, from slow and whisper quiet with barely  a breeze...... to screaming banshee chop off a fingertip type of power, and send a dense column of air clean across the Van.

 I installed this in a stick and brick bathroom as an exhaust fan in a window. I used an acrylic shroud to let in as much light as possible and exhaust as much air as possible with some velcro to hold shroud to window.

http://www.frozencpu.com/products/1...Black_BFF-SPRO-23030KK-RP.html?tl=g36c15s1393.

If i had a large hatch in my roof I'd probably fill it with 2 or 4 of these fans, or similar, in an acrylic shroud on a hinge and have a remote speed control reachable from the bed.


In case the screaming banshee  fingertip chopping computer fan doubters exist, it resides here:

https://www.amazon.com/Delta-TFC121...=1464853528&sr=8-1&keywords=delta+252+cfm+fan


I could not get the one I ordered to slow to a reasonable enough speed before it would shut down Still draws 2.3 amps at minimum speed and still moves huge volumes of air.  It is too loud for use in the van.

The silverstone fm121 has become my computer 120Mm fan of choice.

Keep in mind these fans will build up considerable amount of dust on the blades and screens and need to be cleaned every so often to remain efficient, and cleaning fan blades is time consuming.

 

[wagoneer]

cabover truck campers typically have an escape hatch above the bed area without a fan and a 14 x 14 vent above the galley at least mine does. installing a fan for the 17 x 24 opening would be counter productive.

 

[wagoneer]

cabover truck campers typically have an escape hatch above the bed area without a fan and a 14 x 14 vent above the galley at least mine does. installing a fan for the 17 x 24 opening would be counter productive.

using my 12 volt larger fan on the bed would move air

 

[Wanderer]

Can't see the need for such....Vent "Might" be a bigger size, but trade off is also that (As one said) "They can enter it as well as exit" but it does take some doing.

 

[TooManyDogs]

The high top van I'm buying has a Transpec escape hatch. I researched it and some models come equipped with passive pop-up vents and with fans. Google "Transpec escape hatch" for sources.