Reply
 
Thread Tools Display Modes
 
Old 07-24-2016, 08:13 AM   #1
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 7,183
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
roof hatch without passive vent??

does one exist? my roof hatch is definitely SHOT on my bus... not only was it the type you could pop for vent it also has a passive always-open vent which on paper sounds nice.. but causes negative pressure on the bus.. sucking in more air from outside sources when driving... ie engine compartment heat that I have yet to seal..

I cant seem to find any non-vented roof hatches.. I dont mind the fact that they can be opened.. but ai dont want that possive vent.. I dont need to worry about humidity in the bus, I have Air-conditioning and can even pre-refrigerate the defrost if I need to for humidity control..

my current one is a Transpec so thats the ones ive been looking at since it would be an easy drop in replacement....

-Christopher
cadillackid is offline   Reply With Quote
Old 07-24-2016, 08:26 AM   #2
Skoolie
 
RHOMBUS's Avatar
 
Join Date: Feb 2015
Location: South Dakota
Posts: 196
Year: 2002
Coachwork: Thomas
Chassis: Freightliner HDX
Engine: CAT 3126B250
Rated Cap: 84
I thought they only vented if you popped up one side, allowing them to say "vented roof hatch." Mine are the normal ones too and I don't think they have an open air channel unless I pop one side up.

I was looking into getting one with an integrated fan, but that's a little pricey for my taste and I never thought about it sucking in air instead of exhausting it. Hmmm.
__________________
My project: The Cruel Bus
RHOMBUS is offline   Reply With Quote
Old 07-24-2016, 08:34 AM   #3
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 7,183
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
when I had mine apart iot mentions passive venting and theres a channel from inside the bus up to the top and I notice the ones I find online have vent-holes..

the hatch itself doesnt suck air in.. it creates a negative pressure on the bus at road speed which will tend to suck air in from other sources...

negative pressure is also created by your mirrors.. thus why when you open your driver window you may actually be Hotter in your bus as it is creating more negaitive pressure which will exploit any holes in the firewall and other places in the bus... the passenger windows starting a row or two back are out of the mirror draft and will usually bring in air when opened..

wind deflectors on car windows work on the same principle to create negative pressure so you can have your window down but not get wind in your face...

in my case I dont want negative pressure on the bus as im running windows closed with the A/C on when its hot like now.. or if I want my driver window open I want the mirror pressure relieved so I can have air blowing on me (I love a nice sultry evening drive windows open and AC blasting...).. so I made a temporary reverse deflector i can place on the driver window when I open it to snag some outside air..

-Christopher
cadillackid is offline   Reply With Quote
Old 07-24-2016, 08:58 AM   #4
Bus Nut
 
Join Date: Dec 2015
Location: pa
Posts: 470
Year: 1998
Coachwork: corbeil
Chassis: ford e350
Engine: 7.3 powerstroke
Not sure if large bus escape hatches are different from small buses,... e350 corbeil...but mine that I am working on , see thread can be fully closed.

With the four spring loaded arms you can set it up the way you want. You can lift it up a s scoop, positive pressure so air will be blown in or as a negative pressure as your is.

The piece i cut out to make a skylight out had another vent in that also could be set up as positive or negative pressure. That was a steel add on.

What do you mean with a channel inside the bus? Is it hooked up to some duct work in the ceiling?

Later J
joeblack5 is offline   Reply With Quote
Old 07-24-2016, 10:17 AM   #5
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 7,183
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
my hatch has a permanent channel open from outside to inside.. it appears baffled.. but I havent ripped it apart till I get a new hatch.. the transpec hatches ive been seeing all have that "vent" hole in the hatch itself.. this vents even when the hatch iod l;atched and closed.. not when its in a vent position..

my guess is that they are ,made this way because when carrying a bus load of people in col or damp weather you have a high amount of humidity..
-Christopher
cadillackid is offline   Reply With Quote
Old 07-24-2016, 11:56 AM   #6
Bus Nut
 
Join Date: Jun 2016
Location: Garden State (rural NJ)
Posts: 383
Christopher, can you simply block/plug the channel with a bit of butyl or silicone caulking?
BusFiend is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Virginia Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 11:26 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.