RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×


Reply
 
Thread Tools Display Modes
 
Old 05-29-2016, 08:18 PM   #1
Mini-Skoolie
 
Join Date: May 2016
Posts: 13
New and have an a/c question

I have a 1992 International 3800 with a Carpenter Bus Body that is converted. It currently has a portable a\c that doesn't work very well. I want to go with a roof top unit. It is a full size bus with the last 8 or so feet walled off for use as storage (not cooled). Will one 15k btu roof top u it work to cool the bus? I'm in Texas and I like it to be very cool! Thanks in advance
Jhughes08 is offline   Reply With Quote
Old 05-29-2016, 09:18 PM   #2
Skoolie
 
Join Date: Mar 2016
Location: chicago, il
Posts: 220
Year: 2003
Chassis: IC CE
Engine: T444
Quote:
Originally Posted by Jhughes08 View Post
I have a 1992 International 3800 with a Carpenter Bus Body that is converted. It currently has a portable a\c that doesn't work very well. I want to go with a roof top unit. It is a full size bus with the last 8 or so feet walled off for use as storage (not cooled). Will one 15k btu roof top u it work to cool the bus? I'm in Texas and I like it to be very cool! Thanks in advance
That entirely depends on your buses dimensions. However, if you have what i am assuming is 30 feet of livable space. No, you will need more cooling my skoolie of 21.5 ft by 7.5 ft wide by 6.2ft tall would use 15k btus to maintain cooling. Also as it is Texas you will probably need even more than normally recommended as the heat is at a higher temperture more consistently. Google btu to cool a space, you should see a few sites that have instant calculators. This will give you a rather accurate number on required btu's.
Azuleslight is offline   Reply With Quote
Old 05-29-2016, 10:50 PM   #3
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,128
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
depending on how many rows you have you will want 2.. and im assuming this is just for when you are parked.. if you want rooftop units to cool you while driving good luck... lots of engine and road heat is introduced into the bus when moving down the freeway at 65...

it also depends on how well your conversion was done when it comes to insulation.. and how quickly you want to cool it.. if you want to leave your bus shut-down all day (generator off).and cool it down quickly when you come home to it.. that also affects how much cooling you need..

if you are looking to cool it while driving you may need a unit that blows into the driver compartment.. maybe you keep that portable for that? or install Dash-air...

-Christopher
cadillackid is offline   Reply With Quote
Old 05-30-2016, 09:55 AM   #4
Mini-Skoolie
 
Join Date: May 2016
Posts: 13


I'll measure and take a few more pictures today. If I went with one unit I was going to put it in the front and **** the door to the back while driving. I think I'll do one now and then add the second later due to cost. I appreciate the responses, I'm very excited to have this resource.




***fixed picture link too many[/url] [/img] in it, Bansil
Jhughes08 is offline   Reply With Quote
Old 05-30-2016, 10:50 AM   #5
Bus Crazy
 
Scooternj's Avatar
 
Join Date: Apr 2014
Location: EHT New Jersey
Posts: 1,134
Year: 2003
Coachwork: AmTran
Chassis: International 3000RE
Engine: T444E/AT545
Rated Cap: 75
Quote:
Originally Posted by cadillackid View Post
it also depends on how well your conversion was done when it comes to insulation.. and how quickly you want to cool it.. if you want to leave your bus shut-down all day (generator off).and cool it down quickly when you come home to it.. that also affects how much cooling you need..
Insulation is a huge key. Some converters don't pull any of the panels and leave the old insulation in place. Not only is the old fiberglass inefficient, but leaving the steel panels in place creates a huge thermal bridge that allows all your cold back out into the rest of the world, forcing the AC to work even harder. And if the wall between the living and storage space isn't insulated either, you have the same problem- a huge thermal bridge, forcing your 15k btu AC to work harder to cool the space in the bus.

A second key thing to remember is the roof. Is it white/reflective color or does it have a deck on top? Because if the answer is "No" to either, and you've left your bus out in the Texas sun all day, you're also forcing your AC to work harder to cool off that space.
__________________
Hey! That's not an RV, that's a school bus.
Well thank you for noticing, Captain Obvious

Captain Obvious on deviantArt
Scooternj is offline   Reply With Quote
Old 05-30-2016, 11:25 AM   #6
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,128
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
initial core cool down is the toughest thing your A/C will endure... you can drop the air temperature a few degrees fairly quickly.. and with Dash / road air you have the advantage you are blowing cold air on your body so you feel cool..

once the air begins to cool a few degrees.. then that air begins to take in the heat of the surrounding items on the bus... the reverse of radiant heating... your air now becomes the heat exchanger medium .. those core parts hold a lot of heat... metals.. woods, plastics, etc.. as azules mentioned, once you start cooling those parts down is where insulation and sun-shield becomes key..

unlike dash air, when you are parked, you are living in your bus more like a home and therefore want the core cool, not just the air.. thus when you sit in a chair, lean against a wall.. are away from the air unit itself you want to be cool.. (or warm in winter)..

in a home some of this is overcome because your A/C is often just turned on all the time so the core temp stays cool and the A/C has a fighting chance during the heat of the day by using the cool core to its advantage..

thus why I ask how you are planning to use the bus? if you plan on running the air even when you are away from it (but going to return later in the day).. or do you shut it off? if you are planning to run on the road alot, then you have engine heast to overcome.. and will likely want either a dash air.. or that portable up front to keep the driver cool.. those big windshields and engine bring in a lot of heat...

you will also want to seal up air leaks from your engine compartment.. dynamat the floors and firewall inside.. insulate and seal the dog-house, close your heater valves under the hood.. (or install electrically operated ones).. and Close the outside air intake for the defrosters.. (normally a lever on the driver console... oftentimes frozen open, so you will need to disassemble the heater box around the driver (good idea anyway).. and repair that air flap door...

-Christopher
cadillackid is offline   Reply With Quote
Old 05-30-2016, 08:25 PM   #7
Mini-Skoolie
 
Join Date: May 2016
Posts: 13
I'm going to use it as a camper only. So when I am using it the ac will stay on. I'd like to shut off the front and use one unit while driving. Me and my grandfather did this bus about 10-15 years ago. We used foam board in the walls and in the back wall then spray foamed the edges. Then ceiling insulation was not changed out so its the fiber glass. I'm am about to put a white thermal rubber type sealant on the roof that is supposed to seal and block some heat. I am going to also paint the firewall with it to help with engine heat. No windows were removed so I know that's a lot of heat transfer.

<iframe width="480" height="360" src="http://s1079.photobucket.com/user/jhughes08/embed/Mobile%20Uploads/story"></iframe>
Jhughes08 is offline   Reply With Quote
Old 05-31-2016, 04:34 PM   #8
Bus Geek
 
bansil's Avatar
 
Join Date: Nov 2011
Location: MNT CITY TN
Posts: 5,158
here you go

http://www.skoolie.net/forums/f10/ho...-op-11846.html


I did a step by step for photobucket
__________________
Our build La Tortuga
Accept the challenges so that you can feel the exhilaration of victory.
George S. Patton
bansil is offline   Reply With Quote
Old 05-31-2016, 07:45 PM   #9
Mini-Skoolie
 
Join Date: May 2016
Posts: 13
Mobile Uploads Slideshow by jhughes08 | Photobucket
Jhughes08 is offline   Reply With Quote
Old 06-01-2016, 03:07 AM   #10
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 2,131
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
That appears to be a Mitchell, IN built Carpenter bus. I have one as well (older model). These buses had some issues with faulty welds where the roof bows meet the tops of the windows, unfortunately since Carpenter is no longer in business and the problem was not discovered until after the fact, there's no real way to force a recall. Not all had this issue, I suppose it depends on who was doing the welding that day it was built. It probably won't pose any issue as long as it isn't involved in a rollover (which was how the problem was discovered in the first place).
Brad_SwiftFur is offline   Reply With Quote
Old 06-01-2016, 07:25 AM   #11
Bus Geek
 
bansil's Avatar
 
Join Date: Nov 2011
Location: MNT CITY TN
Posts: 5,158
Quote:
Originally Posted by Brad_SwiftFur View Post
That appears to be a Mitchell, IN built Carpenter bus. I have one as well (older model). These buses had some issues with faulty welds where the roof bows meet the tops of the windows, unfortunately since Carpenter is no longer in business and the problem was not discovered until after the fact, there's no real way to force a recall. Not all had this issue, I suppose it depends on who was doing the welding that day it was built. It probably won't pose any issue as long as it isn't involved in a rollover (which was how the problem was discovered in the first place).
Good eye!!

Here is some info for inspection
Carpenter School Bus Advisory

__________________
Our build La Tortuga
Accept the challenges so that you can feel the exhilaration of victory.
George S. Patton
bansil is offline   Reply With Quote
Old 06-01-2016, 07:50 AM   #12
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,128
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
I have a mitchell carpenter as well and mine was updated / repaired... I thought the problem was discovered before they were defunct and many of the busses were repaired...

I know one thing, carpenter made a Solid bus but they did cut some corners on some things however others they were excellent.. (like open your electrical box and Note EVERY SWITCH is on a 20 amp circuit breaker.. And there are plenty of spare breakers.. Plus most of the carpenters have a 200 amp capable solenoid that controls the main switch panel.. it makes wiring things up VERY easy!


if you have an 86 or newer.. Now lets talk CRAPPY HEATER DESIGN! in the driver console are 3 heater motors.. one for the Left defrost, a driver foot warmer.. and a heater that blows directly out the back of the console onto the feet of the person in the first row seat.. there is a SINGLE heater core core mounted HORIZONTAL! oh and the air is sucked in the top and over the coil then blows out.. so this coil easily gets clogged with dirt. and you have to disassemble the heater unit to clean it.. (half of the coil is visible, half is covered by the outside air intake..)..

Next remove the vertical panel that goes top to bottom just to the left of the steering wheel.. its easy.. and Note the CARDBOARD duct that channels the defrost air from the Bottom of the heater box up to the windshield...

its not all carpenter's fault I guess because they did sub the heaters out to bergstrom.. and the defrosters in the 86+ are much better than previous..but still going to require some upgrading to get them right...

my next project is to rebuild both of my 2 front heater boxes and perform upgrades to the blowers and motors where i can...
-Christopher
cadillackid is offline   Reply With Quote
Old 06-01-2016, 02:48 PM   #13
Mini-Skoolie
 
Join Date: May 2016
Posts: 13
I have heard about the roof bow problem before and mine is a Richmond model, will this affect the roofs ability to hold a 90 lb ac unit in the front and one in the back? I can walk on the roof and it doesn't have any movement at all (I weight about twice what the ac would)
Jhughes08 is offline   Reply With Quote
Old 06-01-2016, 02:59 PM   #14
Bus Geek
 
EastCoastCB's Avatar
 
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 22,558
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
Crapenters, Waynes, Wards... I like the "crappier", older, lesser known buses. IDK why but I really do.
Every school bus I've ever messed with (like maybe 5 total) were various brands and they were all build pretty well and pretty much the same.

I've seen at least a couple LATE Carpenters that were really nice. I wanna say they were like 1994's?
__________________
.
Roll Your Own Build Thread
EastCoastCB is offline   Reply With Quote
Old 06-01-2016, 03:07 PM   #15
Mini-Skoolie
 
Join Date: May 2016
Posts: 13
This one is a 1992, its in decent shape. Someday I'd like to get a Bluebird pusher and do it.
Jhughes08 is offline   Reply With Quote
Old 06-01-2016, 03:49 PM   #16
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,128
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
mine is a 1991 carpenter and in good shape.. the Only advantage I see to the bluebirds, thomas's, IC is that parts are still available for the bus part..

my carpenter I cant find a driver window anywhere... mine is a mess.. sre the glass I can have re-made but not the missing weather seal that doesnt seem to exist anywhere.... my old bluebird was an 86 and had a hacked driver window when I got it.. I just ordered a whole new one from bluebird... for a bus that was 23 years old...

if you have an IC from say 2001 up thats still the same IC they make nowadays.. you can find anything for them.

granted I like the feel, look, and cool-factor of old busses. superior was my favorite.. carpenter second.. but it is hard to find body parts..
-Christopher
cadillackid is offline   Reply With Quote
Old 06-01-2016, 04:08 PM   #17
Bus Geek
 
bansil's Avatar
 
Join Date: Nov 2011
Location: MNT CITY TN
Posts: 5,158
Quote:
Originally Posted by Jhughes08 View Post
I have heard about the roof bow problem before and mine is a Richmond model, will this affect the roofs ability to hold a 90 lb ac unit in the front and one in the back? I can walk on the roof and it doesn't have any movement at all (I weight about twice what the ac would)
is the picture on page 1 your bus?

It doesnt look like one?


yours page 1
__________________
Our build La Tortuga
Accept the challenges so that you can feel the exhilaration of victory.
George S. Patton
bansil is offline   Reply With Quote
Old 06-01-2016, 06:16 PM   #18
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 14,128
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
the second pic is a crown low top.. I thought they built low and high top carpenters in mitchell and low and high top crowns in richmond...

I know my carpenter says mitchell on its indoor tag above the driver seat.... it could be that at some point they were making transitions when it became crown by carpenter?

-Christopher
cadillackid is offline   Reply With Quote
Old 06-01-2016, 10:40 PM   #19
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 2,131
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
The Mitchell IN buses were the ones said to have the roof bow issue. The Richmond models are not. Either one should have no problem with a roof mounted AC unit. The problem is where the bows were welded above the windows, and 99% of the time it's not a problem. The defect was only discovered after a rollover in (Florida, I think it was) where the roof collapsed down to the seats and an investigation was done. As long as you keep your bus upright, it should be alright. Not all Mitchell buses had this problem, many were inspected, some were OK, some had a few bad welds, some had many (or all) bad welds. But there's no way to know without removing the inside panels to check. Since many of us do this anyway, it's good to know so you can check. Re-welding should restore the structural integrity to what the factory designed.
Brad_SwiftFur is offline   Reply With Quote
Old 06-01-2016, 10:42 PM   #20
Bus Crazy
 
Join Date: May 2016
Location: Georgia
Posts: 2,131
Year: 2001
Coachwork: Blue Bird
Chassis: IH
Engine: T444E
Rated Cap: 14
Quote:
Originally Posted by cadillackid View Post
my carpenter I cant find a driver window anywhere... mine is a mess.. sre the glass I can have re-made but not the missing weather seal that doesnt seem to exist anywhere.... my old bluebird was an 86 and had a hacked driver window when I got it.. I just ordered a whole new one from bluebird... for a bus that was 23 years old...
You want me to see if there's one where I got my bus? There were 2-3 buses, not sure if all were Carpenter bodies or not....
Brad_SwiftFur is offline   Reply With Quote
Reply

Tags
a/c, btu, roof top

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


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 06:41 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
×