Reply
 
Thread Tools Display Modes
 
Old 06-19-2017, 12:31 PM   #1
Bus Crazy
 
Stu & Filo. T's Avatar
 
Join Date: Sep 2013
Location: Vacaville, Ca
Posts: 1,624
Year: 1988
Coachwork: Crown / Pusher
Engine: 8.3 Cummins
Roof Top AC Units

Getting to the point in my conversion where I'm going to be piecing the interior together, One of my plans is to have 50amp service with 3 DUCTED low profile roof mounted Ac Units, My neighbor thinks thats overkill & that 2 will be more than sufficient, I've got 2in of insulation on the floor with 1 & 1/8" T&G subfloor & will have 2 & 7/8" of spray foam on the walls & ceiling. All windows have been removed & skinned over & I'm installing tinted RV Windows where needed.

Whats been the outcome of other members? 2 units wish you had gone with 3, 3 would have been happy with 2,Wish you'd never started in the first place?? what are your thoughts.
Stu & Filo. T is offline   Reply With Quote
Old 06-19-2017, 12:48 PM   #2
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,212
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
I would put in 3 and here's why... unlike an oversized house system, with multiple units you can turn on as few or as many as you need for a particular situation...

you may find that at night once the bus is cooled down that 1 can maintain it.. but if you were out all day and had shut off the genny or were parked without shore-power.. then kick all 3 on and cool it down nice N quick...

you can still maintain humidity by turning off one or 2 if you are over- capacity..

those phoenix 120 degree days in summer if you happened to travel that way are gonna require more than you think to keep cool..
-Christopher
cadillackid is offline   Reply With Quote
Old 06-19-2017, 08:44 PM   #3
Bus Crazy
 
Njsurf73's Avatar
 
Join Date: Jan 2017
Location: Massachusetts
Posts: 1,497
Year: 2002
Coachwork: Bluebird
Chassis: Bluebird
Engine: 5.9 Cummins 24v
Rated Cap: 72 pax
I wonder. If you can afford 3, you may find that 2 does the trick most/all of the time... But having a third for backup or the couple of times a year that extreme temps show up (unless you have extremes all the time).

Sent from my XT1254 using Tapatalk
Njsurf73 is offline   Reply With Quote
Old 06-19-2017, 09:02 PM   #4
Bus Crazy
 
Stu & Filo. T's Avatar
 
Join Date: Sep 2013
Location: Vacaville, Ca
Posts: 1,624
Year: 1988
Coachwork: Crown / Pusher
Engine: 8.3 Cummins
Quote:
Originally Posted by Njsurf73 View Post
I wonder. If you can afford 3, you may find that 2 does the trick most/all of the time... But having a third for backup or the couple of times a year that extreme temps show up (unless you have extremes all the time).

Sent from my XT1254 using Tapatalk
I've seen higher priced S&S's running 5 Units, there will be times when we'll be in extreme areas plus humidity, As long as I'm able to take the edge off during the day I can cope but I need to be comfortable when I sleep. Since I'm going to be ducting I want to do it right the first time.
Stu & Filo. T is offline   Reply With Quote
Old 06-19-2017, 09:40 PM   #5
Bus Nut
 
Join Date: Aug 2010
Posts: 346
Year: 1995
Coachwork: Thomas
Chassis: International
Engine: 466DT
Rated Cap: 65
I started out with one 15,00btu roof top AC. 1 inch styrofoam in the flor walls and 1/2" with the factory fiberglass in the ceiling. Parked and not driving one did pretty good in 90+ high humidity. Black bus, 4 rv windows. Eventually the 1/2 on the ceiling let loose from the wrong glue so I took it down. Ever since then it struggles with 1 AC in 90+ temps. I did add a second 13,500 rooftop and can run both off my old onan genny, while runnning down the road. Makes it pretty comfortable. Only running the one down the road at those temps gets pretty warm. I made the mistake of only doing a 30 amp shore power service and should have done 50 amp.. That will change soon in the next couple years. Long story short, go 3 and you won't regret it. It's easier to plan for 3 now, then to try and add another later.
Hvbuzz is offline   Reply With Quote
Old 06-20-2017, 01:46 PM   #6
Bus Crazy
 
Stu & Filo. T's Avatar
 
Join Date: Sep 2013
Location: Vacaville, Ca
Posts: 1,624
Year: 1988
Coachwork: Crown / Pusher
Engine: 8.3 Cummins
I sent a text to an old Air Force buddy who has a 40ft Class A with 2 AC units & he tells me he's happy with the two, spends most his time between Texas & Florida plus the bus is going to be far more insulated than his RV.
Stu & Filo. T is offline   Reply With Quote
Old 06-20-2017, 06:43 PM   #7
Site Team
 
JDOnTheGo's Avatar
 
Join Date: Feb 2017
Location: The West
Posts: 1,004
Year: 1998
Coachwork: MCI
Chassis: 102 EL3
Engine: DD 60
I had two 13.5 BTU AC's in my 40' Newmar Dutch Star and always found them sufficient. I did avoid terribly high temperatures though. I'm planning two 15K units in my bus. If you plan to be 'in the heat' planning for three AC units seems like a wise choice.
__________________
JD - Full timer out west
Missy - 1998 MCI 102-EL3 - 1.7kW Solar - 10kWh Lithium
My Adventures & Build
JDOnTheGo is offline   Reply With Quote
Old 06-20-2017, 06:48 PM   #8
Bus Crazy
 
Njsurf73's Avatar
 
Join Date: Jan 2017
Location: Massachusetts
Posts: 1,497
Year: 2002
Coachwork: Bluebird
Chassis: Bluebird
Engine: 5.9 Cummins 24v
Rated Cap: 72 pax
Quote:
Originally Posted by Stu & Filo. T View Post
I sent a text to an old Air Force buddy who has a 40ft Class A with 2 AC units & he tells me he's happy with the two, spends most his time between Texas & Florida plus the bus is going to be far more insulated than his RV.
Where are you sourcing them from?

Sent from my XT1254 using Tapatalk
Njsurf73 is offline   Reply With Quote
Old 06-20-2017, 07:40 PM   #9
Bus Crazy
 
Stu & Filo. T's Avatar
 
Join Date: Sep 2013
Location: Vacaville, Ca
Posts: 1,624
Year: 1988
Coachwork: Crown / Pusher
Engine: 8.3 Cummins
Quote:
Originally Posted by Njsurf73 View Post
Where are you sourcing them from?

Sent from my XT1254 using Tapatalk
Shopping eBay & Amazon
Stu & Filo. T is offline   Reply With Quote
Old 06-20-2017, 07:43 PM   #10
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,212
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
camping world up here just had a big sale on A/C units.. im sure the sales are regional, but seems they advertise every few weeks in summer for having A/C units for sale.. maybe their prices are too high? their biggest gimmick now is the "get a brand new motorhome for $499 a month out the door 0 down..
-Christopher
cadillackid is offline   Reply With Quote
Old 06-20-2017, 08:47 PM   #11
Bus Crazy
 
Join Date: Jun 2013
Location: Picton,Ont, Can.
Posts: 1,784
Year: 1997
Coachwork: Bluebird
Chassis: GMC
Engine: Cat 3116
Rated Cap: 72
I'd go three and place them strategically throughout the bus depending on your floor plan.
Besides you have backup if any should fail at some point. Get the hard work done by installing all three at once and have no regrets.

John
__________________
Question everything!
BlackJohn is offline   Reply With Quote
Old 06-20-2017, 08:48 PM   #12
Traveling
 
Join Date: Nov 2015
Location: Midwest
Posts: 2,573
Year: 2003
Coachwork: BlueBird
Chassis: TC2000
Engine: 5.9L Cummins
Rated Cap: '00
Mike has pair of 15k units in a 40' sprayfoam, no windows bookmobile. Works good enough for me.

When calculating loads for AC , consider windows (size, panes & direction facing), insulation and people.

Single dude in a RV puts off a lot less heat than family of 6. Engine running will add to thermal load. Vehicle color will have impact.

That being said, I'm probably going to add even more insulation as it is cheapest long-term solution to thermal migration.
Rusty is offline   Reply With Quote
Old 06-20-2017, 09:47 PM   #13
Bus Geek
 
Robin97396's Avatar
 
Join Date: Feb 2016
Location: Willamina, Oregon
Posts: 6,409
Coachwork: 97 Bluebird TC1000 5.9
Amen to that. In this one winter I recaptured about 65% of the cost of insulation with reduced heating bills. That sounds good for normal circumstances, but this was an unusually severe winter in this area.
__________________
Robin
Nobody's Business
Robin97396 is offline   Reply With Quote
Old 06-21-2017, 12:14 PM   #14
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 5,737
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
On my last bus we insulated with 1.5" of spray foam in the walls & ceiling. We installed two roof airs (12.5k) and they kept us cool until outside temps passed 110F.

We spent plenty of time in the Mohave Desert in August and saw temps run in the mid to upper 120's for weeks at a time. I would have killed for a third AC at that time.

On my next bus I am going to install similar AC capacity. I will NOT be visiting AZ in August though......

Equip for the climate you will be spending time in. If you see yourself traveling in extreme climates be prepared. If, like me, you will be in the North during the Summer and South in the Winter then 3 AC's would not be needed.
PNW_Steve is offline   Reply With Quote
Old 06-21-2017, 01:48 PM   #15
Bus Crazy
 
Stu & Filo. T's Avatar
 
Join Date: Sep 2013
Location: Vacaville, Ca
Posts: 1,624
Year: 1988
Coachwork: Crown / Pusher
Engine: 8.3 Cummins
Quote:
Originally Posted by BlackJohn View Post
I'd go three and place them strategically throughout the bus depending on your floor plan.
Besides you have backup if any should fail at some point. Get the hard work done by installing all three at once and have no regrets.

John
Yea I've always been the type where I rather have it & not need it than need it & not have it, But it is another $1000.00
Stu & Filo. T is offline   Reply With Quote
Old 06-21-2017, 04:33 PM   #16
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 12,212
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
Quote:
Originally Posted by Stu & Filo. T View Post
Yea I've always been the type where I rather have it & not need it than need it & not have it, But it is another $1000.00
then run the wires for it and leave the roof space for it... if you cant swing the $1000 now but find you need the A/C later then its just a matter of cutting a hole and dropping a unit in.
-Christopher
cadillackid is offline   Reply With Quote
Old 06-21-2017, 05:58 PM   #17
Bus Crazy
 
Join Date: Mar 2011
Location: Oregon/Philippines
Posts: 1,660
I have two 13.5 on roof.... and in the wall small window unit above the head of my bed in the back of the bus, which vents out in the small room for the washer n storage above the engine compartment... Nothing like cool air while one snoozes. Wish I had done this trick on the other 4 busses i converted over the last 30 yrs..
__________________
Jesus Christ... Conversion in progress.
chev49 is offline   Reply With Quote
Old 06-21-2017, 08:58 PM   #18
Bus Nut
 
Dog Rescuer's Avatar
 
Join Date: Mar 2017
Location: On the Road
Posts: 577
Year: 2000
Coachwork: BlueBird
Chassis: International 3800
Engine: 7.3L 210HP Turbo Diesel T444E
Rated Cap: 28 + 3 wheel chairs.
How challenging (for the sheet metal challenged) would it be to cut 14" x 14" hole in the roof for a roof vent? I didn't want to cover the emergency hatches just yet...
I need a roof vent in the hotest of ways!




Quote:
Originally Posted by cadillackid View Post
then run the wires for it and leave the roof space for it... if you cant swing the $1000 now but find you need the A/C later then its just a matter of cutting a hole and dropping a unit in.
-Christopher
__________________
- Roger (Dog.Rescuer)
Dog Rescuer is offline   Reply With Quote
Old 06-22-2017, 05:20 AM   #19
Bus Crazy
 
Join Date: Mar 2011
Location: Oregon/Philippines
Posts: 1,660
v ery easy to cut a hole in the roof... however i make one side next to a roof rib for support. Also quite easy to cut the side of the bus out and install a rv door with its frame. In the case of a bus with lower compartments, the compartment floor is the first step for the stairs, and the floor has to be cut out as well. If i do another bus, i will do with the roof as i have seen one bus. Cut it off same as for raising, save it for a run to the crusher, and use new tubing and steel sheeting to make flat roof. Then inside is nice and square like a house ceiling. Is an extra 1k or so for steel, but so much easier to work with instead of the rounded ceiling, the escape hatches, speaker holes and so forth.
__________________
Jesus Christ... Conversion in progress.
chev49 is offline   Reply With Quote
Old 06-22-2017, 09:48 AM   #20
Bus Crazy
 
Join Date: May 2014
Location: West Ohio
Posts: 1,274
Year: 1984
Coachwork: Bluebird
Chassis: International 1753
Engine: 6.9 International
Rated Cap: 65
Quote:
Originally Posted by Dog Rescuer View Post
How challenging (for the sheet metal challenged) would it be to cut 14" x 14" hole in the roof for a roof vent? I didn't want to cover the emergency hatches just yet...
I need a roof vent in the hotest of ways!

It's really simple. I used a hole saw in a drill and a set of good tin snips to cut the hole(both left and right cut snips are a must). I put mine in the middle of the roof ribs and then went overboard and welded a 3/16 inch thick square plate for the gasket to sit on(I wanted it to be as flat and sturdy as possible). I also inserted 2x2 wood in between the inner and outer skins and ran 2" screws from both top and bottom to hold it all together. Mine has 0 movement, and also 0 leaks
Booyah45828 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


» Featured Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 08:44 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×