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05-07-2022, 02:52 PM
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#1
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Mini-Skoolie
Join Date: Mar 2022
Location: Western NY
Posts: 24
Year: 2006
Chassis: International RE300
Engine: DT466E, Allison 5 speed
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Auxiliary Yanmar
Hello all.
New here seeking advice.
Bus has an auxiliary Yanmar midship underbelly for the factory a/c.
Looking for pros and cons of this setup.
Our plan is to have an off grid solar setup and we’re looking for reasons to keep the Yanmar or dump it for additional storage.
I get keeping factory a/c has benefits but what other benefits (if any) would there be to keeping the Yanmar instead of freeing up the real estate?
Kindly,
Daniel
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05-07-2022, 03:51 PM
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#2
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Bus Geek
Join Date: Sep 2017
Location: Swansboro,NC
Posts: 3,124
Year: 86
Coachwork: Thomas
Chassis: Ford B700
Engine: 8.2
Rated Cap: 60 bodies
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you dont want it?
pull it out and i will pay shipping.
it probably powers more than A/C but we dont know because you have not filled out your profile.
not trying to be rude we just dont know what platform you have.
if you have a handicap bus then it could keep the a/c running and power the handi lift when the bus engine is dead and on the side of the road.
hard to tell until you tell us what you have?
but if you dont want the generator then let us know.
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05-07-2022, 04:08 PM
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#3
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Mini-Skoolie
Join Date: Mar 2022
Location: Western NY
Posts: 24
Year: 2006
Chassis: International RE300
Engine: DT466E, Allison 5 speed
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Sorry,
We don’t own the bus yet.
Have a line on a 2004 IC300 RE.
Planning ahead.
Kindly,
Daniel
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05-07-2022, 08:23 PM
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#4
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,845
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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thst was a common thing on many older busses, to have a separate engine to run just the Air Conditioner
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05-08-2022, 08:35 AM
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#5
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Mini-Skoolie
Join Date: Mar 2022
Location: Western NY
Posts: 24
Year: 2006
Chassis: International RE300
Engine: DT466E, Allison 5 speed
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Cadillac,
What would you use it for?
Can you make an argument to keep it onboard?
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05-08-2022, 08:36 AM
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#6
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Mini-Skoolie
Join Date: Mar 2022
Location: Western NY
Posts: 24
Year: 2006
Chassis: International RE300
Engine: DT466E, Allison 5 speed
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Roger,
Can you make a case to keep it?
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05-08-2022, 08:54 AM
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#7
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,845
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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Quote:
Originally Posted by BuffaloBink
Cadillac,
What would you use it for?
Can you make an argument to keep it onboard?
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Grr!! the forum once again killed my post!!
anyway the system is most designed to be road A/C, however you can operate it when the bus is parked without the main engine running.. they also usually have a pretty biug alternator so they can generate electricity along with run A/C for charging batteries (and jump starting the bus if you kill the bus batteries)...
often Gasoline engine bussesd came with these aux systems because gas engines got hot idling or didnt have the power to drive the A/C compressors and move the bus.. (busses like my 78 Superior were sold with these)...a system like thyis would be started up to pre-cool a bus or left running to keep a bus cool while parked.. its not quiet generally.. (wouldnt be campground friendly but out in the sticks would be fine to use)...
if you want quiet and solar (and to wear seeat rags on hot road trips) then you would likely not use this system...
if you dont buy the bus let me know I might buy uit, harvest the A/C for my superior and then re-sell it.. I hate driviing without A/C so I personally would keep it.. but you may not care... a minisplit on solar will keep you nice N cool while parked but not do much on the road..
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05-08-2022, 06:02 PM
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#8
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Bus Crazy
Join Date: Jul 2021
Location: Southern Oregon
Posts: 1,624
Year: 1996
Coachwork: AmTran (Now Navistar)
Engine: DT444E (7.3L) International
Rated Cap: 31,800 pounds
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What is this idea that solar powered A/C can't be effective under way?
A 9,000 BTU A/C i rated for up to 450 SqFt (with 8' ceilings mind you that's about 3,600 CuFt).
A 40' RE or FE bus built out will have about 7.5 x 38' with 6'3" headroom for 1,781 CuFt or roughly HALF the rated capacity.
An efficient 9,000 BTU unit pulls 800W when the compressor is running.
A good solar bank and battery set (or a 100 amp second alternator for the "house" can easily handle that load.
So it really ONLY comes down to whether or not you built out the rig in a way that minimized or removed the amount of drafts.
Prior Proper Planning Prevents Piss Poor Performance so our bus will have near zero drafts other than planned and necessary ventilation (cat box, over the stove, bathroom, optional roof ventilation for mild weather, etc.). The door will be completely reworked to be a single outward opening unit that closes onto effective seals around the entire perimeter. We don't have traditional school bus windows as our rig was originally built as a transit and has coach windows (most of which are being removed).
Bottom line. In a properly built rig, you don't have to keep the inefficient factory A/C if you build properly.
__________________
YouTube: HAMSkoolie WEB: HAMSkoolie.com
We've done so much, for so long, with so little, we now do the impossible, overnight, with nothing. US Marines -- 6531, 3521. . . .Ret ASE brakes & elect. Ret (auto and aviation mech). Extra Class HAM, NAUI/PADI OpenWater diver
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05-08-2022, 08:12 PM
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#9
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,845
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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Quote:
Originally Posted by HamSkoolie
What is this idea that solar powered A/C can't be effective under way?
A 9,000 BTU A/C i rated for up to 450 SqFt (with 8' ceilings mind you that's about 3,600 CuFt).
A 40' RE or FE bus built out will have about 7.5 x 38' with 6'3" headroom for 1,781 CuFt or roughly HALF the rated capacity.
An efficient 9,000 BTU unit pulls 800W when the compressor is running.
A good solar bank and battery set (or a 100 amp second alternator for the "house" can easily handle that load.
So it really ONLY comes down to whether or not you built out the rig in a way that minimized or removed the amount of drafts.
Prior Proper Planning Prevents Piss Poor Performance so our bus will have near zero drafts other than planned and necessary ventilation (cat box, over the stove, bathroom, optional roof ventilation for mild weather, etc.). The door will be completely reworked to be a single outward opening unit that closes onto effective seals around the entire perimeter. We don't have traditional school bus windows as our rig was originally built as a transit and has coach windows (most of which are being removed).
Bottom line. In a properly built rig, you don't have to keep the inefficient factory A/C if you build properly.
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throiw everything you know about square footage out the window... you are driving a bus 60+ MPH in full sunshine if its conventional or FE you have an engine blasting you with heat (no matter how much you try to seal the engine compartment).. even in an RE you have a huge front windshield.. you have a wind push changing the air out rather quickly even with the outside air intake closed... if you are travelling in summer heat and humidity a 9000 BTU solar unit aint gonna touch it.. mounting the unit up front is dumb because most people want to be coolest when sleeping and most builds have the bed in the back.. so very little A/C is going to make it up front..
build whatever you want... lest i forget I guess "real men dont need A/C in the world of ham...".. otherwise build stuff that works...
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05-08-2022, 09:13 PM
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#10
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Bus Crazy
Join Date: Jul 2021
Location: Southern Oregon
Posts: 1,624
Year: 1996
Coachwork: AmTran (Now Navistar)
Engine: DT444E (7.3L) International
Rated Cap: 31,800 pounds
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Quote:
Originally Posted by cadillackid
throiw everything you know about square footage out the window... you are driving a bus 60+ MPH in full sunshine if its conventional or FE you have an engine blasting you with heat (no matter how much you try to seal the engine compartment).. even in an RE you have a huge front windshield.. you have a wind push changing the air out rather quickly even with the outside air intake closed... if you are travelling in summer heat and humidity a 9000 BTU solar unit aint gonna touch it.. mounting the unit up front is dumb because most people want to be coolest when sleeping and most builds have the bed in the back.. so very little A/C is going to make it up front..
build whatever you want... lest i forget I guess "real men dont need A/C in the world of ham...".. otherwise build stuff that works...
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I disagree. Properly designed and built, which includes insulation, sealing off air drafts, providing permanent roof shade with an air gap, and other design criteria, there simply isn't going to be all this solar heating and free flowing air blasting through because we're traveling 60mph.
Our design provides DUAL 9,000 BTU mini splits. One at the top front over the windshield and one in the bedroom at the rear. This provides redundancy as well as the ability to close off an area and reduce the energy needed for cooling. For example, the front can be closed off during driving with a simple curtain to minimize the area requiring heating or cooling while driving. Likewise, the bedroom can be closed off to minimize the electrical load for all night cooling. The bedroom isn't heated because we use an electric mattress pad. The backup being to turn up the rear parking heater.
So, we have redundant systems for both heat and air, the rig will be very much sealed with a rebuilt front door, closed cell foam everywhere but the windows and floor, the floor is sealed and insulated with foam board and that's over the wheel to wheel, side to side, enclosure under the bus.
While most may not consider the entire systematic interrelationships when building, we have. We could cheap out on some stuff but aren't. We'll have 25%+ of our build cost sunk into the off grid electrical alone what with solar panels and mounting, 10+kWh of lithium batteries, Victron controllers, inverter, charger, and monitoring gear, etc.
The A/C is hardly even an challenge.
__________________
YouTube: HAMSkoolie WEB: HAMSkoolie.com
We've done so much, for so long, with so little, we now do the impossible, overnight, with nothing. US Marines -- 6531, 3521. . . .Ret ASE brakes & elect. Ret (auto and aviation mech). Extra Class HAM, NAUI/PADI OpenWater diver
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05-09-2022, 12:40 AM
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#11
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Skoolie
Join Date: May 2017
Location: Gulfport, MS
Posts: 154
Year: 2000
Coachwork: Bluebird All American Re
Engine: Cat 3126
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Not to take sides or stir the pit on this one, but I would love to hear or see a case study on this debate. I have heard this argument several times before which is why I am torn between keeping my original AC or not. It wasn't working when I got the bus but it is all there. I took the inside units out during demo and don't want to put them back unless I need to. Having 4 overhead AC units, 2 road and 2 mini split, is difficult and space consuming not to mention costly if the original bus AC is broken.
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05-09-2022, 02:04 AM
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#12
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Bus Crazy
Join Date: Jul 2021
Location: Southern Oregon
Posts: 1,624
Year: 1996
Coachwork: AmTran (Now Navistar)
Engine: DT444E (7.3L) International
Rated Cap: 31,800 pounds
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Quote:
Originally Posted by bridg73988
Not to take sides or stir the pit on this one, but I would love to hear or see a case study on this debate. I have heard this argument several times before which is why I am torn between keeping my original AC or not. It wasn't working when I got the bus but it is all there. I took the inside units out during demo and don't want to put them back unless I need to. Having 4 overhead AC units, 2 road and 2 mini split, is difficult and space consuming not to mention costly if the original bus AC is broken.
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A true and scientific case study would be difficult as there are so many variables and no two builds are alike.
We are working under the premise of removing drafts by sealing with closed cell spray foam, removing a lot of windows, rebuilding the door into a well sealed single unit with weather stripping, and home style lock, tinting all remaining glass including to the maximum allowed by law in the cockpit. Second is lots of insulation. over R18 in the walls, R 10 in the ceiling, R7.5 to R10 on the floor. And a massive solar array with matching lithium bank. We're starting with 10.24kWh and building the rack to hold another 5.12kWh if that's not enough. Considering we use 14kWh in an average day in our all electric home of 1200 SqFt, we think 10kWh is more than enough for less than 300 SqFt of bus when heat will not be electric and cooking has a choice of gas or electric depending on which needs to be conserved in the particular situation.
But when it's all done and on the road, we'll be reporting on how it's performing. And I'm looking forward to several things.
The first 100F day
The first trip to the overcast coast
The first sub 32F day
__________________
YouTube: HAMSkoolie WEB: HAMSkoolie.com
We've done so much, for so long, with so little, we now do the impossible, overnight, with nothing. US Marines -- 6531, 3521. . . .Ret ASE brakes & elect. Ret (auto and aviation mech). Extra Class HAM, NAUI/PADI OpenWater diver
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05-09-2022, 12:15 PM
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#13
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Skoolie
Join Date: Aug 2021
Location: Santa Fe
Posts: 144
Year: 2007
Coachwork: Thomas
Chassis: 31 ft. HDX
Engine: CAT C7 250 hp
Rated Cap: 36,300 GVW
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Here's what I know about bus A/C.
I have a 2007 Thomas HDX 31 ft Bus, Cat C7 with Allison 6 speed auto.
It has a Carrier rear mounted 120K BTU A/c system that will maintain 60 degree temps inside the bus on a 100 degree day in Arizona -- even if the bus is parked and idling. And that is in un-modified bus form, a white roof and tinted windows. Turn off the A/C and it gets warm inside the bus really quick.
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05-09-2022, 03:43 PM
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#14
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Bus Nut
Join Date: Feb 2022
Location: Midwest
Posts: 267
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Massive insulation would help, as would addressing engine heat. For a front engine, a combination between firewall insulation and ventilation is needed, so a way to draw air out of the engine compartment is needed. A way to do this while the bus is driving is a front skirt, a lip mounted lower than the skirt underneath the front of the radiator mount, and under-engine cover that extends to the front of the firewall. While the skirt should extend to the firewall, it should not be connected to the firewall but should hang underneath. The idea is to create a low pressure area under the engine that draws its air from the engine area so it needs room for air to pass between the under-engine cover and firewall. The skirt will also need to wrap around under to the front of the firewall as much as is feasable. The skirt and lip will create a low pressure area under the bus, the lip will also help force air up and through the radiator, and blocking airflow underneath the engine to the firewall will maintain that low pressure area up to the firewall.
This should force air over the engine and down under the bus, and should draw a considerable amount of heated air away from the driver's compartment. Yes, heat rises but that heat will heat the air over the engine, and that heated air can be made to blow down while retaining its heat. If more heat absorbing air passes over the engine than the engine can effectively heat, then the underhood temps fall.
Unfortunately, for me this is a thought experiment for at least several years (I do things in order, and before I buy a bus I will finish building a place for it to go) but if anyone wanted to give it a try and had a little scrap and time a temp setup could be developed for testing. Measuring would be simple enough as well, assuming that the driver gets hot and sweaty when driving without the air on. Put it on and if the driver doesn't get hot and sweaty, or as hot and sweaty, then it would be successful. If it is successful, something more permanent could be made. All one would need to test is enough metal/wood to build a flat platform to bolt under the engine from the rad support to the firewall without interfering with steering, with a 90 degree lip at the front of the rad support that drops a couple of inches.
My basis for this is the picture below. See the little black spoiler back up under the nose? My brother had a Trans Am many years ago, bought new, and the engine overheated and melted down. He had the dealer install a ground effects kit, but they didn't install that little rubber piece up under there correctly. Just missing 1 inch of drop was enough to keep the air from flowing under the nose and into the radiator correctly, so the air in the engine bay never moved, the fans couldn't pull enough air through the radiator, and the engine finally melted down after several dealer visits that "found no problems." The dealer wound up buying the car back once they figured this out.
https://www.thirdgen.org/tech/images...83_MiniRam.jpg
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