Reply
 
Thread Tools Display Modes
 
Old 11-11-2016, 08:01 PM   #11
Bus Nut
 
AlleyCat67's Avatar
 
Join Date: Oct 2013
Location: Music City USA
Posts: 737
Year: 2005
Coachwork: Thomas
Chassis: Freightliner
Engine: Detroit MBE906
Rated Cap: 72
Looks like that particular one is nonoperational but it does give another idea to consider.

Appreciate the info!
__________________
My bus - Jasmine - External Build Website - YouTube Channel - TN/KY Meetup Group
As a level 1 burglar, Bilbo got a pony when he accompanied the level 60 dwarves on the Smaug the Dragon raid. Those powerlevelers probably invited him solely so he could trigger fellowship attacks for them.
AlleyCat67 is offline   Reply With Quote
Old 11-11-2016, 08:45 PM   #12
Skoolie
 
Alan N's Avatar
 
Join Date: Jan 2015
Location: Gonvick MN
Posts: 247
Year: 1975
Chassis: Gillig
Engine: Cat 3208t/10 speed transmission
I like this thread.
What's the best kind of tubing to use for the long runs on this project?
It needs to be flexible, and cheap would be nice.
Would hydraulic hose work?
__________________
Sufficient unto the day is the evil thereof.
Alan N is offline   Reply With Quote
Old 11-11-2016, 08:49 PM   #13
Bus Nut
 
AlleyCat67's Avatar
 
Join Date: Oct 2013
Location: Music City USA
Posts: 737
Year: 2005
Coachwork: Thomas
Chassis: Freightliner
Engine: Detroit MBE906
Rated Cap: 72
Quote:
Originally Posted by Alan N View Post
I like this thread.
What's the best kind of tubing to use for the long runs on this project?
It needs to be flexible, and cheap would be nice.
Would hydraulic hose work?
Not sure what the price per foot would be on this but it's an option to look at:

Industrial Refrigerant Hydraulic Hose | Gates Corporation
__________________
My bus - Jasmine - External Build Website - YouTube Channel - TN/KY Meetup Group
As a level 1 burglar, Bilbo got a pony when he accompanied the level 60 dwarves on the Smaug the Dragon raid. Those powerlevelers probably invited him solely so he could trigger fellowship attacks for them.
AlleyCat67 is offline   Reply With Quote
Old 11-12-2016, 01:32 AM   #14
Mini-Skoolie
 
Join Date: Oct 2016
Location: Tacoma Wa
Posts: 16
Year: 1995
Coachwork: Genesis
Chassis: International
Engine: DT466
What about using the red dot systems. mostly used in farm equipment and dump trucks. this is just one model.

New RedDot Mack Truck Backwall A/C Unit air conditioner Dump Truck R7830 | eBay
The menagerie is offline   Reply With Quote
Old 11-12-2016, 08:35 AM   #15
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 5,522
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
you use standard Barrier A/C hose like in a car... it is designed to handle the elements.. each hose is a different size depending on the position and capacity.

APU's are great devices... expensive but awesome devices.. im not sure iof 10 HP is enough to spin an alternator and a compressor running 50k plus BTU of A/C or not but it would sure have a shot at it... most APU's are running only about 10k BTU or so for a semi-tractor..

I looked into repurposing a Reefer engine once.. they are diesel.. everything I found was craxy expensive if it ran..

you dont want ot use just 'any hose' as the size must be correct for putting for fittings on... again I recommend BurgaClip fittings because they are easy... I have my DEV bus down here in florida.. I'll try and go take some Pics of the various A/C components I used to give you an idea of what you need...

I'll be in ohio in a week or so where I have sopme spare hose and fittings in the garage where i can take pics of what the pieces look like before assembled..

the issues in types of hoses is not whether they will take the pressure but whether the Inside diameter matches the fitting, and also whether the refrigerant molecules will permeate through the walls of the hose... R-134A molecules are smaller than that of Hydraulic fluid..
-Christopher
cadillackid is offline   Reply With Quote
Old 11-12-2016, 02:09 PM   #16
Bus Nut
 
AlleyCat67's Avatar
 
Join Date: Oct 2013
Location: Music City USA
Posts: 737
Year: 2005
Coachwork: Thomas
Chassis: Freightliner
Engine: Detroit MBE906
Rated Cap: 72
The hose I linked a few posts back was specifically engineered for long runs of refrigerant under high pressure, or that's how I read it anyway.... which probably means it's crazy expensive. I didn't dig too deep because I'm probably gonna do what was suggested earlier and rig a small engine (diesel would be ideal if it's not too expensive, but gas or propane would work too) to run a compressor and hang it somewhere underneath, near the front of the bus so long refrigerant runs won't be an issue. Will just have to come up with a gas tank arrangement that will hold enough to run it for an extended time when I'm on the road.

One advantage of using a diesel engine to run it would be that if you fill up your tank on the truck side of a truck stop you can use reefer fuel to fill the generator tank and not have to pay the fuel taxes on it. (It's the same fuel, just taxed differently.)
__________________
My bus - Jasmine - External Build Website - YouTube Channel - TN/KY Meetup Group
As a level 1 burglar, Bilbo got a pony when he accompanied the level 60 dwarves on the Smaug the Dragon raid. Those powerlevelers probably invited him solely so he could trigger fellowship attacks for them.
AlleyCat67 is offline   Reply With Quote
Old 11-12-2016, 02:36 PM   #17
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 5,522
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
I never knew they fueld REEFERS non tax.. since they are used on-road.. but it does make sense if only the engin e powering the wheels is necessary to pay tax.. of course then you have to maintain a separate tank for the Genny but the savings alone might be worth it..

just think about though the Horsepower requirements for a Bus A/C to work right..
for instance 5 tons (roughly 62000 BTU ) is about 17.5 kilowatts in calculation , up to 20 horsepower... all depends on how much you want to cool.. and as outdoor and indoor conditions change so does the amount of horsepower required to run the compressor... humidity, outdoor and indoor temperature all affect the compressor Load... do some good planning and calculations to go thast route and you wont end up under-powered..
-Christopher
cadillackid is offline   Reply With Quote
Old 11-12-2016, 02:40 PM   #18
Bus Nut
 
Join Date: May 2016
Location: Pacific North Wet
Posts: 827
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
I think you may be right. I looked closer at the cooling capacity of the "stock" Thermo King APU. 12k Btu.

I am still intrigued by the idea of a small diesel that would run a good sized a/c compressor and alternator. Build a little Arduino based throttle controller to vary throttle depending on load. However, the simplicity of coach engine run a/c has strong merit as well.
PNW_Steve is offline   Reply With Quote
Old 11-12-2016, 02:52 PM   #19
Bus Geek
 
Join Date: May 2009
Location: Columbus Ohio
Posts: 5,522
Year: 1991
Coachwork: Carpenter
Chassis: International S3800
Engine: DT360
Rated Cap: 7 Row Handicap
those APU's are designed for a semi-tractor sleeper cab and thats pretty much it.. many of them first generate DC and run the compressor off of DC power.. I know there are some that direct drive a compressor...

no need for special throttle control.. most generators use a very simplistic RPM controller to keep them at 1850 (I think it is) .. one of those type throttle controls would be fine... you dont change the system load by changing the RPM of the engine... most compressors will do their best to try and make up the differenceo n their own... load is changed by how much work is done on the refrigerant.. you always want a good supply of liquid at the TxV inlet.. the TxV will vary the refrigerant flow based on interior heat load... heat load includes humidity removal as well as heat removal... if the TxV goes to its minimum and the coil is in danger of freezing you have the freeze stat trip the compressor clutch out... then the comporessor will re-energize when the coil temp goes back up.. typically generator engine governors are good at responding quickly to load changes.. rarely if ever does a Genny engine take such a quick hit that it stalls.. the A/C compressor cycle in and out will change the engine load quickly.. of course a diesel is nice for this reason too as they typically have lots of torque at low RPM so are less affected by quick load changes..

-Christopher
cadillackid is offline   Reply With Quote
Old 11-12-2016, 03:05 PM   #20
Bus Nut
 
AlleyCat67's Avatar
 
Join Date: Oct 2013
Location: Music City USA
Posts: 737
Year: 2005
Coachwork: Thomas
Chassis: Freightliner
Engine: Detroit MBE906
Rated Cap: 72
Quote:
Originally Posted by cadillackid View Post
I never knew they fueld REEFERS non tax.. since they are used on-road.. but it does make sense if only the engin e powering the wheels is necessary to pay tax.. of course then you have to maintain a separate tank for the Genny but the savings alone might be worth it..
That's exactly how it works. I pulled a reefer trailer during my time with CR England, and truck fuel and trailer fuel were always separate for that reason. Only the fuel used to move the rig down the road is taxed. Fuel used for the reefer, APU, etc, is not taxed.

Quote:
Originally Posted by cadillackid View Post
just think about though the Horsepower requirements for a Bus A/C to work right..
for instance 5 tons (roughly 62000 BTU ) is about 17.5 kilowatts in calculation , up to 20 horsepower... all depends on how much you want to cool.. and as outdoor and indoor conditions change so does the amount of horsepower required to run the compressor... humidity, outdoor and indoor temperature all affect the compressor Load... do some good planning and calculations to go thast route and you wont end up under-powered..
-Christopher
This is still in the planning stages, so thanks for pointing this out. Guess I will have to look at the bigger 18-20 hp engines.

Quote:
Originally Posted by PNW_Steve View Post
I think you may be right. I looked closer at the cooling capacity of the "stock" Thermo King APU. 12k Btu.

I am still intrigued by the idea of a small diesel that would run a good sized a/c compressor and alternator. Build a little Arduino based throttle controller to vary throttle depending on load. However, the simplicity of coach engine run a/c has strong merit as well.
Running it off the bus engine is obviously the simplest option, BUT.... that removes the option of running it while the bus is not moving. You have to idle the bus engine to cool it... a diesel engine that size burns about 1 gallon of fuel PER HOUR at idle. More if you use the fast idle. If you're only planning to use it while on the road this would be acceptable.

A smaller diesel will be much more frugal on fuel.... I don't have hard figures but I figure a gallon will run it 3-4 hours at a guess. Look up a diesel powered generator with the size engine you're looking at and the listed runtime at 50% load will give you a good baseline.

When I was in the military on the honor guard the bus we used had a diesel engine with a separate 3 cylinder diesel engine powering an A/C system. That sucker was loud but it didn't matter in that application. Going down the road or boondocking with no one else close by it wouldn't be an issue but in a campground it might be, so you'd want to find one that runs fairly quietly, and have electric A/C as backup.
__________________
My bus - Jasmine - External Build Website - YouTube Channel - TN/KY Meetup Group
As a level 1 burglar, Bilbo got a pony when he accompanied the level 60 dwarves on the Smaug the Dragon raid. Those powerlevelers probably invited him solely so he could trigger fellowship attacks for them.
AlleyCat67 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 12:12 AM.


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