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-   -   THINK!! before removing your factory A/C! (http://www.skoolie.net/forums/f9/think-before-removing-your-factory-a-c-27952.html)

cadillackid 07-20-2019 04:16 PM

THINK!! before removing your factory A/C!
 
OK.. so the heat wave this week and last has brought about quite a few messages to my inboxes on various social media platforms, sites, and my own email... "HELP! I took out my air conditioning to convert and now im sick on the highway...".. or "what can I do to get my A/C back? I gave away the parts...."...



and a couple other variations..





I get it.. you want to maximize your space and have an aesthetically pleasing conversion.. so the first thing you do is pull out those ugly damn things on the ceiling.. and take out those underbody condensors.. and plop a camper A/C on the roof and that will keep everything cool right? after all you are going to spray foam and do the floors and tint the windows...



YES! to some extenmt you are right.. all of this will help that mini split or camper A/C or 2 keep you cool.. .. when you arent creating a 70 MPH windstorm on a 100 degree freeway with gosh knows how many BTU of solar heat blasting in the front windshields as you roll along... just like you find out pretty quickly in cold weather every single air crack in your bus... heat is no different.. and you are essentially putting your bus into a windstorm everytime you drive it.. not to mention if you are front engine there is engine heat... and lots of it...



a conventional school bus from the factory will have 120,000 - 140,000 BTU of air conditioning... and even at that it will take quite a while to make your bus cool inside.. thats right 10-12 TONS.. enough A/C to cool a 40 employee office..


insulating and fixing up cracks and such will make things MUCH better.. but still you arent likel;y gonna be comfy in a heat wave like this with your genny running the minisplit...



one suggestion is that you incorporate your inside units into your build... I was at a bus rally last weekend and a fellow forum member has built his cabinets for his plumbing systems and pumps.. and his electrical systems and panels below those units.. so they are no longer head bangers or are they going to be ugly... they are integrated into necessary components of his build..



second suggestion is remove one system but keep the other.. most busses do have 2 compressors, condensors and 2 or 3 evaporators.. so keep one system mounted near the front where you and your family ride.. that can give you 60,000 BTU of A/C for driving... if you are willing to part with a little coin you can even buy evaporators that mount inside that useless space above your windshield where the school lights used to be...





I talked to one sad soul who bought a beautiful bus in an auction in arizona with 2 A/C's that kept him very comfortable driving in 115 degree heat last year.. only to pull them out.. hacked up all the wires and hoses and threw away the plastic covers for the evaporators and the screens for the condensors... drove his bus on its first camping trip this week.. with his minisplit on .. ended up with heat exhaustion and cut his trip off and came home before ever making it halfway to his first destination.... now he wants his A/C back... its over $3k in PARTS alone to restore those systems from Trans/AIR... the controls... the many feet of hose, all the fittings, wiring harnesses... those plastic evaporator covers? not cheap... and they are the drain pans for the condensate so they are pretty necessary.... Not to mention the labor involved in putting them back together...



LUCKILY he left the compressors and brackets on the engine.. the bracket set for a DT-466E for dual compressors is about $1000 new from bracketry systems...





im not saying dont take out the A/C.. but im saying THINK befiore you do... and if you want A/C in your bus for driving, then hold out for an auction with air-conditioned busses anbd buy one so-equipped.. bus A/C is expensive to add unless you find someone from category A above thats tossing them in the trash...



DRIVE YOUR BUS IN THE HEAT!!! with said factory A/C turned off.. and I mean really drive it... 2-3 hours in the interstate traffic with a few windows open heading into the summer sun.... then go back home and sleep on whether you deal with a little lost space over and under or wish to sweat... make an educated decision..


obviously there are those who plan to chase the 75 degree weather year round ... or live way up in the mountains and travel mainly there which have no use for driving A/C... or your rig is 99% stationary... or just a weekend warrior to the lake and back.. .


but alot of what i read is "we are going to travel the country... " or "spend our summers on the road all over the place".... etc etc...





-Christopher

Johnny Mullet 07-20-2019 04:43 PM

I could not agree more! This also goes for bus heaters.

cdothill 07-20-2019 04:49 PM

lol truer words couldn't be spoken! i completely agree. the ac is an eyesore-- and literal headache if you keep bumping into it, but DEFINITELY worth integrating into your design if you'll ever be anywhere even "warm."

great post. thanks!

TheHubbardBus 07-20-2019 05:43 PM

I don't think you have any idea how timely a post this is for us.

Our day's task today was pulling the AC units out. And we started thinking exactly like you describe... "Maybe we can just run a rooftop unit while traveling", "look at all the space getting rid of these condensers is buying us", "I keep beaning myself on that front AC".

I'm actually replying before reading your entire post, but from the first 3 paragraphs I know it will be excellent advice & food for thought. So thanks so much for the info. And damn you for making our decisions even harder! (jk) :biggrin:

HazMatt 07-20-2019 05:52 PM

As always, sage advice.
Particularly in this cayenne weather...

JustKip 07-20-2019 06:03 PM

I've been thinking about this quite a bit. Lots of people recommend ripping those out before doing anything else. But I've driven around in a big metal box with no AC, and I can't imagine the dash AC keeping up with demand for even a 100 square foot bus, even if it is insulated. RV rooftop air is nice, but can you use it without being plugged in to shore power?

gs1949 07-20-2019 06:07 PM

Apparently the Auburn WA school district did not see any need for air conditioned buses in 1995, so this is not a decision I have to make. That's one disadvantage to many PNW buses.

cadillackid 07-20-2019 06:30 PM

Quote:

Originally Posted by TheHubbardBus (Post 339239)
I don't think you have any idea how timely a post this is for us.

Our day's task today was pulling the AC units out. And we started thinking exactly like you describe... "Maybe we can just run a rooftop unit while traveling", "look at all the space getting rid of these condensers is buying us", "I keep beaning myself on that front AC".

I'm actually replying before reading your entire post, but from the first 3 paragraphs I know it will be excellent advice & food for thought. So thanks so much for the info. And damn you for making our decisions even harder! (jk) :biggrin:


so do this.. pull them out NICELY. with lots of pics and dont cut the hoses.. and put them aside.. if at some point you deicde "Man I need one of those".. you go put it back in...

TheHubbardBus 07-20-2019 07:52 PM

Quote:

Originally Posted by cadillackid (Post 339258)
so do this.. pull them out NICELY. with lots of pics and dont cut the hoses.. and put them aside.. if at some point you deicde "Man I need one of those".. you go put it back in...

That's exactly what we did today, Chris... labeled all the wires, put a drain pain under the lines as we disconnected them to catch the oil (and took pictures to show how much we lost), etc. Capped off all lines and their female counterparts w/ the fingertips of nitryl gloves cut off and then wrapped w/ electric tape. We implemented much of the advice you gave us directly in a previous thread, Christopher, so again... Muchas Gracias!

Still have the front evap/blower unit in because the refrig fittings were rusted to the point it was impossible to remove them w/o damaging the unit. Every time I walk by I spray them w/ penetrating oil, then try to break them. So far no luck. Any tips on that? It's tricky, because (as you know), the distribution block they screw into is basically secured by the copper tubing on the backside. So I can only crank on those nuts so much before I risk breaking things.

I thought being exposed to the elements the condensers might be tough, but they were the easiest part of the job. No corrosion, no problems.

Rivetboy 07-20-2019 10:10 PM

My 91 blue bird shorty had two trans airs one worked one did not . Left the one that worked in place but have not reconnected the electrical yet to see if it still works after the engine rebuild.The other system that did not work I have removed completely from the bus including the compressor and the evaporator and the condensor. Now I plan to replace the compressor and plan to build this system in a work bench configuration to test and learn and upgrade everything to make it work efficientally. Have a great schematic and plan to upgrade the fans also on the condensor. Planning to use a Harbor Freight 2HP motor to spin the compressor and if that is not enough have a 20 hp Vangaurd V 4 Then, when it blows way cold will swap it out for the one currently in the bus. The plan is to mount the evaporator all the way forward and high in the cab.

All of "you people" that say that this cannot be done ,
Please take a seat over there and the next available service representative will be with you shortly.

Rivetboy 07-20-2019 10:15 PM

[QUOTE=cadillackid
Christopher[/QUOTE]

There is nothing more that needs to be said:thumb:

TheHubbardBus 07-20-2019 10:44 PM

Quote:

Originally Posted by Rivetboy (Post 339306)
My 91 blue bird shorty had two trans airs one worked one did not . Left the one that worked in place but have not reconnected the electrical yet to see if it still works after the engine rebuild.The other system that did not work I have removed completely from the bus including the compressor and the evaporator and the condensor. Now I plan to replace the compressor and plan to build this system in a work bench configuration to test and learn and upgrade everything to make it work efficientally. Have a great schematic and plan to upgrade the fans also on the condensor. Planning to use a Harbor Freight 2HP motor to spin the compressor and if that is not enough have a 20 hp Vangaurd V 4 Then, when it blows way cold will swap it out for the one currently in the bus. The plan is to mount the evaporator all the way forward and high in the cab.

All of "you people" that say that this cannot be done ,
Please take a seat over there and the next available service representative will be with you shortly.


That's awesome, Rivet. I might have some questions for you.


One of the questions I was going to ask the shop that evac'd our systems is if they could bench-test each component as a stand-alone item, so we wouldn't waste $$ & time putting everything back together just to pull it apart again.

TheHubbardBus 07-24-2019 10:10 AM

IMO this thread, or at least Christopher's first post, would be a great sticky in the heating & air subsection.

HazMatt 07-24-2019 10:27 AM

^
Seconded!
The motion passes.
Who's got the Gorilla Glue..?

cadillackid 07-24-2019 11:26 AM

most times the biggest issues with these are Leaks and people cheaply trying to "band aid " leaks by charging can after can of Dye and stop leak into a system..



A/C systems work on the principal of making the "freon" changing from a gas to a liquid and back again.. the Dye, air,oil , moisture, stop leak. are all considered non-condensables. and wont change back and forth.. that stuff in the pipes means less capacity to cool..



but individuals and even maint techs at schools pump ounce after ounce or can after can of that stuff in there.. a single can of 134A with Dye in it will combine with the oil and you never need another one in it unless you flush the system.. a single can of 134a with stop leak is all you need.. if that doesnt fix it then the leak is bigger and needs repaired properly. by locating it and making a repair..



case and point was my TransAir system in the red bus worjed when I got it.. on a 90 degree day I had 56-59 degree air from the vents.. seems nice N cool.. the unit is in the back of that short bus. so I was a little warm up front but was like "thats normal".. when I checked the pressures.. my high side gauge needle jiggled back and forth.. which is a sign that there was liquid in the pipes.. I shouldnt have liquid at the discharge of the compressor.. only gas.. so I evacuated, flushed, cleaned, replaced a couple weak motors.. ran a micron level vacuum, pump.. fixed a very minor leak, and recharged.. last week the heat wave was 100 outside and dewpoint 78.. heat index 112.. I was pushing 40 degrees at the vents.. even in the driver seat I was plenty cool.. and a couple people riding with me said "dude its freezing in here"...



rivet - on the one in your bus that works you could likely clean the coils, blower wheels, and replace any motors that needbe.. then evacuate and Flush the whole thing .. and replace with the nice re-furb evaporator on your bench to the front and recharge with the rated weight and amount of oil .. it will likely be ice cold without removing the lines and condensor..



bench testing is a great way to learn about these systems... just remember orientation of the components is important for oil return and circulation.. you can run for short times.. ie bench testing for an hour or so.. but i wouldnt "burn-in" a system overnight unless the condensor and evaporator and comopressor are set up in the orientation they would be in the bus

PNW_Steve 07-24-2019 11:52 AM

Hey Christopher,

You mentioned stop-leak. Are the current products available OK to use?

The last time I tried a/c stop-leak it did not fix the leak so I took it to the local shop. They scolded me severely for using the stuff and told me that it caused them additional work which they felt compelled to Bill me for.

Thanks

cadillackid 07-24-2019 01:51 PM

stop leak is always a "stop-gap". but a small amount is OK in my book..just never try it more than once or put in more than one can of 134a which also contains stop-leak..



I never use those jkits that say "134a with cooling booster, oil, and stop leak..".. those are the ones that charge in all kinds of non condensables...



some of that stuff is designed so it "thickens" when it hits air.. so its a nice very thin liquid in the system mixed with oil and state-changing refrigerant.. when it Leaks out it thickens and plugs the hole... in very small concentrations it wont hurt anything as its mixed in... but lets say your system already has air in the lines because someone didnt evacuate it correctly.. or it breaks and is torn apart leaving things exposed.. a small amount of that stuff mixed in likely wont make a huge deal.. butthose that charge can after can of that stuff in increase its concentration. and next thing you know.. a system gets opened to replace a bad part.. and the unsuspecting repair tech puts it together, evacuates, and recharges with normal 134a and finds the TxV gunked up or clogged,,, wierd flow... high head - low suction.. and he gets pissed like your tech above that says "never use stop leak!"..
-Christopher

cadillackid 07-24-2019 01:53 PM

oh and P.S. Ive been that tech which has found many ounces of this stuff in a system that nuked a brand new compressor in less than a month..

Native 07-25-2019 01:46 AM

Always a pleasure reading your posts, Christopher!

OrionsComfortBus 07-25-2019 03:05 AM

Great post!

I have a appointment scheduled to have my 2 systems checked out. I suspect the front unit has a leak. Its output is not cooling as well as it did when it was first fixed. I am going to ask them to replace ALL the old freon lines, test the rear evap and condensor for leaks, 2 new compressors and maybe that will keep the interior cool(er) than sweating buckets before the AC was fixed.

I have a suggestion. Get your windshield tinted/covered with "Heat Blocking" film. That alone has made such a huge difference. It was pricey $500+ but nearly stopped the greenhouse effect in the drivers area. Its nearly clear so it will not effect night driving PLUS the reduction of UV exposure means less of a chance of getting skin cancer. Any little bit helps.


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