AC compressor removal

[Busjamin]

Earth Temperature Timeline

xkcd.com

9000BC - Last North American Pokemon go extinct Anyone linking xkcd is alright by me.

 

[Mr P]

Climate change....I aluded to something in another topic, I'd put that here now:

I own some land. I rent part of the acreage to a farmer who row crops it, while the rest is wooded and has my home and outbuildings (and rusty vehicles I'm "gonna fix one day"...and now, a bus ). I was approached by a "solar rep" who offered me about 5 times more money than the farmer (farmers recieve some fed subsidies, for crop prices and crop insurance, and some get paid to NOT grow food). SO, I wandered HOW can a solar company afford to rent my land for a factor of 5 times...I dug into the demand and money. The demand is because power companies are mandated (by the EPA) to produce a certain % of their electricity from "green" or "renewable" sources. So, the local power company (and actually the big cities of Lexington and Louisville) were needing solar power to meet those regulations.

Further investigation found that the demand was from the regulations put in place in about 2012. (Obama) The money floating around was from the "Inflation Reduction Act" (which increased inflation). (Biden) (Kinda like the Patriot Act was against patriots, but I digress.) (Bush II).

Another kicker, the rep offered to rent ALL my acreage, when I knew that only about 2/3 was farmable, the rest being trees and my house. When I pointed out his figures were for too much land, he replied that they'd "take out the trees".

SO, whether or not the climate is changing at "this" or "that" rate, two facts are evident. IF I had signed on the line I'd be "rich" compared to what I am, and there would be less food for you poor people. And less clean air.

But I'm still poor. Enjoy your dinner.

(I told the solar guy that I was for solar: he could put panels on all my metal roofs, he declined.)

(I'm not saying "the right" is better in the long run, but dozing trees and planting less food is easy to beat.)



AC, I tore my units out because of space, but I kept the compressors on the engine with hopes that I can use one to power two small evaporators (from cars) that might be adapted into the space that held the factory front heaters. That would be travelling air, mini split for shore air. But those are dreams, not yet even drawn out.

 

[Mr P]

I'm interested in knowing more about why the mini-split is problematic while underway. I can't seem to find a full answer. Sure they are less powerful, but is it really that difficult to mitigate the issues? Mounting dampers for vibration? Shrouding engineered to allow air but not turbulence?

I'm looking at the same problem now. Less powerfull could be fine, if we factor in that there are going to be about 50 less people riding the bus! And the bus is gonna gain insulation under the floor and improved insulation everywhere else. I'm leaning toward about as much AC as my van has which has one compressor powering two evaporators and keeps the same people cool on a hot day.

The guy that posted the themal imager views of his bus here gave us some good info. Beg, borrow, or rent a thermal imager before finishing your insulation to make sure you don't miss a spot.

 

[Cheezewhiz]

I can't say for other setups, but our factory driving AC has solid steel ducts that run the length of the rig.

When it's been going long enough those ducts are cold, driving doesn't matter. It stays nice.

I imagine a mini split isn't going to have the thermal inertia of built-in steel ducting.

 

[Busjamin]

I imagine a mini split isn't going to have the thermal inertia of built-in steel ducting.

My bulkhead ducts are the same. This makes sense. You can feel this effect with a normal car's AC system as it cools down the inside of the dash and ducting.

I guess I just wouldn't expect this 'effect' to have enough impact on the overall cooling, over things like insulation and air distribution.

These are the reasons I have seen NOT to run mini-split on the road:

• Vibrations can interfere with the inner-workings of the unit (Mount with damping?)
• Turbulent air makes the system less efficient (Design an enclosure to mitigate turbulence?)
• Dirty air (Bad mounting location?)
• Convection & air intrusion at speed (Do we really expect that much air intrusion on a decently sealed and insulated bus? It's not a pressure vessel but I'm surprised to hear this is a problem.)
• 12k BTU vs. 50k BTU no comparison (But we cool our buses with mini-splits while stationary just fine, so it can't be that simple)

It seems to me that we should be able to install the system in a way that mitigates these issues and cool the bus just fine on the road...

Idk, I am biased toward finding a way to delete mine so I can reclaim that sweet-sweet bed space and install a rear window.

 

[nikitis]

I'll sum up what we've discovered with Cadillackid who was literally an AC Specialist. He's been quoted "anything under 12k BTU will be wholly insufficient for a bus."

If you have a 40 foot bus you'll likely need 2 head units to keep the whole thing cool because it will leak out through windows etc.

Insulation makes a HUGE difference here. This is why I went with 4 inches of XPS foam for the floor sacrificing height in my bus. A lot of the cool air leaves through the floors of a bus and buses with no or insufficient insulation in the floors loses a lot of the cool air they are generating. 4 inches of XPS will keep most of this in the bus from the floor area. So in essence you can cool with less BTU if you do 4 inches of XPS on the floors, and 3inches of foam insulation on the walls and ceiling. That leaves only windows, your windshield, and doors as a vulnerability for loss.

That much insulation will make a difference with a 12k BTU mini-split. 12k mini-splits are fine to use as replacements but if you mount the condenser under the bus, some units will NOT run if there's too much vibration in the fans. Those models have sensors. Certain brands do not have the sensors and will run the fan regardless. You'll have to do your research on which brands can take some vibrations and which cannot and go with the brands which can take the vibrations. I don't recall which brands do and do not work under vibrations, but if your condenser unit stops operating due to vibration you won't get AC while driving.

There are posts on this forum that mention the brands, but you likely won't find a title of a thread with it, It's been talked about in passing on this forum. If you search the forum by brand name you may find the discussion that way.

 

[ewo1]

These are the reasons I have seen NOT to run mini-split on the road:

• Vibrations can interfere with the inner-workings of the unit (Mount with damping?)
• Turbulent air makes the system less efficient (Design an enclosure to mitigate turbulence?)
• Dirty air (Bad mounting location?)
• Convection & air intrusion at speed (Do we really expect that much air intrusion on a decently sealed and insulated bus? It's not a pressure vessel but I'm surprised to hear this is a problem.)
• 12k BTU vs. 50k BTU no comparison (But we cool our buses with mini-splits while stationary just fine, so it can't be that simple)

It seems to me that we should be able to install the system in a way that mitigates these issues and cool the bus just fine on the road...

Idk, I am biased toward finding a way to delete mine so I can reclaim that sweet-sweet bed space and install a rear window.

All the reason you listed are valid ones but you last reason, the math...it simple. there is no comparison. If your reason is simply recovering space and adding a window, have you considered simply relocating the factory unit?

I agree mini splits would do fine in a stationary unit but when your driving for hours on hot 100+ degree roads, in order to run that mini split you will either need to run a genny or unnecessarily power it from you solar system batteries.

I have 2 busses, one with a/c and the other without. Guess which one gets driven more.... the a/c bus!

 

[Mr P]

I agree mini splits would do fine in a stationary unit but when your driving for hours on hot 100+ degree roads, in order to run that mini split you will either need to run a genny or unnecessarily power it from you solar system batteries.

What is wrong with powering the mini split with an inverter from 12v and using the engine alternator for power? My alternator has pretty high output (it powered about 10 fans/blower motors). Or, if desiring a 24v inverter, add a 24v alternator to the engine to power it?

 

[Janet H]

Mod hat on: Folks, the Skoolie Forum has a "no politics" rule for participants because threads are hijacked, hackles are raised and no one ever changes their minds.

Please keep topics focused on Skoolie and RVing-related challenges and argue about the state of the world elsewhere. Thanks.

 

[Busjamin]

Mod hat on: Folks, the Skoolie Forum has a "no politics" rule for participants because threads are hijacked, hackles are raised and no one ever changes their minds.

Please keep topics focused on Skoolie and RVing-related challenges and argue about the state of the world elsewhere. Thanks.

Respectfully, it's not political. That's the whole point and I hope you take this seriously.

Can I humbly request that you elaborate? I personally would like to know where specifically in this thread lines were crossed. I understand you may not be able to name-and-shame, but I feel like it would help us 'politically interested' folks understand how to conduct this sort of discussion in a way that doesn't require the mod hat. You can't just let some members repeatedly inject their backwards anti-science beliefs while expecting the rest of us to play nice...

From my perspective, it seems that the people who call out and challenge the political injections are triggering the mod response and getting us in trouble. I've noticed this pattern across multiple threads, so I guess I'm wondering why you're not just banning the folks that can't seem to resist politicizing science? Could make your life a lot easier...

Maybe the sticky thread about forum rules could be expanded to make it less ambiguous than "no politics"? I just want clear guidelines. Frankly I don't think it's terribly hard to see who's causing a problem, but I'm not in charge.

 

[ewo1]

Mod hat on: Folks, the Skoolie Forum has a "no politics" rule for participants because threads are hijacked, hackles are raised and no one ever changes their minds.

Please keep topics focused on Skoolie and RVing-related challenges and argue about the state of the world elsewhere. Thanks.

Thank you!
Well said!

 

[ewo1]

Respectfully, it's not political. That's the whole point and I hope you take this seriously.

Can I humbly request that you elaborate? I personally would like to know where specifically in this thread lines were crossed. I understand you may not be able to name-and-shame, but I feel like it would help us 'politically interested' folks understand how to conduct this sort of discussion in a way that doesn't require the mod hat. You can't just let some members repeatedly inject their backwards anti-science beliefs while expecting the rest of us to play nice...

From my perspective, it seems that the people who call out and challenge the political injections are triggering the mod response and getting us in trouble. I've noticed this pattern across multiple threads, so I guess I'm wondering why you're not just banning the folks that can't seem to resist politicizing science? Could make your life a lot easier...

Maybe the sticky thread about forum rules could be expanded to make it less ambiguous than "no politics"? I just want clear guidelines. Frankly I don't think it's terribly hard to see who's causing a problem, but I'm not in charge.

I think the point is that we should be focusing on skoolie related matters here...world issues, climate issues....these are not skoolie topics.

 

[Busjamin]

I think the point is that we should be focusing on skoolie related matters here...world issues, climate issues....these are not skoolie topics.

Of course. I agree. (Edit: Partly agree. Some topics are everyone's topics. Climate change is one that affects us all. IMO raising the subject of climate change is pretty valid while discussing reducing the AC capacity of your bus.)

I want to know why the people dragging each thread into pseudo-scientific territory are being tolerated. By the mods and the members.

 

[AlphaHare]

FWIW - I did a little digging, 1961 is when a lot of weather data collection methodology became standardized globally. The calculation of modern 'average' is generally from 1961 forward plus 20 or 30 years.

And I'll keep to topic and busses from now on. I do appreciate a stress-free community here.

 

[Mr P]

Alphahare, do you think that because standardiztion was accomplished in, say, 1975, that the temp of that year should be set as "normal" or "goal'? I can understand setting that temp as a "standard" in a similar way as setting a "grade" when excavating dirt, but it seems to me that 1975 temp is used more as a way to say "this is how all of earth should be" (sea level, ice cap, ect). I do not see that correlation as scientific.

If I took the temperture of my 30 year old bus engine on a Thursday at 2:15 pm, could that temp be used to accurately tell what the engine's temperature should be? Maybe. Or maybe not. It depends on which Thursday and what the bus was doing. I think that is much like the 1975 temp, it's a very narrow (microscopic) viewpoint.

 

[Rock-N-Ruth]

Hi everyone, I have a 2003 IC 3000 DT466E. I am in the process of removing the AC system and tracing hoses back up to the AC compressors. I believe I have (2) of them. I wanted to double check if it's necessary to remove the compressors or can I just cut it from the hoses? Or is better to remove them? If removal is required will it mess anything up with my current setup (belts, pulleys, engine function) It looks separate- but I wanted to get some advice before proceeding.

Attaching pictures. Thanks!

Hi everyone, I have a 2003 IC 3000 DT466E. I am in the process of removing the AC system and tracing hoses back up to the AC compressors. I believe I have (2) of them. I wanted to double check if it's necessary to remove the compressors or can I just cut it from the hoses? Or is better to remove them? If removal is required will it mess anything up with my current setup (belts, pulleys, engine function) It looks separate- but I wanted to get some advice before proceeding.

Attaching pictures. Thanks!

You can remove the hoses and the condensers to free up space, there is no need to remove the compressor from the engine compartment, it's on a clutch, which won't engage since the system is depressurized.

 

[ewo1]

What is wrong with powering the mini split with an inverter from 12v and using the engine alternator for power? My alternator has pretty high output (it powered about 10 fans/blower motors). Or, if desiring a 24v inverter, add a 24v alternator to the engine to power it?

Yes, all these options are doable and will work...but why reinvent the wheel?
Adding a second 24 volt alternator will be a task, with a price tag attached to it.
running wires and buying an invertor, again, re-inventing the wheel.

Take a closer look at some high end class A units on the road. You will see 4 or 5 a/c units on the roof. Why? Because they can't put out enough BTU to keep you cold when going down the road which is why you will see residential A/C units inside the cargo bays of converted MCI busses.

I am gonna install a mini split on my A/c bus but only for when she is parked and the diesel engine is OFF.

 

[Mr P]

Yes, all these options are doable and will work...but why reinvent the wheel?
Adding a second 24 volt alternator will be a task, with a price tag attached to it.
running wires and buying an invertor, again, re-inventing the wheel.

Take a closer look at some high end class A units on the road. You will see 4 or 5 a/c units on the roof. Why? Because they can't put out enough BTU to keep you cold when going down the road which is why you will see residential A/C units inside the cargo bays of converted MCI busses.

I am gonna install a mini split on my A/c bus but only for when she is parked and the diesel engine is OFF.

My situation is like the OP, so I've been pondering the best way forward. As a mechanic with decades of experience, I understand the "power" of an engine driven compressor. My bus had two units, each with over 6 lbs of r134a. I also see my (bus) seating cap at about 50. My 15 passenger van only has about 2 lbs. Neither vehicle has much insulation.

A big word called "IF"....IF my bus is going to have a shore power A/C system, and have an inverter anyway, then upsizing the inverter enough to cover the mini split while on the road will probably eliminate the need (and complexity) for engine AC.

I mentioned 24 volt engine alternator because....the amp draw of a large 12v inverter gets very large. 24v is an option, but that requires either converting 12 to 24, or just making 24 from the engine. As a mechanic, I understand that delco alternators are available with 24v regulators, probably more affordably than an electronic converter from 12 to 24. Brackets and mounting would be the highest hurdle.

I'm not re inventing the wheel, just pointing out there are more wheels, and some fit better than others. I'm very much looking into a mini split/inverter combo.

 

[nikitis]

I actually agree with this potential. It hasn't been done here that I've observed, but does not mean it could not be done. Make your own bracket and go 24v and see if it will work. 24v inverter + 24v alternator, do you have a 24v battery setup or do they make direct current 24v AC units? basically if you can keep it 24v across the whole chain, or go step down from 24v to 12v is better than 12v to 24v, but I'd think that you wouldn't get much if any at all increase if you still used a 12v AC unit. The step down would be a bottle neck for any gains from 24v.

 

[ewo1]

My situation is like the OP, so I've been pondering the best way forward. As a mechanic with decades of experience, I understand the "power" of an engine driven compressor. My bus had two units, each with over 6 lbs of r134a. I also see my (bus) seating cap at about 50. My 15 passenger van only has about 2 lbs. Neither vehicle has much insulation.

Well, I really don't understand what the OP actual situation is. all I read is that he was simply asking about removing the system and really did not expand into why he wants to remove it.

You say your bus "HAD" 2 systems. Are they already out or simply just not working...
If not working, have you looked into why not?

If it is working, how cold does it get on a 100 degree day when you roll down the highway?

That's the real test, rolling down the road.

What I know is that he is in central Florida. I just left south Florida after almost 30 years and I can tell you this, it gets hot in central Florida...not like Texas but it gets hot!

When I drove my non a/c bus to Texas it was miserable! I was sweaty and dirty and had to open the drivers window and roof vents most of the way. Couldn't open the other windows as there are no more but the bus is insulated.

When I drove my a/c bus (2x now) from Miami to Central Tx, what a difference. Clean, no sweating and very comfortable. This bus is not yet insulated.

I can agree with you 100% on the "Other" ways to power a mini split but I ask myself why would I run the secondary power system, put a load on the invertor and batteries when there really is no reason to go down that path. Again, I agree that it can be done and it will work but to get the same (or close to) of BTU cooling you would need 3-4 mini splits, not one. I'm talking about 12k 120v units.

If the "inverter" method works best for you then so be it. I'd like to take note on how you get it done.

BTW. I posted a link for the service manuals for school bus a/c units. They are not hard at all to service.

Bus A/C SERVICE PARTS LIST

I found this parts list manual which is 428 pages, 15 mb. https://www.mcc-hvac.com/wp-content/uploads/2014/11/T-299PL.pdf If your bus has A/c you can use this to familiarize yourself on all the parts involved so please, SAVE THAT A/C, DO NOT JUNK IT! SERVICE PARTS LIST for SPLIT SYSTEMS...

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