I am in the process of building my MCI 102c3. I haven't gotten to the wiring stage. I have done a bunc of reading on mini split system. What is hard to find is a conversation specifically about wiring a 220v mini split. I would like to know your thoughts specifically about how to wire bus to handle a mini split ac for 220v. I have a 12.5kw generator, Zantrex SW3012 inverter. The inverter is only 120 volt capable.
I was going to use one of these with a 240 v split but ended up using a 120 v split so I could use it off the bus alternator when driving
https://www.wholesalesolar.com/2500182/outback-power/inverter-accessories/outback-power-fw-x240-auto-transformer
big and heavy
dave
It doesn't seem to change anyone's thinking, and it doesn't seem to matter to them, that THERE IS NO 220 VOLT IN 60 HERTZ in America! It is 120v or double that to two legs and a ground, or 240 volts. Once you get modern, it helps to understand voltage in our USA buses so novices can figure things out.
Wow! My Grandma used to say "if you don't have anything nice to say, don't say it at all." No need to comment if you don't want to be helpful. How about giving some advice to us novices rather than being critical. We are all just trying to figure things out. I thought that's what this board is all about. Buswarrior was right when he said in another thread that this forum is going the way of social media. To quick to poke fun and act superior. I guess I know what he meant now.
Quote from: Geoff on October 02, 2018, 04:45:58 PM
It doesn't seem to change anyone's thinking, and it doesn't seem to matter to them, that THERE IS NO 220 VOLT IN 60 HERTZ in America! It is 120v or double that to two legs and a ground, or 240 volts. Once you get modern, it helps to understand voltage in our USA buses so novices can figure things out.
Sledhead
I was going to have a three zone ac. Your 120 must only be one zone, correct? How do you cool the rest of the bus?
Quote from: sledhead on October 02, 2018, 04:08:03 PM
I was going to use one of these with a 240 v split but ended up using a 120 v split so I could use it off the bus alternator when driving
https://www.wholesalesolar.com/2500182/outback-power/inverter-accessories/outback-power-fw-x240-auto-transformer
big and heavy
dave
This is over simplification but, assuming the source 50A service is wired correctly, you will have 240V available. If you wire your main electrical panel just like a standard house panel, you will have 240V available from the panel. You then need to wire your mini split to a double breaker and you will be in business. The problems with all of this is first, not all 50A sources are wired correctly. Some older campgrounds cheat and wire BOTH sides of the 50A receptacle to the same leg of power meaning you will only have 120V no matter what you do. Another problem would be you need a 240V inverter if you run everything through it, and that brings a whole 'nother set of problems.
This simple basic wiring scheme worked for me:
12K, 240V generator and 50A shore power wired to the LINE side (L1,L2, L3) of 2, separate, 3 pole, 100A contactors used as a transfer switch. They are controlled by a double pole double throw switch (ON-OFF-ON, labeled SHORE-OFF-GEN)
Both LOAD sides (T1, T2, T3) of the contactors are wired to your main panel. All heavy loads (ACs, electric heaters, electric ovens, AC feed to refrigerator, whatever you don't want to run off your inverter) are run off this main panel. Try to split the loads as evenly as possible between the 2 feeds.
The 120V IN to the inverter is run from the main panel.
The 120V OUT from the inverter is run to a secondary panel.
All of the small 120V loads (TVs, computers, receptacles to charge phones, any 120V load that you want to run while on battery power only) are run from the secondary panel.
This setup will give you 120V where you need it and 240V IF it is available from what ever source your are plugged into or when the generator is running.
YRMV
TOM
There's good reason to use 110 and 220 in busnut conversations, and especially when labeling stuff in the coach because of typos or partial label losses.
You aren't owning that coach forever... Someone else will have to deal with faded labels...
We have 12/24 volts..
Too easy for labeling trouble if you use 120/240.
12/24... 11/22... 10/20...
These are the things that in history sink ships, or otherwise cause grief.
As for the question, using a transformer to make your 240 gives you more freedom in accessing campground power, so long as your mini-split doesn't suck back more juice than is available...
Maybe $100 IIRC? I have one lined up in the bookmarks on the other computing device...
Dead simple, step-up transformer. 120 to 240
Happy coaching!
Buswarrior
And there seems to be lots more failures of generators wired for 120/240 and then tried to balance, than wiring them for straight 120.
Pretty hard to get them to balance in a conversion, too big percentages, too small load, etc etc.
Anecdotal from all those peeps that piled onto the mobile command unit bandwagon, post 9/11, and kept on having trouble over and over...
I don't have government ca$h to keep mine going...
Happy coaching!
Buswarrior
I would used 3 mini splits if I were doing things that way. I like redundancy. I have 3 roof tops now and that means if one quits, I'm still cool. Also, I have camped in places that only had 20A service. I could still run one AC.
TOM
I can't complain about mine. It failed after 33 years and 1251 hours. I just put a new head on it & I'm back in business.
TOM
That is the way I originally had thought about it, using 3 separate 120 systems. My problem is where to put the three outdoor units.
Quote from: oldmansax on October 02, 2018, 05:26:04 PM
I would used 3 mini splits if I were doing things that way. I like redundancy. I have 3 roof tops now and that means if one quits, I'm still cool. Also, I have camped in places that only had 20A service. I could still run one AC.
TOM
So rather than using my generator or shore power to bring in 240 I should use a transformer? That would solve the problem of shore power wiring that can't support 240. I would hate to have 50 amps at the campground and still have to use the generator for the ac.
Quote from: buswarrior on October 02, 2018, 05:13:02 PM
There's good reason to use 110 and 220 in busnut conversations, and especially when labeling stuff in the coach because of typos or partial label losses.
You aren't owning that coach forever... Someone else will have to deal with faded labels...
We have 12/24 volts..
Too easy for labeling trouble if you use 120/240.
12/24... 11/22... 10/20...
These are the things that in history sink ships, or otherwise cause grief.
As for the question, using a transformer to make your 240 gives you more freedom in accessing campground power, so long as your mini-split doesn't suck back more juice than is available...
Maybe $100 IIRC? I have one lined up in the bookmarks on the other computing device...
Dead simple, step-up transformer. 120 to 240
Happy coaching!
Buswarrior
On my ex bus the stove was 220v a lot of parks the stove never worked unless I ran the generator.Finding a location for the condenser where it can have good air circulation without giving up to much space is challenging,then I read where people can hang meat with1- 9,000 btu split unit in a 40 ft bus
Quote from: luvrbus on October 02, 2018, 06:42:43 PM
Finding a location for the condenser where it can have good air circulation without giving up to much space is challenging,then I read where people can hang meat with1- 9,000 btu split unit in a 40 ft bus
Hey Clifford, I read somebody was getting 13MPG in an old MC7 too....... LOL!
TOM
Is it possible to mount the outdoor unit inside the rear cap or even on the outside like this guy?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1299.photobucket.com%2Falbums%2Fag79%2Fpastorjared%2Fimage_zps2exm94rr.jpeg&hash=440322075169864a302b8e9e8e3938c92be95972) (http://s1299.photobucket.com/user/pastorjared/media/image_zps2exm94rr.jpeg.html)
Quote from: Jcparmley on October 02, 2018, 05:40:00 PM
So rather than using my generator or shore power to bring in 240 I should use a transformer? That would solve the problem of shore power wiring that can't support 240. I would hate to have 50 amps at the campground and still have to use the generator for the ac.
making 50 amp 2 pole is going to eat a bunch of whatever the power company sends to the RV pedestal.
not sure it can service anything but he transformer.
now what do you do ?
PS over simplified, just because :)
Quote from: luvrbus on October 02, 2018, 06:42:43 PM
On my ex bus the stove was 220v a lot of parks the stove never worked unless I ran the generator.Finding a location for the condenser where it can have good air circulation without giving up to much space is challenging,then I read where people can hang meat with1- 9,000 btu split unit in a 40 ft bus
I find my 9,000 BTU unit works like that ... in the bedroom. 12,000 in the living room and 18,000 over the driver. 5,000 watt transformer off the Trace 4024 or switch it's plug to 240 vac outlet off the panel when I have 50 amp service.
You could mount two on there and fabricate a nice fibreglass shroud that would enclose all but the ventilation area.
I wonder if that setup would work ok going down the road with the swirling airflow around it.
I had a 120 v split up front and a 13.5 k roof shaker in the rear if needed but hated to use it . The coach was spray foamed and had a lot of insulation all around . I still have the transformer but sold the M C I .
In the Featherlite I have 3 roof shakers and miss the split unit + the insulation is not as good as the M C I . As every thing is working ok now I can't see replacing it with splits
I had the outside unit under the 1st bay on the driver side with a booster fan that blew down through the floor to keep the a/c cool with fresh air
dave
Geoff is correct. 110-220 volt is for 50hz. 120-240volt is for 60hz. It's too bad we didn't also adopt the 50hz since more of the world is on 50hz. At 50hz the generator would only run at 1,500 or 3,000rpm.
I wired my bus straight 120v. Also the generator is wired straight 120v. Then I don't have to worry about "balancing the load" between the two legs of electricity. Granted, that means I only have 50amps at the campsite (one leg only) but 6,000 watts is more than enough to run three A/C's if needed.
Stick with 120v splits. You can still get 12,000btu at 120v. Then run one in front, and one in back. You might want to run a third-I have three roof mount 13,500btu A/C's. I seldom have to use the third, but is sure nice to have when needed. Good Luck, TomC
I'm also often irritated by imprecision in electrical nomenclature, but that's probably because I had to get it right every single time in school, and it's stuck with me. I still can't for the life of me remember the difference between "grounded" and "grounding" conductors without looking it up, which brings me to my point. A step up transformer is the obvious solution to 240 VAC from a 120 VAC source, but if your 240 VAC appliances actually need 120-120 with neutral supplied as well, bonding the center tap on the secondary of the transformer becomes problematic. In a building, you can treat the transformer as a new source, ground and bond at that point, with a new primary ground. I would hate to install that in a bus and expect the next guy to know what was happening.
I am not at all opposed to running 240VAC mini-splits in a bus. I would do it with a 50 amp power pole connections (and hope that all the camps are wired correctly, they are not), a 240/120 VAC generator and a similar 240/120 vac stacked inverter system - all with properly grounded and bonded neutrals, and tied together with appropriate switching systems. Otherwise, just stick with 120VAC Mini-splits. The new ones draw so little current that 120 VAC is completely appropriate, until you get into two or three zones and all of that.
Oh my I just looked at a mini split in LOWES it was 115/230 volts ;D
We are learning a lot about you here, JC. If you were in a classroom, and the teacher corrected you for the important misuse of voltage terms, would you denounce the teacher by using Gramma says... or comparing it to social media, or any other forms of attack on the messenger rather than accepting you made a mistake? I don't need you, however you need a lot of help on your bus but it won't be from me.
--Geoff
Quote from: Jcparmley on October 02, 2018, 04:56:18 PM
Wow! My Grandma used to say "if you don't have anything nice to say, don't say it at all." No need to comment if you don't want to be helpful. How about giving some advice to us novices rather than being critical. We are all just trying to figure things out. I thought that's what this board is all about. Buswarrior was right when he said in another thread that this forum is going the way of social media. To quick to poke fun and act superior. I guess I know what he meant now.
Quote from: luvrbus on October 03, 2018, 08:03:45 AM
Oh my I just looked at a mini split in LOWES it was 115/230 volts ;D
Yes, but a 115/230 works on a 120/240v 60 HERTZ system, whereas 110/220 is a 50 Hertz system. My son was trying to put a 120 to 24v transformer in his house furnace, and this transformer would work on 50 or 60 HERTZ. He didn't read the instructions, hooked it up for 110/50 Hertz, and burned up the transformer.
Quote from: Jcparmley on October 02, 2018, 04:56:18 PMWow! My Grandma used to say "if you don't have anything nice to say, don't say it at all." No need to comment if you don't want to be helpful. How about giving some advice to us novices rather than being critical. We are all just trying to figure things out. I thought that's what this board is all about. Buswarrior was right when he said in another thread that this forum is going the way of social media. To quick to poke fun and act superior. I guess I know what he meant now.
JC, please take it in context. What Geoff was saying is correct -- and there has been a lot of grief generated by not properly using electrical nomination. There are many 220V systems in the world that are *nothing" like American 240V systems; many shady overseas "mail order" places will happily sell you one of the "International" 220V systems and have it delivered to your door -- but those systems won't work when fed with N. American power and/or they'll let a lot of smoke out.
I've worked with Geoff on this site for over 10 years. He's knowledgeable and scrupulously correct about describing what he's talking about and careful with terminology. I'm sorry that you took his tone to be critical -- I read it as describing carefully some important details that need to be understood. If anyone doesn't understand the difference that he was describing, that's a good sign that that person should go back to basics and learn the different systems from the ground up. When someone is dealing with mini-splits (and bus wiring in general), it makes a lot of difference.
Someone noted that a "big box" store quotes a mini-split as being specified as being "115V - 230V". I'm guessing that that system in actually a N. American 120V - 240V system, but it sure appears that "Engrish as she is speakened in Shanghai" is letting uncertainty get in the picture in that case.
Sorry Geoff
I was in a rather foul mood the other day. It was a simple mistake of terms. Reading the specs on the unit and it said the voltage needed was 220/240. We are all in the same boat trying to learn from this forum. In a way we are all novices when it comes to certain parts of the bus conversion process. Some are great at HVAC, others are great at electrical, plumbing, wood working, mechanical, welding, etc. My point is, we go to the forum to get help from those that know more about the stuff we know less about. We give advice and take advice. It gets tiring when reading posts where people argue instead of just letting it go. So for my part please excuse my rant and know that I apologize.
Quote from: Geoff on October 03, 2018, 08:13:24 AM
We are learning a lot about you here, JC. If you were in a classroom, and the teacher corrected you for the important misuse of voltage terms, would you denounce the teacher by using Gramma says... or comparing it to social media, or any other forms of attack on the messenger rather than accepting you made a mistake? I don't need you, however you need a lot of help on your bus but it won't be from me.
--Geoff
Yes, I understand The reason I come to this forum is because of the sound advice I get from you all. I appreciate that Geoff was tying to help. It's hard to discern tone in these boards.
Quote from: Oonrahnjay on October 03, 2018, 08:25:51 AM
JC, please take it in context. What Geoff was saying is correct -- and there has been a lot of grief generated by not properly using electrical nomination. There are many 220V systems in the world that are *nothing" like American 240V systems; many shady overseas "mail order" places will happily sell you one of the "International" 220V systems and have it delivered to your door -- but those systems won't work when fed with N. American power and/or they'll let a lot of smoke out.
I've worked with Geoff on this site for over 10 years. He's knowledgeable and scrupulously correct about describing what he's talking about and careful with terminology. I'm sorry that you took his tone to be critical -- I read it as describing carefully some important details that need to be understood. If anyone doesn't understand the difference that he was describing, that's a good sign that that person should go back to basics and learn the different systems from the ground up. When someone is dealing with mini-splits (and bus wiring in general), it makes a lot of difference.
Someone noted that a "big box" store quotes a mini-split as being specified as being "115V - 230V". I'm guessing that that system in actually a N. American 120V - 240V system, but it sure appears that "Engrish as she is speakened in Shanghai" is letting uncertainty get in the picture in that case.
LOL I thought this only happen in politics I heard the stuff called 120/240, 115/230 or 110/220 I guess mine is 115/230 in the shop every leg is 115 volts
I tend to "shoot my face off" on occasion and that works OK on political boards and discussion groups where you don't really care what others think of you.
But on occasion when I feel the "urge" to say something sarcastic on this board I alway remind my self that I may (probably) will need some help on occasion and the last thing I want is for people on here to say "he's an @$# and I'm not going to help him". I'm sure EVERYONE on here who has a bus has, at one time or another, requested help.And, if you really need to make a comment that someone may take the wrong way, imojies :) ;) :D ;D >:(are a great help.
We need more emjois here
http://www.emojimeanings.org/asshole/
Yes you are right. I apologize for my tone.
Quote from: Fred Mc on October 03, 2018, 01:06:43 PM
I tend to "shoot my face off" on occasion and that works OK on political boards and discussion groups where you don't really care what others think of you.
But on occasion when I feel the "urge" to say something sarcastic on this board I alway remind my self that I may (probably) will need some help on occasion and the last thing I want is for people on here to say "he's an @$# and I'm not going to help him". I'm sure EVERYONE on here who has a bus has, at one time or another, requested help.And, if you really need to make a comment that someone may take the wrong way, imojies :) ;) :D ;D >:(are a great help.
Quote from: luvrbus on October 03, 2018, 10:33:04 AM
LOL I thought this only happen in politics I heard the stuff called 120/240, 115/230 or 110/220 I guess mine is 115/230 in the shop every leg is 115 volts
Most utilities that I have been tied to provided 125/250 Volts, according to my Fluke, further complicating the whole voltage debacle. ::)
The confusion lies in the fact that the US started with a 110v/220v system when Edison first put wires in the streets. It was later upped to 112v-117v with 117v becoming the standard after WWII. In 1967 the standard voltage in US home became 120v/240v. (https://en.wikipedia.org/wiki/Mains_electricity)
Richard, we should get together sometime. I am just west of Madison. I'm sure you could give me quite an education on bus stuff.
Quote from: richard5933 on October 03, 2018, 03:55:08 PM
The confusion lies in the fact that the US started with a 110v/220v system when Edison first put wires in the streets. It was later upped to 112v-117v with 117v becoming the standard after WWII. In 1967 the standard voltage in US home became 120v/240v. (https://en.wikipedia.org/wiki/Mains_electricity)
Richard
Is there a service station in the general area that knows busses well enough to diagnose the OTR ac system? I'm not sure who in the Madison / Milwaukee area knows busses.
Quote from: richard5933 on October 03, 2018, 03:55:08 PM
The confusion lies in the fact that the US started with a 110v/220v system when Edison first put wires in the streets. It was later upped to 112v-117v with 117v becoming the standard after WWII. In 1967 the standard voltage in US home became 120v/240v. (https://en.wikipedia.org/wiki/Mains_electricity)
Quote from: Jcparmley on October 03, 2018, 04:28:53 PM
Richard
Is there a service station in the general area that knows busses well enough to diagnose the OTR ac system? I'm not sure who in the Madison / Milwaukee area knows busses.
Lakeside International in Milwaukee has a very good a/c tech. They replaced the compressor on our bus. They do a lot of work on buses.
There has got to be a place nearer to you though.... I just checked and see that Lakeside has a location in Madison. Give them a call.
Quote from: chessie4905 on October 03, 2018, 02:06:16 PM
We need more emjois here
http://www.emojimeanings.org/asshole/
Where the hell is the "like" button this forum? ;)
Awesome. Thanks for the referral.
Quote from: richard5933 on October 03, 2018, 04:43:11 PM
Lakeside International in Milwaukee has a very good a/c tech. They replaced the compressor on our bus. They do a lot of work on buses.
There has got to be a place nearer to you though.... I just checked and see that Lakeside has a location in Madison. Give them a call.
Where ever you take it for service, bring your service manual and parts book. They likely won't have them and they'll be very helpful. Especially for a/c, knowing the factory settings is key.
Quote from: richard5933 on October 03, 2018, 03:55:08 PMThe confusion lies in the fact that the US started with a 110v/220v system when Edison first put wires in the streets. It was later upped to 112v-117v with 117v becoming the standard after WWII. In 1967 the standard voltage in US home became 120v/240v. (https://en.wikipedia.org/wiki/Mains_electricity)
Yes, the standardized modern reference is 120V/240V, for the ordinary current supplied in N. America (and some other countries in the world). .
Yes it is supposed to be 120/240v. But-reading from a volt meter can misleading. Many outside forces can lower that line voltage to appear like 115/230v. What starts as one voltage at the generating plant, may not necessarily end up as the same at your house. Even with a step down transformer on the pole a few houses down, wire size, if your neighbor is using electricity, etc can lower your voltage meter reading. Good Luck, TomC
I was a campsite where you were lucky to have enough 120/30 amp power to run one roof air. But I was able to run two roof airs by using my Trace SW2512MC. When the second air would kick on, the inverter would instantly supply power from the battery bank and after that, start charging again. Love it. No brownouts with the Trace.
When and if I have to replace the Trace inverter, I will have to go for the Magnum Hybrid that does the same thing (I hope!).
P.S. JC and I are okay .
Geoff
Do you use roof air or mini split?
Quote from: Geoff on October 04, 2018, 01:50:44 PM
I was a campsite where you were lucky to have enough 120/30 amp power to run one roof air. But I was able to run two roof airs by using my Trace SW2512MC. When the second air would kick on, the inverter would instantly supply power from the battery bank and after that, start charging again. Love it. No brownouts with the Trace.
When and if I have to replace the Trace inverter, I will have to go for the Magnum Hybrid that does the same thing (I hope!).
P.S. JC and I are okay .
Yep Geoff they will kick in. We run 2 big Coleman on 30 Amp and if we use coffee pot or something else our 4024 Hybrid kicks in to take up any needed extra. :)
I run three Coleman Mac 15k BTUs. Two have heat pumps. I don't want to use my bays for A/C split units.
Since all three are 15 k, how does the regular model compare to the heat pump version. Which do you like better? I plan on replacing my front one with a 15 k and can't decide which one to get.
Today, the heat pump version, provided it is a new, modern refrigerant model, and not some hold-over to older tech...
More heat/cooling often with less power consumed, important for those living on the edge of power management.
The dehumidify feature found on some saves the busnut turning on both AC and furnace on one of those damp days that the coach won't dry out, too cool for AC, too warm for the furnace.
Those old stories about "heat pump" models do not apply to the new ones.
happy coaching!
buswarrior
Quote from: chessie4905 on October 05, 2018, 07:33:50 PM
Since all three are 15 k, how does the regular model compare to the heat pump version. Which do you like better? I plan on replacing my front one with a 15 k and can't decide which one to get.
My Coleman's are 15 years old, so the new ones may not have the few issues I have. First of all, the heat pump units do not put out as cold of air as the one unit without the heat pump. While this is a fact, the heat pump units still put out adequate cold air when in A/C mode.
The only issue I have with the heat pumps, is that they don't produce heat right away-- I have to turn them on and off several times to get the reverse flow moving to produce heat. But when working they put out great heat. I should add I seem to be the only one who has this problem.
--Geoff
When shopping for a Mini-split heat pump, look for the higher end inverter motor units. They use inverter technology to drive the compressor and evaporator motors with variable frequency three phase 240 volts so they are extremely efficient, run the fan motors and compressor at as low a speed as required for the load at hand. I have a 12K btu model in my bedroom that I have to look at the light to see if it's on it's so quiet, and it runs between 1 and 2 amps most of the time. They do take a minute or so to stabilize pressures to produce heat after they turn on, but no more-so than when in cooling mode. In selecting a unit for home use you look for the heat load required for heating, since the temp delta is usually far larger when heating than when cooling - 25 degrees F to 70 degrees F for a 45 degree delta, compared to 95 degrees to 75 degrees when cooling for a 20 degree delta. There is more to it than that, but the heating BTu's are usually a lot more than the cooling BTU's, so I have far more cooling capacity in my house than I need, and just enough heating. I think that would be far more equal or even reversed for a bus.
Brian
I have 2 old style roof a/c with the heat strip . on heat it is warm and fast but the first time you turn it on you smell the crap burning off the heat strips . the newer a/c we have in the bed room has the heat pump and DW hates the on off cycle of the compressor . so if needed we use the front 2 units for heat .
the new a/c heat pump split unit in the house is amazing for a/c we use the dehumidification system most of the time as it is so quite inside and outside you can't tell it is on . I have not tried the heat pump yet
dave
Today I purchased a brand new semi air deflector for only 150 dollars. It's in perfect shape. My plan build a shelf on the back of the bus out of steel and steel mesh and mount two mini split units. I will use the wind deflector over the shelf. The shelf will allow airflow from the bottom and perhaps I will cut vents out of the wind deflector to make sure there is enough air flow. I could even put a air scoop on the top and will raise above the roof a few inches such as a ram air hood would do. I posted a pic of an old bus with a air scoop like the one I envision. For only 150 dollars I thought it was worth a shot to try. What are your thoughts?
Quote from: Jcparmley on October 02, 2018, 07:21:10 PM
Is it possible to mount the outdoor unit inside the rear cap or even on the outside like this guy?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1299.photobucket.com%2Falbums%2Fag79%2Fpastorjared%2Fimage_zps2exm94rr.jpeg&hash=440322075169864a302b8e9e8e3938c92be95972) (http://s1299.photobucket.com/user/pastorjared/media/image_zps2exm94rr.jpeg.html)
This is just a rough example but it might look something like this.
You will have to pay close attention to build-up of debris/oil in the unit's fins.
Everything that goes under the bus, curls up and coats the back of the bus, dist, and anything that drips from the coach.
You've seen the oily backs of crappy charter coaches and some conversions?
Happy coaching!
Buswarrior
That's a good point. I didn't think of that. I wonder if I place louvers on bottom if that would help. Any suggestions on how you all would do this would be great.
Any reason to not stick the thing in a bay? Seems awfully exposed to potential damage hung on the rear of the bus like that.
Inside the rear cap would make more sense to me.
I am planing on using three mini splits. Each one will be 12k. The first unit will be above the windshield with the outdoor unit in ac bay. The second unit will be in the middle of the coach where the bunk beds and bathroom is with the outdoor unit on the back. The third unit will be in the bedroom with the outdoor unit on the back. I thought about putting the two units inside the rear cap but I believe I read on this forum that there wouldn't be enough air flow. Do you think two units can be placed under the rear cap? That would be ideal if it would work.
Quote from: richard5933 on October 16, 2018, 11:26:13 AM
Any reason to not stick the thing in a bay? Seems awfully exposed to potential damage hung on the rear of the bus like that.
Inside the rear cap would make more sense to me.
I have a 18,000 btu unit over the driver and on a warm day (80 to 90 degrees) driving into the sun it is just keeping up. However my bus is a Neoplan Cityliner and the whole front is glass. Like these
https://www.google.com/search?q=neoplan+cityliner&hl=en&tbm=isch&source=iu&ictx=1&fir=hn5YVKscHF9oaM%253A%252CQrgO_CohKaxOyM%252C_&usg=AI4_-kQcvWbkaQc_qAqTpieviAkJQSgXLQ&sa=X&ved=2ahUKEwjomcj83oveAhXcFjQIHZs9BvQQ9QEwBXoECAUQDA#imgdii=VQRyy3YegzzT7M:&imgrc=hn5YVKscHF9oaM: (https://www.google.com/search?q=neoplan+cityliner&hl=en&tbm=isch&source=iu&ictx=1&fir=hn5YVKscHF9oaM%253A%252CQrgO_CohKaxOyM%252C_&usg=AI4_-kQcvWbkaQc_qAqTpieviAkJQSgXLQ&sa=X&ved=2ahUKEwjomcj83oveAhXcFjQIHZs9BvQQ9QEwBXoECAUQDA#imgdii=VQRyy3YegzzT7M:&imgrc=hn5YVKscHF9oaM:)
If you're using a 240v mini split, then why do you need three separate outside units? These are designed to run multiple inside units from one compressor outside - we recently put a unit in my in-laws house (over 2500 sq ft) and ran four inside units from a single outside unit.
I'm not an a/c expert, but something doesn't sound right about the plan to put three separate outside units on one bus if you're running a 240v a/c system.
The draw back to multi zones from 1 outside unit if 1 zone is on and the others call for cool air or heat it greatly reduces the out put of the unit,they had that problem with the multi zones unit in Needles housing and needed to add another outside unit,in a bus it would probably be worse than a house
At first I was thinking about using a 240 unit and run three different zones but then reading this forum made me think twice. I don't have any other appliances using 240 and I wasn't quite sure how to power it while on the road. I only have a 3000 watt inverter 24 volt and it can't do 240. Also, someone suggested using the Costco 12k units that only use 120 and use three of them. The cost of three is still under the cost of one 240 that powers three zones. The positive of that would be redundancy. If one fails we don't loose all of our ac. So then I began to think about where to put the outside unit and I saw a pic of someone who mounted theirs on the back of their MCI bus. I hope that makes sense.
Quote from: richard5933 on October 16, 2018, 12:57:40 PM
If you're using a 240v mini split, then why do you need three separate outside units? These are designed to run multiple inside units from one compressor outside - we recently put a unit in my in-laws house (over 2500 sq ft) and ran four inside units from a single outside unit.
I'm not an a/c expert, but something doesn't sound right about the plan to put three separate outside units on one bus if you're running a 240v a/c system.
The three mini-splits might do a good job of cooling while parked, but will they be able to keep you cool while going down the road? A lot depends on whether you are well insulated, have fewer windows, and whether you are going across the West in August. Three traditional roof tops are not enough in many situations, so I have my doubts about three 12,000 btu mini-splits. If you go through all this effort and discover that they are not enough, have a supplemental plan B. ;)
So perhaps I should use a step up transformer for the front driver unit. Do you think 18 or 24k. What are your thoughts about a 12k unit in the bunk (middle of the bus) and a 12k for the bedroom?
Quote from: DoubleEagle on October 16, 2018, 07:46:43 PM
The three mini-splits might do a good job of cooling while parked, but will they be able to keep you cool while going down the road? A lot depends on whether you are well insulated, have fewer windows, and whether you are going across the West in August. Three traditional roof tops are not enough in many situations, so I have my doubts about three 12,000 btu mini-splits. If you go through all this effort and discover that they are not enough, have a supplemental plan B. ;)
What did the coach have for stock BTU in the dashboard?
That had little to do with the passenger load and everything to do with sun load on the driver...
Also, regarding exterior mounting of equipment:
You may not want to unwittingly fit the undesirable profile that "loose outside bits" puts you and coach into?
Figure out how to get everything inside the lines of the coach.
happy coaching!
buswarrior
Quote from: Jcparmley on October 18, 2018, 03:47:51 PM
So perhaps I should use a step up transformer for the front driver unit. Do you think 18 or 24k. What are your thoughts about a 12k unit in the bunk (middle of the bus) and a 12k for the bedroom?
The more the better, up front, otherwise have a paper towel dispenser close by to mop up the sweat (and fans). Entertainer coaches that go everywhere usually have big central airs or five rooftops joined together duct-work wise. 12k's in the rear areas are fine when parked, going down the road in the heat is the problem, especially up front. The cool air tends to sink to the floor and gravitate to the rear where it meets the heat generated by the engine and transmission. If you cannot afford more cooling, then it would be best to stay out of Arizona, Texas, and Death Valley in the summer. 8)
Quote from: DoubleEagle on October 18, 2018, 06:24:30 PM
...If you cannot afford more cooling, then it would be best to stay out of Arizona, Texas, and Death Valley in the summer. 8)
Why would anyone want to be in those places in the summer? That's why these things have wheels - to get to places like northern Wisconsin where we slept with the windows open in the middle of August with temps in the 60s.
Quote from: richard5933 on October 18, 2018, 06:38:22 PM
Why would anyone want to be in those places in the summer? That's why these things have wheels - to get to places like northern Wisconsin where we slept with the windows open in the middle of August with temps in the 60s.
Well, you would have ask Cliff about that. I've been to Wisconsin and Minnesota in August, and it was not always in the 60's. It was even hot at times in Canada this year.
Quote from: DoubleEagle on October 18, 2018, 06:49:50 PM
Well, you would have ask Cliff about that. I've been to Wisconsin and Minnesota in August, and it was not always in the 60's. It was even hot at times in Canada this year.
Yup, left FL end of May it was 94. Got north of Minneapolis it was 105. In fact, it was over 96 all the way there.
Quote from: eagle19952 on October 18, 2018, 08:03:30 PM
Yup, left FL end of May it was 94. Got north of Minneapolis it was 105. In fact, it was over 96 all the way there.
Do we have warm and even hot spells? Of course we do. By and large though, weather in the summer is much more pleasant in Wisconsin and Minnesota than in Texas and Death Valley. Unless one just enjoys the excessive heat.
JC -
Our "new to us" 40' Prevost has three 15,000 BTU CruisAire units, which are basically similar to the mini-splits you're considering. The coach is also spray foamed for insulation, the best you can have. Two units are in the spare tire compartment up front, the third in the second bay, passenger side.
It will not maintain 75º when it's 100º outside. Moving or parked.
The 45' Entertainer cars are using five low-profile 15,000 BTU roof units in an interior ducted format for a couple of reasons: 1) The clients stay cool in all kinds of weather, and 2) If one unit fails, the coach will still stay relatively cool and the RV dealer at the next gig can throw another unit up there in one day, compared to searching out a service center for basement or mini-split systems, thus putting the coach out of service.
I'm not fond of carbunkles on the roof either, but the newer low-profile models tend to negate that eyesore. Your genset will easily handle three 15K BTU units, especially the newer, energy-efficient Colemans, but one of the real keys is to spray foam the interior for the best insulation, thus reducing the workload on the HVAC systems. Not to mention it's a lot easier to wire in three rooftops than the mini-splits!
Buswarrior makes a good point about being extremely careful about what you "hang" off the exterior of the bus - you don't want your C3 looking like a backyard shade-tree mechanic hacked together something to make it work. RV parks and campgrounds do not tend to look at that type of workmanship favorably. OTOH, if you can integrate the HVAC into the rear roof cap similar to what today's transit buses are doing, that might be a viable solution - IF you can work around the engine radiators!
Anyway, that's my nickel's worth of suggestions, altho it's probably only 2¢ in today's economy.
FWIW & HTH. . .
;)
Quote from: RJ on October 21, 2018, 12:43:05 AM
JC -
Our "new to us" 40' Prevost has three 15,000 BTU CruisAire units, which are basically similar to the mini-splits you're considering. The coach is also spray foamed for insulation, the best you can have. Two units are in the spare tire compartment up front, the third in the second bay, passenger side.
It will not maintain 75º when it's 100º outside. Moving or parked....
Our bus has two split systems, which all signs point to having been made from commercial refrigeration units similar to those found keeping walk-in beer coolers cool. Compressor & condensing coil in the bay, evaporator & blower up above. At 100 degree with high humidity, they will drop the interior temperature from over 100 to the low 70s in just over an hour. If they ran on high all day it would be a meat locker. Each of these consumes as much as 19 amps when working full steam. It's a purely mechanical system with no electronics and just a few large relays. Original to the bus from 1974.
While you may not want to create such a system for your bus, I bring it up to remind you that sometimes it's necessary to think outside the box. Instead of sticking with something like the modern mini-split and trying to force fit them into the space on your bus, why not use off-the-shelf HVAC parts to just make a system that works best for your situation?
Do you have a relationship with a local a/c tech? This would be my suggestion - find a local guy that knows his refrigeration business inside and out. One that works on commercial refrigeration units as well and not just the cookie-cutter residential units. Buy the six pack, and have him over to brainstorm this project. Do this before you commit to something that down the road (literally and figuratively) won't do what you need. You might be surprised at some of the suggestions and what these guys can do with standard parts.
After all, an a/c system consists of only a few moving parts: compressor, condensing coil, evaporator, and blower. Add a few miles of tubing, a thermostat, some valves & relays, and you've got an a/c system.
When ours was serviced last spring the guy said that all the parts on our 44-year-old system are still available off the shelf. That's the advantage of not using a foreign made inexpensive system.
All the AC's are off the self except the newer mini splits,RJ has some top of the line AC units with his CruisAirs those 3 units cost almost 10 grand and if installed and serviced right you can make Popsicles with those.
I used 3 CruisAir for 20 years here in the AZ heat in a 40 ft Eagle never ran but 2 at the most.A residential AC or RV service can screw one up in hurry by overcharging they have a sight glass and about the only AC that requires bubbles in the Freon.
Keep the outside unit clean to prevent head pressure and have a marine CruisAir dealer service the units they were the best on the market,the fan speeds where from 0 to full none of the 2 or 3 speed crap they have a speed for everyone
My AC was designed to service Condo high rise units in Dallas,TX and retro fitted to the bus.
FirstCo is the maker. Mine is a 2.5T. unit.
https://hdsupplysolutions.com/shop/p/hvac-00-65/equipment-00-65-15/packaged-units-00-65-15-40/first-company-20-ton-thru-the-wall-condensing-unit-p259478 (https://hdsupplysolutions.com/shop/p/hvac-00-65/equipment-00-65-15/packaged-units-00-65-15-40/first-company-20-ton-thru-the-wall-condensing-unit-p259478)
(https://images.hdsupplysolutions.com/image/upload/d_no_image.gif,f_auto,fl_lossy,h_140,q_auto,w_140/259442_L.jpg)
Depth 25.5 in
Height 34.5 in
Width 19.5 in
And is slightly different dimension than this one.
With the air handler in the coach.
Been in service since the early 90's It has had the compressor replaced in 2012, is R22, and because of the way the AC regs have evolved I decided to replace the A-Coil in 2014. It is 240v. But, I'm not hesitant to run my generator, tho I don't do Death Valley in July, I have summered in Houston, Ft. Myers and Prescott, AZ.
RJ
Do you think 3 15k units will keep the bus cool? What about the driver?
Quote from: RJ on October 21, 2018, 12:43:05 AM
JC -
Our "new to us" 40' Prevost has three 15,000 BTU CruisAire units, which are basically similar to the mini-splits you're considering. The coach is also spray foamed for insulation, the best you can have. Two units are in the spare tire compartment up front, the third in the second bay, passenger side.
It will not maintain 75º when it's 100º outside. Moving or parked.
The 45' Entertainer cars are using five low-profile 15,000 BTU roof units in an interior ducted format for a couple of reasons: 1) The clients stay cool in all kinds of weather, and 2) If one unit fails, the coach will still stay relatively cool and the RV dealer at the next gig can throw another unit up there in one day, compared to searching out a service center for basement or mini-split systems, thus putting the coach out of service.
I'm not fond of carbunkles on the roof either, but the newer low-profile models tend to negate that eyesore. Your genset will easily handle three 15K BTU units, especially the newer, energy-efficient Colemans, but one of the real keys is to spray foam the interior for the best insulation, thus reducing the workload on the HVAC systems. Not to mention it's a lot easier to wire in three rooftops than the mini-splits!
Buswarrior makes a good point about being extremely careful about what you "hang" off the exterior of the bus - you don't want your C3 looking like a backyard shade-tree mechanic hacked together something to make it work. RV parks and campgrounds do not tend to look at that type of workmanship favorably. OTOH, if you can integrate the HVAC into the rear roof cap similar to what today's transit buses are doing, that might be a viable solution - IF you can work around the engine radiators!
Anyway, that's my nickel's worth of suggestions, altho it's probably only 2¢ in today's economy.
FWIW & HTH. . .
;)
RJ
Get those units serviced, inspect the physical condition of ductwork, etc
You aren't getting near 45k BTU out of 'em.
Happy coaching!
Buswarrior
Quote from: Jcparmley on October 21, 2018, 04:58:54 PM
Do you think 3 15k units will keep the bus cool? What about the driver?
JC -It all depends on where you place the forward unit. The further back, the worse it gets. A ducting kit to direct all the discharge air forward will help, too.
If you really want to keep the driver cool, find a RedDot dealer (they specialize in custom car AC units), and have them rig up a system down in the spare tire compartment and then using the existing driver's AC that your MC-9 came with. (This would be for over-the-road use, obviously.) Going this route would allow you to more evenly space the roof units.
Buswarrior -Getting them serviced is high on the priority list. Trying to find a marine service center in the Seattle area, per Clifford's suggestion.
FWIW & HTH. . .
;)
I second RJ's suggestion to power up the existing evaporator in the dashboard with aftermarket condensor and compressor.
The front end was just fine in stock configuration.
A source of cold right at the windshield can't be matched by air being blown from back in the coach.
Designing the unit to also be able to run while camping is the sweet deal.
Off the top of my head late at night... can't remember the dashboard AC BTU... it is a significant number...
Happy coaching!
Buswarrior
That's a good suggestion. Is the evaporator in the dash behind the heater core? I have a MCI 102c3. I took the front panel off to expose the heater core but I didn't see a ac evaporator. Perhaps I am missing something.
Quote from: buswarrior on October 21, 2018, 11:13:08 PM
I second RJ's suggestion to power up the existing evaporator in the dashboard with aftermarket condensor and compressor.
The front end was just fine in stock configuration.
A source of cold right at the windshield can't be matched by air being blown from back in the coach.
Designing the unit to also be able to run while camping is the sweet deal.
Off the top of my head late at night... can't remember the dashboard AC BTU... it is a significant number...
Happy coaching!
Buswarrior
Buswarrior
I will take RJ's suggestion and call Red Dot. Do you know the BTU of the OTR driver ac? I suppose Red Dot will want to know that so they can size the correct compressor and condenser.
Quote from: buswarrior on October 21, 2018, 11:13:08 PM
I second RJ's suggestion to power up the existing evaporator in the dashboard with aftermarket condensor and compressor.
The front end was just fine in stock configuration.
A source of cold right at the windshield can't be matched by air being blown from back in the coach.
Designing the unit to also be able to run while camping is the sweet deal.
Off the top of my head late at night... can't remember the dashboard AC BTU... it is a significant number...
Happy coaching!
Buswarrior