Roof air or mini split??

[luvrbus]

i only meant that a bus needs to be as efficient as possible.
regardless the amount of insulation.
where does redneck play into this discussion ?

Yep a bad choice of words most bus owner do have a little red neck when it come to modifying any part of a bus 

[Jim Blackwood]

I like the idea of re-purposing the existing condenser and evaporators. Now here is another thought to consider:

Heat pumps use a shuttle valve for the purpose of allowing full flow in one direction and an orifice for reverse flow. Actually I think they must have two of those, one in each line on either side of the "A" coil but not being a full fledged A/C tech that's just a guess. There's more to it obviously. Anyway, why not just run two compressors in parallel? One on the engine and another electric unit run from the shore line? Might need a check valve or two in there somewhere to keep from bleeding pressure back through the pump that wasn't being used (or not) but it seems like this could work.

Mismatched component sizes... yes that would have to be dealt with. The shoreline compressor is not going to be anywhere near the size of the engine driven pump. Just filling the liquid line would take a bit of time and the expansion valve would have to be able to close down to a veritable trickle somehow. Not sure how to do that but there must be a way.

Sounds kinda complicated but if enough redneck minds attacked the problems I'm sure it could be done.

If it was figured out you still have a big system with lots of refrigerant but maybe you could spec a cheaper, more available refrigerant.

Jim

[Iceni John]

We don't bother with a/c, yet. But I did have an idea at one point to install a house window unit by cutting a hole in the side of the bus under a window. Then I was thinking you could either use a fridge side vent or make a nicer door like many RVs use for their storage bays. It would be pulled into the bus when you moved. For those of us who don't move all the time it would be an option. The major advantage is cheaper and window units pump quite a bit of cold air.

But, there's many reasons we never did this. I don't think we will. It's ugly. maybe if we park the bus on our own land permanently someday...

If it gets too hot to be somewhere we move on. Someday that'll change and we'll probably go with the split units.

That's basically what I'll do for my bedroom.   A small 5K window A/C will fit into the rear roof cap above the bed, and the front of it will be have a door just like the overhead storage cabinets on either side of it, so there's nothing to see when it's not working.   And it should run for several hours off my house batteries if it's a stinkin' hot night, assuming I haven't driven to somewhere cooler instead (isn't that why buses have wheels?).   Yeah, they're noisy, but that's what earplugs are for.

And for the rest of the bus, a 12K inverter mini-split with heat pump running off solar  -  yes, it can be done!   

John

[eagle19952]

Yep a bad choice of words most bus owner do have a little red neck when it come to modifying any part of a bus 

LOL..We called it something else..I think the politically correct name now is African.

[jraynor]

Has anyone used an office type a/c unit before. I have someone local who is sell some and he is asking $1500 each ($1300 each if I buy 2) and they are 1.5 Ton (17,300 BTU to be exact). These can easily be ducted as they blow from a vent on the top (I think they actually sell a type of adapter)

What does everyone think?:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=2ahUKEwjB6Y-mrszcAhUl0YMKHTAnD0kQFjABegQIAxAC&url=https%3A%2F%2Fwww.portableac.com%2Fwp-content%2Fuploads%2FSpec-Sheet-1.5-Ton-Spot-Cooler-TZ-18A-18B-HA1.pdf&usg=AOvVaw3WMKiRHVSLr7KHY2h5lw1-

According to Amazon, they are $4K each new. I imagine that the control wires could be extended into the bus pretty easily.

Would these be better over the $900 Costco MrCool Split units?

Thank you

[Lee Bradley]

they work well. I have seen them in a number of stores and cafes that don't have central air but for a bus can you give up the floor space?

[eagle19952]

Has anyone used an office type a/c unit before. I have someone local who is sell some and he is asking $1500 each ($1300 each if I buy 2) and they are 1.5 Ton (17,300 BTU to be exact).
Would these be better over the $900 Costco MrCool Split units?

Thank you

I bought one of these for my mother to use while the central air is being replaced. At $500.00 i would consider two of these before $2600.00 worth of those.
it makes the kitchen/den area (800sq/ft and open to the rest of the house..there are no doors to close the area off) easily tolerable in Alabama 98 degree days with 110 degree index and unbearable humidity. She is 98.
Yes, i was skeptical.
I would buy another.
https://www.lowes.com/pd/Hisense-500-sq-ft-115-Volt-Portable-Air-Conditioner/1000338609

PS there is/was a smaller unit in the bedroom
PSS...condensate tank is not a factor with the Hisence.

[jraynor]

they work well. I have seen them in a number of stores and cafes that don't have central air but for a bus can you give up the floor space?

Ideally, since they are ducted, they would go in the basement and come up through a wall or even duct into the original ducting for the front. For the back, I would place it in the engine bay with its own box (to keep it from drawing air from the engine bay) and duct it up behind the back wall.

eagle19952,

I actually have one of these for my house that I use rarely. I want to have a central system type setup for the bus. The only downside to the unit I posted and the one you posted is that they don't have a heat pump like the split systems do. Right now im still leaning towards 2 12k BTU split systems

[luvrbus]

Mini splits are struggling here today @118 and asphalt temp @ 145 I had to move my bus out of the shop so a friend could move in, he couldn't find enough of a shady spot in the RV park to make his work and it is friggn hot with humidity   

[brmax]

Makes a person like me in the midwest wonder?

What are the central air units in the southwest peforming like.

They must be as here typically mounted on a concrete pad.

The topic sure keeps me considering options.


Good day

Floyd

[luvrbus]

My outside unit does ok setting on the pad in the shade and drawing air from 3 sides ,his mini splits just have 1 intake, we have cold front today a high of only 109

[Oonrahnjay]

...  we have cold front today a high of only 109

      It's OK, it's a dry heat.