Cheap Driver's A/C for the SpaceShip

[Buffalo SpaceShip]

We picked up a clearance/ floor model portable A/C over the winter. It's a 10,000 BTU model, and we paid $150 for it from Home Depot. I plumbed the exhaust outlet for the hose into the old fresh air intake grille in the side of the bus.

Some pics and a lot more blathering about the project here on my bog:
http://www.brownland.org/blog/2007/06/11/drivers-ac-for-the-bus/

We're also going to move the unit to the bedroom when parked, so I have to find a place to dump the exhaust back there. Those snazzy angled and radiused GMC windows likely preclude me from using its window kit on one.

We're leaving later this week for a trip to the Midwest, where we'll surely get a chance to test it out. I can almost feel that cool breeze on my neck now.

I'll keep ya posted,
Brian B.

[Kwajdiver]

What a great deal,  let us know how it works OT.

Bill

[Nick Badame Refrig/ACC]

Brian,

Have lots of fun on your trip!

Don't be an "Air Hog" Lol

Nick-

[wvanative]

Brian, Maybe you could use the same type of connections that they use in the home central vacuum systems. they just snap together once you have it plumbed. that way you could plumb it just about anywhere you want. But having not seen the unit you have I'm not sure what you have to over come. Just trying to give you another idea or angel to think about.

WVaNative

[wvanative]

Well Brian, after going in and looking at your pictures I don't think my idea will work as the hoses coming out the back of your A/C unit are a lot larger than the central vac systems. I know you will figure it out though.

WVaNative

[captain ron]

Brian, Get a piece of acrylic or plexiglass and cut to fit a window opening then bore a hole for hose to fit and you will have a good looking fix for your problem. HTH Let me know how this thing works I might try to find one.

[DavidInWilmNC]

We had one of those portable 10K BTU units at work.  It cooled really well, but it only had one hose - exhaust.  It pulled in a lot of hot, humid air.  I think the two-hose models would definitely work a lot better.  A (fairly) easy exhaust idea might be down through the floor.  I'm not really familiar with GMC's, though.  There's one good thing about living in the South in summer.  Any A/C design that can keep one comfortable here will pretty much work well in most places.  This past Saturday it was 95° out with high humidity.  My singer 15K Carrier could almost keep my bus cool.  Once I was out of the direct path of the sun, the compressor started cycling.  I'll be curious to see how it does when I install the additional 8K window unit in the bedroom.  It'll be ducted up from the 3rd bay.  I'm sure I'll need another unit in the front, but that'll come later.

David

[John Z]

David, are you putting the AC unit in the bay? I want to do this eventually to mine. If you did, how did you handle the ducting? Did you remove the oem shround from the ac unit and make your own? Can you, or anyone else who has done this post a few pictures?

[skipn]

Brian,

    That looks almost exactly like the unit I have to cool down my house. It works pretty good.

  One thing to consider. The pipe/plug for the condensation trap.....I would put a hose on it to
keep it drained. On mine it started to smell I had to use bleach to get it back clean. A real
pain in the backside.

Just a thought...

  Skip

[DavidInWilmNC]

David, are you putting the AC unit in the bay? I want to do this eventually to mine. If you did, how did you handle the ducting? Did you remove the oem shround from the ac unit and make your own? Can you, or anyone else who has done this post a few pictures?

There have been a few that have used window units like this.  It's not installed yet; I've got to solder longer wires for the control panel and haven't gotten around to it.  Basically, I used a 4" X 12" duct boot and cut a hole through top of the unit (the 'room' side) so the blower blows directly into the insulated flex duct.  This duct will go up through the bus floor to a supply register near the ceiling.  I used duct board and made a panel... I'm not sure what you'd call it.  It goes around the front of the unit where the coils are.  This will also have a duct connected to it, but as it's the return, it'll be a bit bigger.  This will go up to a filter grill mounted in the bedroom wall.  I have an angled piece of duct board the width of the unit and about 5" deep that directs the hot exhaust down.  Once I've figured out where to locate the unit in the bay, it'll blow down through the floor of the bay. 

I'll have to put some sort of air intake on the bay door.  What I hope to use is a piece of the stainless mesh from a parts MC-8's condensor door.  I bought the lower piece that has the profile similar to the rub moldings around the bus.  I'll cut it about 10" long and cut out a corresponding section of the alum. rub molding.  Then, I'll have to cut a hole in the bay door for the air intake.  This way, if it doesn't work out, I just have to replace the molding to cover the hole. 

Right now, the A/C unit itself has been 'modified' but not installed.  Once I've made a bit more progress, I'll get some pics of it.  The 8K - 10K BTU window units are pretty cheap and efficient, so hopefully I'll be able to run it and the roof unit, along with other items, without any problems on 30 amp power.  As hot as it's been and will be, I'm sure I'll get this done fairly soon!

David

[Jerry Liebler]

Brian,
     You will be very disapointed in the amount of actual cooling you'll get.  The single hose portables are very ineffective in even moderate humidity because their exaust must be made up with hot humid outside air.  I had 2 in my bus and even after I ducted outside air into their condensors they were very unsatisfactory. I'll ilustrate the problem.   If the air outside is at 90 degrees and 80 % rh and the inside is at 70 degrees and 60%rh an air flow of 100 cfm from outside to inside brings in 9700 BTU/h.  Most of these portables have exaust airflows of over 150 CFM.  So to get 10,000 btu/h of 'cooling' you are bringing in almost 15,000 BTU/h.  DON"T waste your money or time trying to make portables work.  The best choice is a ductless split, next best an appropriately mounted window unit, next best is an RV basement unit,then roof warts.
Regards
Jerry 4107 1120     

[Buffalo SpaceShip]

Thanks for the advice and comments, guys.

Jerry, bear in mind that this unit will supplement my existing 15k "roof wart" unit in the center of the coach. In the driver's position, the rooftop unit is only about 10' away from this unit. So hopefully, the rooftop will handle the bulk of the dehumidification duty while we're in humid climates. I realize that it's not a perfect solution, but might provide just a little more cooling than the rooftop alone. I can also use the fan-only function to pull some cooler air off the floor behind me and put it back on my neck.

When we're not traveling, I use the unit in my upstairs office at home to supplement our central air, so it does double-duty. Here in Colorado, there's not as much issue with humidity.

Cheers,
Brian

[TomC]

Brian-like what others have said, I have had both the single hose and now the double hose at my house, and can say without a shadow of a doubt that the double hose works much better since you're not drawing in hot outside air.  I would suggest that you put another hose around the intake on the side and have that hose also feed to the outside.  Course one of the ways you can get by is to open the closest window to the unit.
Even though you live in Colorado, anytime you head east in summertime, you'll be in humidity.  Let us know how it works.  I would think that a two hose unit would be great to use the components to make your own basement air-since they are relatively cheap and many (like mine) have electric heat too.  On my two hoser at the house, the front cover comes off and it would be a relatively simple project to simply extend the controls just by adding electrical wire to it (no thermocouples).  Good Luck, TomC

[Jerry Liebler]

Brian,
       I'm curious, how well your rooftop cools your bus, do you have any data?  I also have a Buffalo and have posted several times how well my new ductless split, (rated at 18,000BTU/h) cools.  Sitting in the sun on a day when the outside temp was 92 and rh 43% the ductless split held the entire bus (I was using another fan to circulate air from front to back) at 68 rh 60%.  It did this while running 80 % of the time. 
     I'll wager you'll be cooler with the portable shut off, this will certainly be true when the outside humidity is high.
Regards
Jerry 4107 1120

[Buffalo SpaceShip]

Hey Jerry:

I don't have any real data on the rooftop effectiveness, just some passing observations... but it seems to cool the area near it OK. In humid climes, a lot of condensate pours off the roof when it's running. The rooftop is in the front lounge area, about 1/3 of the way from the front to the back. So the back area either needs another rooftop OR some other A/C style.

The problem with the driver's area of the bus it that it's almost uninsulated, because of the expanse of glass, steel cap, and front dash areas. We've found that we can cool (and heat) the bus much more effectively when we hang a heavy blanket just aft of the driver's seat at the step-up and use fans to circulate the air aft. I've considered creating a more permanent barrier of plexiglass and door, like some band buses I've seen, and using an automotive-style driver's A/C system or ductless split like yours to cool the driver. The portable A/C is just a stop-gap. We'll have to see if it helps at all... or makes matters worse, as you suspect.

We still have the coach heat and defroster and it works amazingly well during the heating season whilst underway. A single ducted RV propane furnace does OK when parked, since we don't typically use the coach in very cold weather. When we're plugged-in, we also use elec. radiant heaters.

The coach A/C is long gone, sad to say.

Thanks,
Brian