1986 BlueBird All American FE – 40 ft
First off... my thanks to Bansil for jogging our memory about building in a window air conditioner. We have built several into walls and other RV's before. I really don't know why we didn't think to use one before.
The key to building in a window unit is to allow for as much air to get to the compressor as possible. This air generally enters thru grill work on the sides and top of the air conditioner cabinet. We have learned that we need to allow at least 3 inches of space on the sides and/or top to keep from overheating the air compressor. The air for the compressor is exhausted thru the rear of the unit and this air needs to be able to exit freely. It can be quite warm. Allowing the intake air for the compressor to be pulled from a location a couple feet from the exhaust makes a big difference when you are trying to run the unit in temperatures of 100F and up.
A way to keep the “pan” drained is also needed, particularly in high humidity areas. Not all window air conditioners have a drain in their pan. The small cheap GE that we installed in the rear of the bus (bedroom area) had a hole in the pan that we had to add a piped drain. The brand new, slightly larger, air conditioner that we installed in the front of the bus did not. We had to drill a hole in one of the “low” spots before installing. Even in normally low humidity NM, the air conditioners will accumulate water in the pans. You do want to drain the water to the outside of the bus. The part of the drain inside the pans are held close to the surface of the pan like the image for Front AC 10.
I also sprayed the bottom plastic potential drip spots and the drain after it was installed with Rustoleum Leakstop (clear).
We decided to run two small units for several reasons. First and foremost, it was cheaper than buying an RV unit. I'm trying to bring the conversion in for under $4K. Second was we already had the smaller AC unit and all it was doing was sitting unused. Third, we were DYING from the triple digit heat. Well, just sweating a lot. And the heat plus lack of eating (too hot) was making us ill as well. We also want to keep this bus at 30 amps. Since we live in our bus fulltime, the cost of a monthly 30 amp site is generally significantly cheaper than a 50 amp site. Lastly, if one of the window units dies on us, it is pretty simple to stop at any Sam's Club, Wal-Mart, Home Depot or Lowes and buy a replacement to pop in the hole for under $200. Two units will also allow us to only cool the rear at night. We close off the front from the bedroom & bathroom at night. If we are traveling and staying in parking lots, this means we can run our NOISY yet-to-be-purchased generator to easily power the AC (and all the rest of the electrical stuff) and sleep comfortably.
So here's how we dun it...
Rear Air Conditioner:
We installed the Rear Air Conditioner first because it was a unit we already had. The unit is a GE 5050 Btu window unit. It has a drain in the pan. We had bought it a few years ago from Sam's Club (they had the best price) and ran it in our food cart. It does a good job of keeping the bedroom cool in the NM heat (the back wall is not insulated at this time). It could not keep the whole bus cool though. What it does do is keep roughly the back half (about the back 13 ft) at what I consider a comfortable temperature. I do not want it to be so cold that we cannot bear to go outside. So 77 F to about 81 F is okay. The rear unit is currently running off of an extension cord (albeit a very heavy one) and is plugged directly into the 15/20 amp receptacle on the campground power pole.
On our bus, the front and rear bulkheads are hollow. They normally hold wiring, flasher lights and thick insulation. After looking at Bansil's installation, David & I decided that we could use the rear bulk head as a huge plenum to channel the air for the compressor from the flasher light holes to the compressor and out thru a rectangular hole we cut in the outer wall. All these openings, we planned to cover with vent covers we bought at Home Depot. The intake air is interior wall vents that you find in the same aisle as floor/wall register vent covers. The exhaust vent is a slightly larger foundation vent.
Rear AC 01 First, the flasher lights were removed. Then we measured to find the center point (vertical & horizontal) in the bulkhead. From there we marked out the area we needed to drill out to slide the AC into the wall.
Rear AC 02 The holes are at every corner.
Rear AC 03 The holes are predrilled with a smaller bit then drilled out with a larger bit to allow the jig saw to just cut a straight line.
Rear AC 04 David used a piece of wood under the shoe of the jigsaw to keep from hitting the outer wall.
Rear AC 05 The wires we were also trying to not saw thru.
Rear AC 06 After removing the wiring that was no longer needed, I taped up the wires so they would not get in the way.
Rear AC 07 I “hit” the channel with a bit of the Rustoleum LeakStop rubberized coating (spray can). Messy stuff. I used black here. You can't see the clear stuff. This stuff really does stop leaks.
Rear AC 08 This is the rear of the old small AC unit. It has been beat a bit. The hail storm a while back didn't help either. They do sell a “fin repair” thingy at Home Depot. Looks like a metal brush and costs $14. Too much so it can stay a little messed up. This is why we will install grills over the exhaust. The clear tubing is for the drain.
Rear AC 09 The power cord (nice neat factory caulk job) and the metal plumbing strap we are using to help suspend the front of the AC unit from the ceiling. It is slid into the track the accordion filler panels used to be in.
Rear AC 10 This is a tiny plastic thing that stuck thru the bottom of the drip pan. It decided to drip., I dried it off with a paper towel and hit it with a couple shots of the Rustoleum Leak Stop. Hasn't leaked since. The larger front AC had two of these things sticking thru the bottom. I hit them with the clear LeakStop before we ever put it in. There was an opening on the bottom of the rear AC unit for the compressor. I taped it off with some really sticky exterior duct tape. The grill on the top of the unit was also covered with a piece of flashing and duct tape.
Rear AC 11 Closer view of the plastic leaky thing that no longer leaks.
Rear AC 12 This is the drain we put together for the AC unit. It already had an exiting hole. David found a bit of an air tool (threaded bushing) that fit the hole perfectly. All we had to do was find some parts that fit it. What we ended up using was a Watts A-734 Pipe Reducing Coupling ¼ inch FIP x 1/8 in FIP, Watts Hose Barb LFA-192 ¼ in ID x ¼ in MIP Brass Hose Barb Adapter, ¼ in ID x 10 ft clear plastic tubing ( from the plumbing aisle) and a neoprene washer (from the hardware aisle). The tubing runs down thru a hole in the floor. This worked well but I like how the Front AC drain turned out better. When the time comes to replace the Rear AC unit, we will use one similar to the front unit and set the drain up the same way. But still thru the floor.
Rear AC 13 The bulkhead was basically the majority of our plenum for the compressor motor, but it was only a few inches deep. So David built additional ducting to cover the remaining exposed side vents (remember, we covered the vent on the top). We had bought a roll of discontinued 8 inch x 50 ft flashing really cheap to build all the ducts and to use as needed. Here you can see how we stabilized the front with the plumbing strap attached to the ceiling. David also extended the controls (if you do the same, don't forget to extend the grounding wire). This is because this AC unit will be encased with cabinetry and we wanted the face to be flush across the rear bulkhead.
Rear AC 14 Side view.
Rear AC 15 Another view.
Rear AC 16 This is a view of the bulkhead from outside. Without the vent covers in place, it's easier to see the holes. We will be keeping the flasher shields in place. We have been thru a few nasty hail storms while in NM and we fell it will also help deflect some of the rain when we finally move back someplace that has rain. Once the vents are painted (to match the body colour), screened (to keep bugs out) and installed, it will be difficult to see that we have added a “window” air conditioner.
Front AC Unit:
The front AC unit is a 6400 Btu GE Window unit from Sam's Club. It comes with a remote. This unit is short enough that it fits in our bulkhead with room to spare. It also keeps the front (salon and galley) within the temp swing we deem favourable! We do like this unit. It did take us longer to install than we thought (over the span of two days... one afternoon til late and done by noon the next day). We also cut a piece of flashing and secured it over rear vents in the top with duct tape. The duct tape we used for this whole project was an exterior duct tape.
Front AC 01 David cutting the panel inside the front bulkhead out. Now I have to find someplace else to store my DVD movie collection.
Front AC 02 Half way gone.
Front AC 03 There were three screws holding the bottom of this metal panel in place. David drilled a few holes to get a long screwdriver in to get the screws out. Once the panel was removed, I pulled out the old insulation and extraneous wires. I also taped the needed wires out of the way.
Front AC 04 Cutting out for the AC unit case.
Front AC 05 Centered the unit the same as we did with the Rear AC Unit.
Front AC 06 David built ducts since we didn't use the bulkhead as a plenum like we did in the Rear.
Front AC 07 Cutting the holes where the old flashers used to be. They now are the intake air holes.
Front AC 08 Cleaned out and vacuumed. Now we can start putting the AC unit in.
Front AC 09 Drain line for the AC drip pan. We found a package of assorted lengths of hollow 1/8 in -IP threaded nipples in electrical along with two packages of nuts and washers to fit the threaded nipples. They are used for making/repairing lamps. Normally electrical wire runs thru it but we think it works just fine for a drain. We used a plastic tube with 1/8 in inside diameter. We drilled out one of the rivets above the windshield under the front side marker.
Front AC 10 We put a bit of Henry's elastometric roof caulk on the threads to make a waterproof seal and to keep the nuts from loosening. What putting the drain here does is run the water down onto the gutter above the windshield and it runs off on the driver's side of the bus.
Front AC 11 We had to cut a notch under the AC unit so that we could get the screwdriver in to tighten the hose clamp on the drain attached to the AC pan.
Front AC 12 Plenum from the flasher light holes.
Front AC 13 Duct taping the openings around the AC unit to prevent hot exterior air from entering our soon to be much cooler home. We did this with the Rear AC Unit as well.
Front AC 14 Plumbing Hanger Strap to help hold the unit in position until we get everything finished up. The strap will be left in place.
Front AC 15 I have to cover /seal off the passive vent in the ceiling above the AC unit. I do believe part of our cool air is escaping thru it. I just haven't climbed up there to fix it yet.
Front AC 16 Forming the remaining part of the plenum.
Front AC 17 Buttoning it all up.
Front AC 18 Ductwork is complete.
Front AC 19 Time to turn it on!
Front AC 20 Exterior view before vents are painted and installed.
Front AC 21 Front AC Vent Covers
This is the Front AC with all the vent covers in place before I painted them. When I paint the covers, I will pick out the "star" on the exhaust covers and paint it as a compass rose.
Front AC 22 Close up of Exhaust cover.The vent cover does not protrude much. Once painted we think the vents will blend into the body of the bus pretty well.
Front AC 23 Head on View We felt that we needed something to protect the front AC while traveling down the road as well as to keep the strong NM winds from blowing backwards against the compressor fan. We have found that it was causing problems with the Rear AC unit.
Front AC 24 Frontside of the Foundation Vent For the intake air, we used foundation vents from Home Depot (14 in. x 6 in. Model # FV146G Store SKU # 105571) for $4.76 each. They are a little sturdier than the interior wall vents that I had originally bought (and returned).
Front AC 25 Backside of the Foundation vent. They are also screened to keep the bugs out David used offset metal cutting shears to trim the top corners so that they would fit inside the flasher shields. I wanted to keep the flasher shields as they would also provide protection from rain and hail.
Front AC 26 Frontside of the Exhaust Cover I bought two roof vents (no fan) at Home Depot (Model # RVG51M Store SKU # 336271) for $8.66 ea. These vents are made to slip under asphalt roofing shingles. That means the top edge (it says "UP" on them) is slightly longer than the other sides. Since we turned the vents on their sides, that means they are ever so slightly off center. I don't think it's all that noticeable.
Front AC 27 Backside of Exhaust Cover This photo shows the screen that is attached (lightly tacked) in place. Before installing the covers on the front AC, we used Great Foam - Big Cracks & Gaps canned foam to spray around the opened areas to keep rain from puddling up inside the front bulkhead. Butyl tape was used to seal the vents to the body of the bus.
Remaining work to be done (this post will be updated as completed)... The identification plaques on the front bulkhead (interior) need to be removed to another location before the bulkhead is insulated and covered with a sheet of plywood. The radio needs to be reinstalled (round opening to the left of the AC unit). The rear bulkhead needs to be insulated (it gets pretty warm when it's in high 90's & up) and closets/cabinetry needs to be built/installed. Rear wall/headboard needs to be built/installed. We want to do something with the front bulkhead storage wise. Haven't figured out just what yet.
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