How to - Window A/C in Dolphin

[waiter]

I traded the small Cabinet over the Frig for a small 5000 btu window unit A/C unit.

I chose a 5000 btu unit because I can run it on a small 1000 watt generator. The 5000 btu should be able to keep the inside cool, even on the hottest days. If a 13000 btu will cool a 30 ft trailer with slide outs, 5000 btu should cool the 14 ft of living space in the Toyhouse without slide outs.

I choose this particular model (Frigidaire model # FRA052XT7) because of its physical size. The depth of this unit fits perfectly in the old cabinet space.

Check out the Frigidaire website for more specs Click here for A/C Specs

I wanted to use a Window unit, but I didn't want the unit hanging out like window units need to be. I saw a window unit installed in a new RV Trailer at one of the shows and it was completely enclosed. They accomplished this by building the A/C unit into a plenum that pulls outside air in through a roof vent.

Hey we already have a roof vent, AND a lower vent that services the frig. I can use this plenum for cooling air for my A/C unit.

I removed the cabinet doors, and used a sawzall to cut the center post out of the a cabinet. I then used a razor knife to cut through the back wall of the cabinet and into the Frig Plenum. I had to use the sawzall again to cut a cross support out of the cabinet back wall.

I ordered a Dometic exterior door on e-bay ($30), I centered the new door above the original lower door, and about 4 inches below the roof. I marked the opening needed and then cut the outer wall with a sawzall.

Test fit the door frame in the hole for a good fit. The door fame has holes in it for mounting. I cut two pieces of metal angle , one for the top and one for the bottom. Using #8 bolts that were 2 inches long, through the door frame, outer wall, and through the angle metal. The metal angles back the frame on the inside and also will help support the A/C unit. Before setting the door frame, run a bead of caulk on the inside of the door frame to seal it. After the frame is set in place, clean up the bead and add more caulk as needed.

Building the A/C mount frame. I used 1/4 x 20 bolts for the frame structure.

I bolted a piece of angle to the bottom support of the cabinet using 1/4 x 20 counter sunk bolt heads so the heads wouldn't stick out.

The two angles that the A/C rest on mount between the bottom inside support, and the angle that was mounted on the bottom inside of the Dometic Frame

Looking from the inside out, the back support (the bottom metal angle on the Dometic Frame) was about an inch lower then I need, So I bolted two angles together, then bolted this to the angle at the bottom of the Dometic door. The height was now perfect. Test fit the A/C, it should tilt back just a tine bit when the truck is level.

Slide the A/C unit into place so the front sticks out past the cabinet about 1 inch or so. I cut a piece of metal angle about 22 inches for the top front of the A/C unit to clamp the A/C unit in place. Cut two threaded rods about 14 inches that run through the bottom angle and then tighten them at the top to clamp the A/C unit so it wont bounce around

I bought a small piece of Oak paneling and cut it to fit the entire opening of the cabinet. (about 23x18) I then cut the opening for the A/C to stick through (about 16x13). I ran self adhesive foam all the way around the front of the A/C unit so it would press up against the Oak cover and seal those minor imperfections between the oak cover and the A/C front panel

Condensate Drain

Most A/C units will either drip condensate water out the back or use the fan to sling it into the condenser coil. Regardless, you need to supply a drain to make sure water is not allowed to just run out of the A/C (you don't care when its hanging out a window, but you don't want water draining inside the Toyhouse.

I drilled a small hole in the bottom of the A/C unit and screwed in a 3/8 tube barb pipe fitting. I JB welded it inside and out. When the JB Weld cured, I used a Dremel tool to cut/grind the inside down as low as I could get it. The inside of the drain sticks up about 1/8 inch above the bottom of the A/C. Condensate sitting in the bottom of the A/C swill drain out this tube

When I installed the A/C, I ran the 3/8 tube down the side, and drilled holes in the bottom of the Frig to run the tub through (NOTE - I had to climb under the MH and drill the bottom hole from the under the truck) The condensate drain tube goes through all the way through and exits out the bottom of the truck behind the rear wheel. (You can see the black tube on the right side of the Frig opening)

110 Power

I ran the A/C power down beside the condensate drain tube and plug it into the same outlet as the Frig is plugged into. The Frig came with a GFCI plug. I had to cut that plug off and install a standard 3 prong plug (The GCFI plug wouldn't fit in the small space)

INITIAL TEST

This unit is very quite, both inside and out.

Running the A/C with the external upper door closed, I could feel the hot air blowing through the upper door, The door was warm and seemed to have good airflow. I need to install a small deflector on each side of the A/C to plug the gaps and keep exhaust from leaking back in to the plenum. You can see the gaps in the photo that shows the back of the A/C unit.

One option - If I'm parked and its hot outside, I can prop the upper door open to get better air flow through the A/C.

The next hot day we get (90-95deg) I'll run the A/C and see how it does.

REFRIGERATOR EFFECTS

I need to run the frig and see what effects the A/C unit has, both running and not running. The A/C unit is reducing chimney air flow. I think I'm OK, but test results will verify. I'll post this later. ( I turned the frig on and put water in the ice cube trays, I'll see if I can still make ice cubes.)

EDIT 21 Sep 2011

WARNING - DO NOT run the Refrigerator on propane when this A/C unit is running. There is a risk that the A/C unit could draw in Carbon Monoxide. Switch the Refrigerator to 110 volts any time you want to run the A/C unit.

STAY COOL

John Mc

88 Dolphin 4 Auto

[WME]

Instead of side baffles, try using the 1x1 foam used for install room A/C in houses. Just glue it around the back of the A/C. That way the A/C will seal against the vent door and wont be able to recirculate any air back to the A/C condenser inlets.

The install looks very neat overall. Unfortunately there are some of us whose refer is side vented and not roof vented

[waiter]

I thought of doing that, but that would reduce the exit area on the Dometic door to the same footprint as the back of the A/C. by closing off that 3inch wide x 14 inch tall gap on the sides of the A/C, I still have full use of the Dometic door for exit air.

I'll post a picture when I get the two covers installed (maybe tonight)

John Mc

88 Dolphin 4 Auto

[WME]

Well in that case, don't forget to duct tape over all the holes in the Dexion brackets. If you build any pressure in the exhaust area because of the difference inlet and outlet areas between the A/C and the grill it will bleed back through the holes.

[waiter]

I was going to cut a strip of sheet metal and RTV it over the angle iron holes. Try and get as much of the hot air to exit out the Dometic cover as I can. It looks pretty good so far, but its been cool, so no need to run it.

Also, It looks like the frig is breathing OK. Its getting cold inside and it has frozen water bottles I put in the freezer,

John Mc

88 Dolphin 4 Auto

[el dave]

Nice, creative job. Could you just add another vent for the fridge above the access door? Lot's of RV fridges vent out the side instead of the roof.

Dave

'91 Winnebago Warrior

[waiter]

My original plan was to cut a hole in the roof for the intake air - This is how it is done with the RVs that I've see that used a window unit. They use a standard frig roof vent cover to draw air into the unit, then they exhaust it out the side similiar to how I did it.

I think the newer Winnnis use a side vent for the frig. It might be possible to cut hole in the roof and install a standard roof vent, then do it similiar to mine.

JOhn Mc

88 Dolphin 4 Auto

[Dolphinite no longer here]

John,

Very nice! I'm going to do the same thing!

John

[Dolphinite no longer here]

John,

I was given a small window AC today and am planning on installing it in my Dolphin. I have a question about the condensate drain. There isn't one on this unit. It's a 5,000 BTU unit made by Haier. Why no drain?

John

[noahrexion]

Dolphinite - what floor plan do you have? Please document, as nice as watier does if possible, your project!

Oh and your condensate - since its a window unit and designed to "hang out" - may very well not have a hose/line but instead either 1) accumulate and flow off of the corner of the behind-end or 2) not have one at all and have self evaporating technology (as many new ones do)

[5Toyota]

Dolphinite Haier that is the same unit i am using they must be tipped back and down to drain out back otherwise they can start dumping water out the front have had one instance of that we mount ours in front window of the cab take out when going on the road they need to set i a house window same in a house some people drill and build a drain my son has a big 240 volt unit at home drilled holes in bottom but be very careful you drill the colling system and it is junk those are a low cost unit i paid just over 100 dollers for mine

[waiter]

The A/C I used for this project was on sale a few weeks ago, $99 at Sears or K-Mart (normally $139)

GETTING RID OF WATER

A lot of the new units use a "Sling" method to get rid of the water. The water drains off the evaporator, pools around the condenser blower, the blower picks it up and throws it into the condenser coil. This increases the efficiency of the unit by a couple percent, i.e., throw the cold water on the hot condensor to help cool it down.

DO NOT RELY ON THIS - If for some reason (very humid) you get more condensate then the slinger can get rid of, water will either overflow and drain out a hole specifically designed for this OR it will dump out the back of the unit. Regardless, you don't want to dump water in your frig compartment, so you must provide a positive way to drain condensate.

Your going to need to take the cover off the unit and figure out a place to drill a hole in the bottom for your drain.

CONDENSATE DRAIN

You must supply a sure way to drain condensate, I had thought of making a pan that the A/C would sit in, but ultimately decided to just install a drain in the bottom of the A/C.

Regardless of what unit you decide to use, you must drill a hole at the low point in the bottom and install a drain. If you not sure, take the cover off and dump a glass of water in the bottom and see where it goes.

I drilled a large hole in the bottom that I could screw a 1/4 pipe fitting into. I bought a plastic 3/8 tube 90 deg barb fitting, with 1/4 inch pipe thread. I screwed this into the hole, then used JB weld on both inside and out to get a good seal and also secure the fitting to the bottom of the A/C unit. The barb points toward the side of the unit, make sure its pointing in the right direction so the drain hose doesn't need to do any sharp bends when you install it.

After the JB cured, I used a Dremel tool to grind down the inside as for as I could. It sticks above the bottom about 1/8 inch. The max depth of water on the floor of the A/C unit should now be just a little over 1/8 inch, then it drains out the drain tube.

DRAIN TUBE

I routed a 3/8 tube down the side of the frig compartment, through the floor of the frig compartment, and it sticks out the bottom of the truck about 3 inches.

To run the tube , The Refrigerator doesn't sit on the floor of the MH, it sites on top of a 6 inch hollow compartment, so when drilling the holes to run the tube in, I had to drill two holes, one from the top, but then had to crawl under the truck and drill another from the bottom ( getting them to line up closely).

The A/C unit should tilt back a tiny bit, the goal is to get any water to flow back toward the drain that I installed. If it tilts back to much, water could spill over the back edge before it can goes down the drain. With my particular A/C unit, it doesn't need to be tilted back at all, The way the bottom pan was designed, water will flow back and away from the evaporator, I tilted it back any way. The back is about 1/2 inch lower than the front when the truck is level.

JOhn Mc

88 Dolphin 4 Auto

[waiter]

I have a couple more photos of the A/C unit, but this one should be OK.

I removed the cover from the A/C, and drilled a hole in the bottom of the unit. In this photo, I screwed the barb fitting into the hole, then ran some JB Weld around the inside, AND the outside to secure the fitting and seal any leaks.

After the cure, I used a small Dremel grinding tool to grind the fitting down so it stuck up about 1/8 inch above the floor of the A/C unit (The photo shows before I ground it down)

NOTE - When your driving down the road, any water that's sitting in the bottom of the A/C will slosh around. and ultimately find its way to the drain.

WINTER STORAGE - When I'm going around draining and flushing the hot and cold water lines for the winter, I'll run the A/C in FAN ONLY to help evaporate any water that may be sitting in the bottom of the A/C unit so it won't freeze. ( I can do this when I'm traveling down the road, just plug the unit into my inverter and turn it on)

JOhn Mc

88 Dolphin 4 Auto

[Dolphinite no longer here]

John,

Since I'm air conditioner challenged, I have another question or two. My refrigerator vents out the side of my '85 Dolphin so there's no roof vent. The AC unit I got vents the hot air out the back like yours. Also, there are two vents on the side of the unit, one on each side. Are these vents used by the air conditioner to draw in air to be cooled? Do they need fresh, outside air or can they draw air from the cabinet the AC unit will be mounted in? If the AC unit needs outside air, I should be able to construct two sheet metal plenums, attach them to each side of the unit and run them through a new roof unit, right? I know, sounds like a lot of work, but then I've got a good shop, lots of time and very little money...

John

[acudoc]

I am doing the same installation.

If you plug your air con in and put some paper near the sides, rear etc you will see the suction or blowing from each.

Henry

John,

Since I'm air conditioner challenged, I have another question or two. My refrigerator vents out the side of my '85 Dolphin so there's no roof vent. The AC unit I got vents the hot air out the back like yours. Also, there are two vents on the side of the unit, one on each side. Are these vents used by the air conditioner to draw in air to be cooled? Do they need fresh, outside air or can they draw air from the cabinet the AC unit will be mounted in? If the AC unit needs outside air, I should be able to construct two sheet metal plenums, attach them to each side of the unit and run them through a new roof unit, right? I know, sounds like a lot of work, but then I've got a good shop, lots of time and very little money...

John

[Dolphinite no longer here]

Acudoc-

I did the paper thing and the side vents do suck air in to the AC unit. My question is will the two vents get adequate air from inside the cabinet I'm going to mount the unit in or do those inlet vents need outside air?

John

[waiter]

The A/C unit needs to draw air from the outside. In my installation, the A/C pulls air in through the Frig lower door AND the roof vent.

If your frig doesn't have a roof vent but uses an upper side vent, and your going to use the upper vent it to exhaust your A/C air, then you need to find another way for the frig to breath, i.e. cut a hole in the roof for a roof vent. (maybe - keep reading)

The frig MUST have free air flow from bottom to top.

OK - The rest of this reply regards air flow for the frig when there isn't a roof vent, AND, When the A/C unit isn't running. Possible Might work???

((ED NOTE - See post #36 - There seems to be adequate airflow thru the A/C unit, even when its not running to allow the frig to work. This is an Infrared photo of my installation with the roof vent blocked. In this case, the hot air from the frig flows thru the A/C unit. Although this path does restrict the Frig airflow, it seems acceptable and the frig cools OK..))

Not sure if this is what your thinking?? Air comes in the bottom vent cover, flows up past the Frig coils, continues up and enters the side intakes of the A/C unit, it then flows through the condenser and out the back of the A/C , through the top vent cover and out to the world.??? This would be the convective (hot air rises) path. The only difference between what you have now and what your proposing is, the frig air would need to flow through the A/C unit to get to the outside .

Conceivably, this should work, although there are lot of restrictions to the free air flow, I haven't tried this, so not sure it would work.

Obviously this would work fine when the A/C is running, as air would be drawn in from the bottom frig vent door and up past the frig.

I can try this on mine - I can plug up the roof vent and see if the frig still works, i.e. with the A/C off, can enough air flow through the A/C unit (via convection) to give the frig enough air to work???

On my installation, I still need to block air leaks for A/C exhaust air. right now air blows out the back, but some of the air can sneak around and and come back in on the sides. I'll get these installed this weekend and then cover the roof vent and see if the frig can still breath ok.

We might be on to something....

NOTE - You got me thinking, I seen those small frig top vents with three slotted openings, not very much compare to the openings in my door vent, I'll bet if you replaced the slotted openings with the door that I have, that would provide more sq inches of opening area, and help make up for the fact that the A/C would be restricting the Frig air flow.

Are you following me on this??? I'm starting to think this would work.

JOhn Mc
88 Dolphin 4 Auto

[Dolphinite no longer here]

I plan on installing an outside louvered door for the AC unit's exhaust air like you did. I also plan on sealing it fairly well so that the AC unit doesn't pull in any of the hot exhaust air.

My Toyhome's interior layout is different than yours. I have the rear dinette model with the frig to the left, just inside the entry door. I plan on removing a portion of the overhead cabinet and building a slightly larger one that will extend down past the remaining cabinet. I thought that I could then install two vents for the intake air on either side of this new cabinet. They would be just about opposite the intake vents on the AC unit. This, of course, means that the AC unit would be drawing in air from inside the motorhome. Will the unit work okay like this?

The frig should still work as it originally did since both of its louvered doors will be below the new AC door.

By the way, thanks for your help and comments on this project. The whole idea makes a lot more sense than having a heavy, less efficient unit up on the roof. I figure that if the outside temperature is in the mid to high nineties and the RV inside temp is in the mid seventies (which I think this unit is capable of) all the effort will be worth it. Not to mention the fact that the power needed is less than half that of a 13,500 btu unit, saving lots of hard earned $$$$$.

John

[waiter]

I wouldn't use inside air for the Condenser, If you do, you'll be drawing in outside (hot) air from somewhere (air leaks). Your A/C will be fighting itself, i.e. cooling the air that its using to cool itself.

You paid good money to cool that air, don't heat it up then dump it overboard.

ALSO - It takes over 500 times more cooling capacity to remove water from the air, than it does to simply cool the air. This is why you should always operate an Air conditioner in recirculate mode, the water has already been removed, now your simply cooling the air. If your constantly drawing in outside air, you using that cooling capacity to remove water, not cool the air. In other words, do NOT use cabin air as the source for your condenser.

If I understand correctly, you have a cabinet above the frig. If I was standing in front of this cabinet with the door open and looking inside, does this cabinet go all the way to the outside wall. (take a couple photos) If so, you might be in business.

From the outside, remove the top frig vent cover and look up, I bet you'll see the floor of that cabinet. if so, just cut the floor out and you now have an air supply for the A/C.

JOhn Mc

88 Dolphin 4 Auto

[waiter]

I finished up the installation today when I installed the two side covers to seal off the exit air. I found some metal trim ("L" shape") that I had left over from building my pole barn. Cut it to fit perfect, I then slid in some foam between the trim pieces and the back of the A/C unit.

Testing the unit I got good airflow out the exit. Although the A/C works with the exhaust air door closed, I believe when I'm parked and need to run the A/C, I'll just unlatch the door and prop it open a few inches to improve air flow.

I also included a couple photos of the A/C unit front before the cover is installed. This is how I clamp the unit to keep it from sliding around.

John Mc

88 Dolphin 4 Auto

[acudoc]

Hi John I finished my install. A little differant then yours.

I had dif. dimensions etc for the plenum.

Posted on the yahoo site.

Will be adding a vent fan below to make up for the blocking of the plenum.

[waiter]

Looks good - Where did you find the exterior cover??

ALSO - I'm betting you won't need the fan, as long as there is a reasonable opening that the frig air can get through. Try it before you go to the trouble.

JOhn Mc

88 Dolphin 4 Auto

[acudoc]

I got it at home depot it. Is really two pieces. I posted a picture of it on the yahh site.

I already ordered the fan.

Henry

Looks good - Where did you find the exterior cover??

ALSO - I'm betting you won't need the fan, as long as there is a reasonable opening that the frig air can get through. Try it before you go to ti

JOhn Mc

88 Dolphin 4 Auto

[dbl047]

Hey guys I am new to the forum, this is my first RV... I had a tent trailer prior to this.

Wow... this is great! I will have to do this before next spring hits. Thanks for the write up. I was actually going to look at a roof mount, but this idea is much much better.

[90toydolphin]

just got a 90 dolphin. love the air conditioner install. seems i have the same frig cabinet config as you, just up front of the entrance door. question. when you cut into the outside did you have to cut any of the main framing of the coach? you mentioned pictures on yahoo? just learning how to navigate around this web site.

randy

[waiter]

Where I cut mine, there is no framing. just the outside fiberglass, Styrofoam, and the inside plywood.

The plywood can be cut with a razor knife.

John Mc

88 Dolphin 4 Auto

[Dolphinite no longer here]

John Mc,

Have you tried your AC in hot weather yet? If so, what kind of temperature drop do you get with 5,000 btus?

John J.

[waiter]

It was 95 deg last week and very humid

I had the curtains and blinds closed and the AC was able to get it down to between 75 and 80, Most defiantly cooler than outside, and it was pulling a lot of water out of the air.

I also discovered a water leak and had to make a plug for the bottom of the AC unit. JB Welded a small washer in the hole and the condensate now drains out the hose.

I have an infrared camera at work, next hot day I want to plug the roof vent and see how well the frig breathes through the AC unit.

JOhn Mc

88 Dolphin 4 Auto

[90toydolphin]

waiter, when say fiberglass do you mean a rigid thick material or thin sheets similar to aluminum which is flexible? mine is thin and flexible. i'm concerned that when i try to cut the thin material it'll crack creating a mess.

[waiter]

Its not real thick, use a metal blade in the saw.

I used a Sawzall with metal blade, cut through it like butter.

Don't cut anything until you have the door in hand.

JOhn Mc

88 Dolphin 4 Auto

[90toydolphin]

i'll get the door first. again on the siding, is your fiberglass rigid or flexible?

[waiter]

The outer skin is probably 1/16 thick, It could probably be cut with a razor knife.

JOhn Mc

88 Dolphin 4 Auto

[90toydolphin]

thanks. now i'm confident that mine has basically the same siding. after reading problems caused by roof units i'm more convinced that doing the one above the frig is the way to go. thanks for all the pics and info on putting it in, will be looking it over very closely as i go.

[acudoc]

Just got back from a week in mammoth lakes.

On my install I cut the hole etc with a sabre saw. The outside wall on a Winnie is about one and a half thick.

No supports etc to go through.

I posted pictures on the yahoo site. Henry's 92 Winnie.

The ride. Worked great this past week but it was cool outside.

I saw some super quiet large computer fans at fry's to increase the draft maybe a good option.

I have a Yakima box on one side of the roof. Amazing how much cooler to the touch the ceiling is under it.

Makes me wonder a out trying some of the 'insulating, paint.

Henry

thanks. now i'm confident that mine has basically the same siding. after reading problems caused by roof units i'm more convinced that doing the one above the frig is the way to go. thanks for all the pics and info on putting it in, will be looking it over very closely as i go.

[acudoc]

I was talking about the fridge not the ride:-)