need Advice On Installing A/C In Teardrop

[sandman]

Hey Guys,

My build is progressing nicely and I just decided to put A/C in my Teardrop. I bought a Haier 5200 BTU Window A/C from Walmart a few days ago for $104 on sale. I have decided to put the a/c on the front of my tear right where my head will lay in the Teardrop.



Above is an image of the exact unit I just purchased.

Can you guys tell me what if any special construction techniques I need to do to install the A/C. The dimensions on the A/C are 12.0 L x 17.28 W x 11.15 H and the weight is 45 pounds. When I begin framing my spars, do I simply frame out an area the same size as the A/C?? Any help on this is much appreciated. I have no clue what to do.

[Alphacarina]

I'm putting A/C in mine too, but it's going to be completely built in and in the back, so it's not right by my head

John has the best 'solution' for completely hiding it from the outside that I've ran across - Check out his photos http://www.mikenchell.com/forums/album_personal.php?user_id=336&sort_method=pic_time&sort_order=DESC&start=12

I'm building a small 'cage' at the front, on the tongue which will hold a little Honda EU2000i to run the A/C and the spare tire will be just in front of that, so no room at the front for the A/C too

Don

[Dave Bob]

Woodbutcher has an interesting install here
He has the same type or style unit.

Dave

[asianflava]

That must be the updated version of the unit I have. I just have a knob for the thermostat instead of a digital one. Mine is totally enclosed in the trailer. It vents exhaust out the top and sucks in it from the galley. The unit sits in a pan of sorts with drains in each back corner.

I've used it for several 90+ degree days with no problems. I too don't want the a/c blowing directly on me so I mounted it up high. I can use the fantastic fan for times when there is no shore power.

[Woody]

The main concern is to remember to allow rear unit cooling air (side vents) and the hot exhuast air from the back of the unit not to mix. Allowing the side vents a separate cool air source is essential for operation. While directing the hot exhuast air out and away from the cool air supply is required to keep the unit operating normally. An increase in operating tempeture in the hot exhuast increases compressor head temps and pressure which makes the unit thermally shut down from overheating. The other thing to consider is that the units are designed for low restriction air flow so to restrict the exhuast air flow will cause the unit to overheat also. The fan that cools the back of the unit is design to push the air through and they are not strong enough to over come small exhuast openings Plus they are designed to operate with some condensate water in the pan. You will have to ensure that the unit can drain freely to prevent water slinging and water damage. Always tilt them back in your design to allow water flow so it can drain. Most people don't consider this and go camping and not allow for the unit to drain when they level a trailer. It is better to consider this during your build that have the unit flood your cabin and matteress during the night just because it wasn't level so it could drain outsde the trailer. Just my two cents worth. Good luck with your build

[Roly Nelson]

My AC unit is within my tongue box. I cut a hole through the box and the front of the tear and it matches the supply and return of the unit. I built a wooden scoop in front of the supply opening and it directs the cool air up and along the ceiling, not across my nose on the pillow.

The tongue box is firmly attached to the front of the tear and the connection is waterproof.The compressor heat is vented through a grille in the front of the tongue box. It works great, would probably freeze ice on the windows if it ran too long. I travel with the AC unit in the car, then slide it in place when I get to the camp site. That way, it lessens the tongue weight enroute.

Roly

[asianflava]

I agree with Woody, it is important not to let the exhaust air mix with the intake. This and drainage are the most important hurdles when deciding where to place your a/c unit. Here are some more pics of how I installed mine.

This is the "pan" that my a/c unit sits in. The hose is just to make sure as much water as possible makes it to the drain.


Here is the ramp that exhausts the hot air out. The intake comes in from behind the ramp and travels around the sides of the ramp. The vent was not yet installed in this pic, but it goes on the rear bulkhead wall.


This last shot shows the insulated wall that forms the inside wall of the upper storage compartment. They are removable so that I can remove or service the a/c unit if needed.


If I were to do it again, I'd raise the unit up a little higher so that I can get taller sides on the pan. Also I'd drill a hole in the bottom of the a/c unit to allow water to drain out. The bottom of the a/c unit forms a pan and has a drain in the rear (where I installed the drain hose). The water level must reach a certain level in order to drain out, there is a slight lip where the hose barb mounts.

A slight bit of water always stays in the unit's pan. When you go to move the trailer, it sloshes onto the bed. It's not much but it's kind of annoying.

[mikeschn]

You could always install it on a slide...

[GPW]

Wow!! That's a Super Idea , especially with the shade/rock protector...!!! ... mind if I borrow that ??? That'll work perfect on the Airliner...

[mikeschn]

Go for it!

Mike...

[dhazard]

More pic's in my album.

[Woody]

I had forgot to mention that a window shaker units also has trouble dehumidifing the cabin air. It has alot to do with cooling the small volume of air contained in a teardrop with the overkill of BTU cooling power. This causes the A/C to short cycle and only cool the air but not long enough to dehumidify it. Leaving the cabin cool yet damp. The trick is to fool the units thermostat into thinking it has to cool a larger volume of space, effectively allowing the cabin air to dehumidify also. Easliy done by allowing some of the already cooled cabin air to be pulled into the rear side cooling vents on the side of the unit via a a duct or vent in the cabin/galley bulkhead and a window opened slightly to allow fresh air in. In a sense of diluting the cooled cabin air with some warmer fresh outside air. First the fresh air is good you and second it dilutes the air in the cabin just enough to allow the unit to (effectively fooling it into) run longer so dehumidifing can take place also. I have run my this way for almost five years in my teardrop and it has not let me down yet in humid South Florida.

[john]

Woody said:

The main concern is to remember to allow rear unit cooling air (side vents) and the hot exhuast air from the back of the unit not to mix. Allowing the side vents a separate cool air source is essential for operation. While directing the hot exhuast air out and away from the cool air supply is required to keep the unit operating normally. An increase in operating tempeture in the hot exhuast increases compressor head temps and pressure which makes the unit thermally shut down from overheating. The other thing to consider is that the units are designed for low restriction air flow so to restrict the exhuast air flow will cause the unit to overheat also. The fan that cools the back of the unit is design to push the air through and they are not strong enough to over come small exhuast openings Plus they are designed to operate with some condensate water in the pan. You will have to ensure that the unit can drain freely to prevent water slinging and water damage. Always tilt them back in your design to allow water flow so it can drain. Most people don't consider this and go camping and not allow for the unit to drain when they level a trailer. It is better to consider this during your build that have the unit flood your cabin and matteress during the night just because it wasn't level so it could drain outsde the trailer. Just my two cents worth. Good luck with your build

I agree that the A/C unit needs to breath and I had concerns with my design for that reason. The last few summers with 96+ degree heat combined with NC and SC humidity with no A/C problems cured that fear.

Actually I sould not say "no problems". I did have a problem. The A/C was too efficent for the tear. It would cycle off before drying out the air. I need that dry air down here in N.C.

Good accidents happen.... The first part of my first night camping was threatening to be miserable, but some time during the night an extra pillow made its way down in front of the A/C and blocked off the air intake across the evaporator. We woke up cold ...I tell you cold...the next morning.

I found that the AC would work better if I could lower the volume of air through it. It produces too much cold air for the small space. A slower fan speed would be nice, but a pillow or more recently a rolled up blaket in front of the AC seems to do the job of cooling the camper more slowly.


Good luck!!

[jp03]

sorry, old post got wipped out. Do not block the a/c air flow! Lets go A/c 101; Freon acts like rubbing alcohol. It goes into the cooling coil as a liquid, gets heated by the warm air and evaporates to a vapor/gas. Problem is that most window a/c units are made cheap. Cheap meaning, that a control valve for the freon flow could be installed, but never is. This valve would act like the carborator on a car, letting in only what is needed. Instead the window a/c has just a small hole, like a funnel in thimble size. Roughly speaking, the amount of freon cannot change how much is flowing into the coil. Design of freon flow, is for all of the freon to heat up to a vapor, before leaving the cooling coil. If the cool is blocked with a pillow, or anything, then there is a great chance of liquid freon going out of the coil and into the compressor. Science rule #1, liquids do not compress. So the liquid can damage the compressor of the window a/c unit. Compressor is the heart of the unit. Just a quick edume cation. Just open a window to create more of a cooling load.

[john]

jp03 said

Freon acts like rubbing alcohol. It goes into the cooling coil as a liquid, gets heated by the warm air and evaporates to a vapor/gas.

The freon, in fact, evaporates as a result of going from a high pressure zone to a low pressure zone in the evaporator as it passes through the expansion valve or orifice. It does not evaporate as a result of warming.

It would take some real cold unnatural temperatures for the freon to remain a liquid in the low pressure area of the evaporator and travel to the compressor in liquid state. No danger here. I don't see sub Siberian temps in my tear's future.


In my case the evaporator would freeze up long before a slug would make it to the compressor and I have had no freeze up at all. That is not to say, of course, that evaporator freeze up would allow temps to dip low enough to to stop the freon from evaporating. It would take temps much lower than that for freon to condense into a liquid in that low pressure situation.


Anyway my A/C works and without problem. Plus I was able to keep the windows closed during japanese bike week in Myrtle Beach.