Window AC unit in pass through storage?

[Bono_B-1]

We bought a 2016 Salem 27RKSS two months ago. The temps in Texas make it too hot to enjoy though. We have a single roof unit and last time we went camping, the temps were 107 all day. We ended up driving to the local Lowes to buy a 10,000 BTU portable unit and vented the exhaust out of one of the sliding windows in the living room.

After seeing a video of someone ducting the exhaust tube through the wall into the pass through storage up front, I had planned to do that as well. Our bedroom is in the front so I planned to sit the portable unit on one side of the bed and run the duct through a hole on the front of the storage wall between the bed and the trailer wall (I have 21" there). The issue was going to be venting the pass through storage in a way that would keep bugs out as well as water. I had looked at several 6" PVC fittings and thought I had a workable solution. However, after looking to see if this had been done before, I came up with a different idea. A window unit will save space in the bedroom, though it will take up some of the storage space.

So on either side of the bed, the 'nightstand' portion in front of the closets is 21" wide and 23" tall. I have looked at a few window units that will easily mount there with only the front being in the bedroom. The efficiency and less power draw as well as being lighter all make the window unit seem better than the portable option.

I still run into the need to vent the pass through storage area but will likely just install a refrigeration vent with bug screen. Another option I thought of is to separate that portion of the pass through and insulate it with rigid foam board. Then I can just open the access door on that side when hooked up and using the window unit. The last area I would need to address is the draining of water from the unit. I think a tray tilted to drain water with a simple PVC cleanout fitting will work and allow me to just screw the plug in from the bottom when needed.

Has this been done before? I know most people who go this route just use a window like we did with the exhaust hose on the portable unit. I'd like to save the space and have a nice clean installed look from the inside. Also, our bedroom could use the extra AC an d we can run the roof unit for the main area and not utilize the ducts for the whole roof since they're not very efficient anyway. With the portable unit, we bought a large HD 12g cord to plug it in. With the window unit only drawing 6-7 amps, it may be possible to utilize the plugs inside without tripping the breaker.

Tonight I replaced all of the lights with LED bulbs and it is a noticeable difference...both in heat reduction from the lights as well as being much brighter inside. We bought 20 bulbs off of Amazon for $40.

I'm also going to try some Gila 3-in-1 Heat Reduction Platinum window film to see if it will help a little as well.

So has the AC mod into the pass through storage been done? If so, can anyone point me in the direction of pictures or details?

Thank you

[Jeff_and_Abby]

Something pretty similar has been done with TC's (Pickup Truck Campers) - the tub or bathtub, the part of the TC that slides onto the pickup bed and sits between the wheel wells, will of course have this dead space in front of the wheel wells. So, some would have access doors to use this as "outside" storage. It would wind up large enough for a small window-type air conditioner ... already draining into the pickup bed, and alreaedy exposed to the outside.

The only two things you really need to address are sufficient air flow for the condenser coil to do it's thing, and drainage for the condensate, both as you have already considered.

Good Luck !!!

[Bono_B-1]

I think I will isolate that side of the pass through storage and vent the access door. It is the driver side which is a smaller access door on the outside and I'll only lose about 30% of the pass through storage area.

For airflow I think venting the access door will work and I am thinking about a duct fan to keep the air flowing through what will be a small 2x2 area.

[Jeff_and_Abby]

Thinking about it ... the "inside" part winds up being pretty self-explanatory, usually the air intake through a filter, then through the evaporator and out a blower duct across the top.

The "outside" part ... on an awful lot of window units, the condenser coils run the full width of the back, with air intakes on either side ... but no doubt varies from unit to unit.

If you could figure out a way to isolate just the "exhaust", and then push it out to your vented access door ... maybe consider insulating the exhaust so it doesn't radiant heat everything around it ...

When you figure that you can often score the little window units for a hundred or two (at least end-of-season, they get stupid cheap) this makes sense if you are up to the duct work part.

Think you are into a really "cool" project on this one.

[830hvacman]

Gotta love Texas...
Is it possible to add a 2nd roof air in the bedroom? If your rig is only wired for 30amps, you could run a separate cord to the power pedestal outside using a heavy duty extension cord.
Good Luck and stay "cool".

[gswhite25]

Maybe a Lou reed dryer vent would work to keep rain and bugs out... put a screen in the vent to keep bugs out and install through an outside storage door.

[Scrapper]

Just a thought about using a window AC. Using a small ac in the range of 5200BTU or slightly more. You might be able to make a square duct to fit the rear of the ac. Using aluminum sheet for the bottom and coroplast for the top and sides. Make the bottom with about 1 inch sides folded up. Pop rivet the coroplast to the aluminum. Use window caulk on all seams. Insulate with foil covered bubble wrap. Using closed cell foam, make the duct fit snugly around the back of the ac and fit against the access door. Install a louver on the access door as you already suggested. You might have to make a shelf to support the bottom of the ac so the rear does not drop into your pass through.

One thing you have to take into consideration is the window ac's do not have a drain. The outside coils are made to sit in the water and the rear of the unit sits about 1/2 inch lower than the front so excess water drains over the back. At least the 5200BTU one I have in the bedroom of my house drains that way.

Depending on how far your installation is from the access panel you may not need to worry about the water sitting in the aluminum tray. The heat from the rear may be enough to evaporate it. If not then you will need to figure something out to divert the excess to the outside. Maybe a small tray like you already suggested.

Hope I have given you some ideas. Reading your post got me to thinking.
Yea, I know, DW always tells me "there you go, thinking again". Sometimes my thinking gets me in more trouble.

[pirate53]

I'd beware of creating a mold and mildew environment.I think it would be tough to keep control of the condensation the unit would be putting out.

[TitanMike]

Originally Posted by Bono_B-1

The last area I would need to address is the draining of water from the unit.

On modern, energy efficient, window units, they use the condensate to increase the efficiency of the condenser. As the condensate accumulates in the bottom of the unit a portion of the outside fan shroud allows water to be sucked up and sprayed on the condenser coils. Better heat transfer to the passing air and the evaporation process itself actually cools the condenser coils.

All you will need is a tray like one can put under a dishwasher that has a side drain then route the hose/pipe to a point where it can drain directly outside.

I'd mount the unit with the condenser as close to the outside as possible and if behind a storage compartment door make sure it's open before running. As an alternative, perhaps add some shutters to the door like are used for gable mounted attic fans on a house. Then add enough material that forces all air through the condenser directly to the shuttered vent, not allowing any to escape back into the storage area. From there it's just a matter of separating the cool air from the return area in the storage area and any air direction construction you want to add. A large box (plenum) to collect output air with heating duct hose to send the cool air out of the storage area and a grill to allow the hot air to return to the A/C.

Since all controls are usually mounted directly on the front of the A/C unit you might just set everything for "MAX" and then use a line thermostat that turns the unit on when temp rises and off when you get cold enough. Those install between plug and receptical.

[m2kamp]

We just got back from our weekend trip. 100 degrees in the shade yesterday north of Houston according to our digital thermometer.

We have one 15k Dometic ducted roof a/c and it kept our TT at 74 degrees. But, I have the following mods:

-Reflectix film in dining and couch windows (don't really care to know neighbors business in an RV park or vise versa).

-Reflectix in entry door window.

-20% window tint in front bedroom windows and bunk window.

-Retaped the poor factory ducting and a/c divider job.

If our RV was any bigger though, I'd want a second A/C