Interesting AC problem

[mikeschn]

We tried to camp out in the Winter Warrior Friday night... problem was, the AC wasn't cooling the trailer down.

So Saturday we picked up a new window unit, and installed it into the WW.

Saturday night we grabbed our ballast (beer) and the dogs, and settled down for a long summers nap. But the new AC didn't cool any better than the old one did. The AC would run for a few minutes, and then cycle out.

What the heck?

So feeling around in the inside of the box where the AC is installed, the sides were cool, but the top was really cold. So is there a sensor in the AC somewhere that is picking up the temp inside the box?

Let's find out...

I cut a big hole in the top of the box.



Immediately the AC ran longer! So now I am thinking about cutting the right side of the box off too.

Did anyone else have this problem? I seem to recall that Len built something similar in one of his filon covered trailers...

Mike...

[Vedette]

We are back from our trip, with plans of changing our A/C also!
Good Roads
Brian & Sandi

[pchast]

In the box you are recycling the air. You need to allow the air streams to separate.
Can you duct the cooling (outlet) air higher with a flexible duct? You said the AC
units were new. Have you checked the filters?

[Donutboy]

Mine has a similar installation, but the way mine is constructed I have about six inches of space above it. I have not noticed this problem.

[mikeschn]

Okay, I cut off the side... air flow seems pretty good now... Let me monitor it for a while and I'll let you know if it's any better...



Mike...

[Verna]

Mike, my Little Guy Silver Shadow has two 4 inch vents, one on each side, in the cabinet space in the cabin. It also has a fan assist out of the 6" plenum that is behind the A/C unit. This directs the hot exhausted air out the two side vents high on each side. The A/C also pulls air from below the floor through two 8"x16" vents mounted under the floor. I've only used it 3 times and it cools the cabin quickly. I can take some pics if you want.

[jonw]

Mike - is it possible the lack of air space was causing it to get so cold that ice was forming (or a sensor thought it was) and it was shutting down and re-cycling? This is not uncommon for heat pumps (when in cooling mode).

[mikeschn]

Verna,

Yes, I'd like to see some pics of your setup...

Mike...

Mike, my Little Guy Silver Shadow has two 4 inch vents, one on each side, in the cabinet space in the cabin. It also has a fan assist out of the 6" plenum that is behind the A/C unit. This directs the hot exhausted air out the two side vents high on each side. The A/C also pulls air from below the floor through two 8"x16" vents mounted under the floor. I've only used it 3 times and it cools the cabin quickly. I can take some pics if you want.

[Verna]

Mike, here's some pictures:

Prophetstown SP June 2013.jpg (113.3 KiB) Viewed 1596 times

Another view of Angel Wing.JPG (92.59 KiB) Viewed 1596 times

Better pic of interior AC vent and fan switch.JPG (90.74 KiB) Viewed 1596 times

The "Angel Wings" cover a 4" simple round vent like what you'd find on a shed. Behind the Angel Wing is a 6" plenum that goes the full width of the TD and the full height also. You can see the round vent next to the A/C unit in the cabin, with the plenum fan switch near it. When you turn on the A/C, you're supposed to also turn on the fans so the warm air is exhausted through the Angel Wings (as you're driving along, the side view of the covers look like Angel Wings).

I'll post a picture of the A/C in the wall on the next post....only 3 pics allowed.

Sorry, I didn't get on the garage floor to take pics of the vents under the TD....if you really, really want to see the vents and the drain tube....I guess I could take the pics

[Verna]

I hope this helps, Mike.

Cabin cabinets and air conditioner.jpg (88.56 KiB) Viewed 1596 times

[working on it]

We tried to camp out in the Winter Warrior Friday night... problem was, the AC wasn't cooling the trailer down.
The AC would run for a few minutes, and then cycle out.So feeling around in the inside of the box where the AC is installed, the sides were cool, but the top was really cold. So is there a sensor in the AC somewhere that is picking up the temp inside the box? Mike...

You were having a problem with feedback on the "cold" side of the A/C, whereas I had a prolonged bout with feedback on the "hot" side. These window units were made for more open conditions than we give them in little trailers , I guess. There is a sensor behind the filter that tells the unit when the temperature reaches the desired level...in your case, inside the box. I use remote sensors for my home window units, so that sensed temperature level is from the middle of the room, not right at the unit itself. In my case, the exhaust temperature was fed back to the unit too well, the heat transfer of the Freon was interrupted by being too hot, and the unit would cycle off also. Glad you fixed your problem so quickly...my fix took 2 months.

[Jiminsav]

Mike, there should be a thermocouple visable in the lower louvers of the front of the A/C..this tell it when the return air is at temp and shuts it down, with yours inside the box, the air was coming out and immidiatly going back into the return section, causing your grief.

[2bits]

Mike, I can see how having the AC set back in the box a little could cause that problem, it would be intaking the cool air only from that box and not getting enough of the warm air from the rest of the camper. Now that you opened it up a bit, I wanted to suggest to get more separation between warm air intake and cool air output to get an AC unit like the last photo Verna posted where the cool air points up instead of forward. This might make an additional difference. Luckily, they are the cheapest ones available at the box stores and wally world too. Glad you are getting it sorted out!

[starleen2]

Mike - I had the SAME problem with the ladybug - I tried to get one more shelf above the air conditioner before the hinge joint. I removed the shelf and all worked fine

[working on it]

Mike, I can see how having the AC set back in the box a little could cause that problem... get an AC unit like the last photo Verna posted where the cool air points up instead of forward. This might make an additional difference.

I have an upward facing output on my A/C, but in my case, it needed to be directed forward (as to not go straight to the ceiling). I used a floor vent airflow director (plastic, adjustable) to straighten the flow. If you had this on the output section of your A/C, directing the flow up and away, then you could still have the box surrounding the intake section.

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