A/ C Condensation

newell

     We have a 2017 T@B S.  It finally got hot enough to turn on the A/C.  Since I'm one of those people that has to know everything about every system, I knew that there was a drip pan under the A/C unit and it had a drain tube that led to the ground below.  After a couple of hours with the unit on high, I looked for a puddle under the camper but it remained dry. Of course I thought the worst and suspected a clogged drain.  

     I check the forum for similar problems and found leveling the trailer just slightly forward and toward the door was the best position for draining. No water.  I then went on to read that the drip pan was accessible behind the bathroom mirror so I took that off and found the pan bone dry.  I poured some water down the drain hole and it drained perfectly.

     Here is my question: Since the trailer started out with a temp of 107F and was brought down to 77F after a couple of hours I think it's fair to say the A/C is working.  So,,,, where is the condensation???

 

Photomom

We've run our AC for 6 days straight now and not a drop of condensation. Days have been ~95, low humidity. 

JustJohn

Not one drop has ever come out of the drain tube of my 2016 Outback and I live on the hot humid Carolina coast. It is a curiosity, but the lack of condensation seems to be common amoung the members of the forum. 

Michigan_Mike

The 2017 is unique in that the newer drip pan construction eliminates the former problem of the pan overflowing into the trailer and the need to tilt the nose of the trailer if you will.  Since air is being sucked in and expelled from the trailer some owners (e.g., Pop-T&B) have found that by installing a small louvre style deflector on the outside metal grate of the AC unit  he was able to create some separation in the intake and exhaust of air from the trailer via the AC unit and actually established a more efficient air flow (both in and out) to the AC  unit, the AC unit cooled the trailer better and he was able to actually create some condensation drip below the trailer itself. 

 If you search his postings regarding the air conditioning unit you will find some of the information he posted up about a year ago.    My guess here is that since the difference in the temperature of both air flows is similar, this cuts down on the amount of condensation that is produced by the coil of the air conditioning unit itself and therefore there is no noticeable amount if any, of water coming down through the pan (and drip tube) of the trailer and outside tithe ground.   I spoke to him about it and he said that the vent he installed on the outside to separate the intake and exhaust did make a significant difference, cooled the trailer better and created a drip below the trailer.

Sharon_is_SAM

So Mike, in essence, the A/C dehumidifies better when the deflectors are used?

Michigan_Mike

SAM said:

So Mike, in essence, the A/C dehumidifies better when the deflectors are used?

Yes

Pop-T@B's makeshift plastic louver that is attached outside his intake/exhaust grate provides a separation between air that is expelled (via the AC unit) or exhausted from the trailer, allows the AC unit to run more efficiently and thus cool better according to Pop-T@B and the experimenting he has performed.  Otherwise there isn't sufficient separation between the cooler air coming in (lets say) and the hot air being pushed out through the AC condenser (I guess that's what it's called?) and the heat quickly dries up any moisture that is created.  

The small black intake port on top of the trailer (it's about 2" wide) provides some air flow too, but when Pop-T@B added the plastic louver to the outside metal grate it provided just enough air separation that the unit actually became more efficient, he was able to cool the trailer down even more and he created condensation or as you noted above, a dehumidifier type effect and dripping underneath the trailer via the exit tube from the tub under the AC unit inside the trailer.  In effect the AC unit without the plastic louver (and rare earth magnets used to attach it to the grate) is sucking in outside air and also taking in again some of the exhausted air, thus reducing the AC units efficiency.  

I discussed this with him and if he reads this he will no doubt add to the discussion.   I'm guessing that if someone was handy with and familiar with the operation of these small window style AC units a viable vent cover could be fabricated and substituted to achieve the same thing and without the need to attach magnets to a plastic louver that you can buy at Home Depot, etc.  My concern would be rain entering the AC unit, so a proper design would need to be put into place that would eliminate this problem, yet allow someone to manipulate the louvers to provide efficiency/cooling and protect the trailer interior.  

Tabaz

The A/C is a run-of-the-mill residential window unit designed to be stuck in the opening of a window with its cabinet sticking out in the elements.  The side and top vents take in fresh air while the large rear vent expels hot air.  When this same unit is stuck inside a cabinet, air separation becomes a problem.  That's why you see that aluminum tape and baffle at the back of the unit on the T@Bs.  Pop-Tab and Dale came up with a great solution for keeping the two airstreams separated.  Just my 2 cents.