A/C settings for T@G

Canoham · May 2019

Bought a used 2016 T@G a few weeks ago and have used it a few nights here in southwest Florida where it’s in the 90’s and really humid.

Does anyone have recommendations for what settings to use on the A/C and whether windows should be cracked or not, roof vent open or not, roof vent fan on or not, roof fan speed and direction?

We have experimented a little and were able to keep cool but humidity inside was pretty high. Thanks.

mgreen2 · May 2019

Make sure you are using the AC exhaust fan and set AC on the higher cooler setting. We normally have to turn the thermostat down because it gets too cold. I don’t open the fantastic fan or windows if it’s really hot because the AC will take the moisture out on its own. Have the front of the camper slightly higher so the condensation will drain out of the back of the AC platform

Canoham · May 2019

Thanks. That makes sense to me. I have read that you should crack a window open or the fantastic fan slightly but you don’t do that in your house so why in the trailer? In Florida the outside air is close to 100% humidity so I don’t see why you would want to let any of that in.

SueBHunny · May 2019

The T@G is a much smaller space than your house. Without ventilation your own respiration causes additional humidity.

LuckyJ · May 2019

While in orlando last august, we did set the ac to about 3/4 cold about mod speed and open the roof vent about 1/3 and maybe a bit for the side window, but not sure. Also like memtionned, AC fan on. W/O that fan, the foot wall will get very hot.

It is not perfect science.

You might have to eperiment a bit. And agree with @SueBHunny about the fact that a house as way more breating air than a small T@G trailer.

Canoham · May 2019

Thanks all for your comments. And SueBHoney I see your point too. I looked it up and human breath has 100% relative humidity! So in a small space that would be adding a lot of humidity. Oh well, looks like there is no ”standard” setting and we’ll have to keep experimenting to see what works best for us.

McNutty195 · May 2019

Hi all, have a related question:

My wife and I did a trip last weekend and the humidity was terrible outside and inside our new T@G. We were running the AC with the exhaust fan most of the weekend. I was also alternating between having the windows/fantastic fan running and having everything sealed trying to find the best configuration. Long story short the inside humidity was 75-99% the entire trip which wasn't great.

I've been thinking about getting a dehumidifier, but saw this post and thought I'd give the AC another chance with everything sealed up. So when I got home the humidity in the trailer was 79%. I closed all the windows, vents, and doors. Turned the AC on lowest temp and I think max cool setting. Had the AC Fan switch on, and even raised the tongue of the trailer above level to allow drainage. Checked it again three or so hours later and the humidity is in the 90s.

Can someone please help me figure out what I am doing wrong?

PS trailer is sitting inside our garage right now.

Michigan_Mike · May 2019

Crack the roof vent some to allow for some air circulation and the auxiliary cooling fan must be on too. Another thing that will help out is to locate the trailer in a shady location or minimize the sun exposure. Moving the warm air out is key, but closing the trailer up completely should never be done as people do emit humidity from breathing and a small fan inside the trailer that moves air around will help eliminate the condensation inside the trailer. Cracking the vent helps in this matter too. Irregardless of whether it’s hot or cold, to minimize condensation crack the roof vent. When you get up into 90+ temperatures the efficiency of the AC will drop as these are small units and coupled with s damp environment this makes it tougher to cool things down. Ryobi makes a small 18V fan that works great and also can be used on110V. They are wonderful fans and can be purchased at Home Depot.

McNutty195 · May 2019

Okay, I'll do another test with the fan vent cracked. Should I have the roof fan turned on and pushing air out too?

During the weekend trip we had all the windows cracked, roof vent open, roof fan on, AC on, and AC exhaust fan on for quite a while and couldn't get the humidity down. Granted we had 2 people and 2 small dogs.

However, during my garage test earlier today the humidity rose in the trailer by nearly 20% with just the AC and AC exhaust fan on, windows/doors/vents sealed, and nobody (people, dogs, or otherwise) in there.

Just trying to figure out a good solution for the next trip in a week or so. I'll look into the Ryobi fan. I'm also contemplating buying a small dehumidifier such as this: https://www.amazon.com/gp/product/B01DC5PPWM/ref=ox_sc_act_title_2?smid=A119Z83B95RD4O&psc=1 Any thoughts on that?

Michigan_Mike · May 2019

You won’t need to run the vent fan as you just want to allow a small amount of air circulation inside the trailer, thus the small cracking of the vent itself. An interesting bit of information we found out about 4 years ago from a friend who owned a T@B unit was that he had done some experimenting with his AC unit. On the T@B units the AC unit vents and intakes air out the side wall of the trailer and brings fresh air in. The issue here is that both the intake and exhaust are on the back of the AC unit, close enough that it sucks some of the hot air in through the fresh air intake of the unit, thus not allowing adequate cooling to take place. So if you look at the links below you will get an idea as to what people have done with the T@B units and how it is very similar to what is no doubt occurring with the smaller trailers.

I know of others who have used small dehumidifier units and if you have 2 people and 2 dogs inside the trailer it is going to add to the humidity obviously. If you can obtain good air flow (crack the roof vent "just a tad bit" and don't fully open it) this will help with cooling. I had spoken to Shawn, the guy who did the experiment in the first thread below and he said that once he obtained separation in the intake and exhaust he noticed that water began to drip beneath the trailer from the AC moisture exit tube from the AC unit as efficiency was obtained. Read the discussions as it should give you further insight. I would also encourage you to search that forum too for more information as others have been through the same problem. Good luck!

https://tab-rv.vanillacommunity.com/discussion/3564/air-conditioning-unit-change-out-part-2-ac-cabinet-modification/p1

https://tab-rv.vanillacommunity.com/discussion/7176/t-b-320s-air-conditioner-hot-weather-testing/p2

Fourman110 · May 2019

@Michigan_Mike said:
Crack the roof vent some to allow for some air circulation and the auxiliary cooling fan must be on too. Another thing that will help out is to locate the trailer in a shady location or minimize the sun exposure. Moving the warm air out is key, but closing the trailer up completely should never be done as people do emit humidity from breathing and a small fan inside the trailer that moves air around will help eliminate the condensation inside the trailer. Cracking the vent helps in this matter too. Irregardless of whether it’s hot or cold, to minimize condensation crack the roof vent. When you get up into 90+ temperatures the efficiency of the AC will drop as these are small units and coupled with s damp environment this makes it tougher to cool things down. Ryobi makes a small 18V fan that works great and also can be used on110V. They are wonderful fans and can be purchased at Home Depot.

By auxiliary cooking fan, you're referring to the ceiling fan?

BBsGarage · May 2019

@Fourman110 , No, there is a separate switch on the back wall that operates exhaust fans that evacuate the AC exhaust from the back of the AC out thru the cowbells on the sides of the trailer. You may want to be sure that they are actually "exhausting" there have been some posts claiming the fans were installed backwards.

rich67 · May 2019

I crack the roof vent and one of the windows, run the AC on high with the AC fan on, and have a wind deflector on my vent so it doesn't blow right on us when we sleep. I've found this to be the most comfortable option.

McNutty195 · May 2019

Thank you all! That is a lot of very good information. I did at one point take the exhaust fan panel out to look inside. Thought I installed it the right way, but maybe not. I will check that when I get home, then go from there!

HellFish · May 2019

Late to the game here. A/C should be removing a lot of moisture from the air and dumping it under the trailer from the drain tube. Is it? Put a container under your drain tube, run the A/C, and see how much condensation you are getting. If you are getting a bunch on a humid day, then venting and fan settings is your issue. If there is no water coming out of the tube, you have a drainage issue and the A/C might be throwing cold, but damp, air into your T@G. Which is it? (I ask 'cuz my T@G had a drainage issue.)

McNutty195 · June 2019

Okay, here is my next update. Sorry its long winded.

I checked the air output at both of the silver vents on the side of the trailer and couldn't really tell a difference between having the AC exhaust fan one way or the other. So I tried flipping it. Still no luck.

I've also now tried these following variations of venting:

Trailer completely sealed, all doors, windows, and roof vent sealed.
Roof vent slightly cracked, doors and windows closed.
Roof vent slightly cracked, and one window locked in the vented position, all other windows and doors closed.

All three of the variations were tested with the AC running at cooling level seven with the fan control set to three snow flakes and the AC exhaust fan switch turned on. All of these test occurred inside my garage as well.

I have confirmed there is condensation coming out of the drain at the bottom of the trailer. And still no matter what I do running the AC raises the humidity in the trailer to 90% with no one inside it.

I have now officially pulled the AC unit out of its little cubby hole. I've confirmed that the AC exhaust fan that I was messing with was the exhaust fan that directs air out the vents in the bottom of the trailer. It is now for sure blowing air away from the AC unit and down to that vent. Here is the part I need help with: I've also discovered that there are two other fans I wasn't aware of behind the cabinets. Those fans control the air moving to the silver side vents. They seem to be pulling air in from those vents and shooting it at the AC. Is that correct? Or should they be pulling air from the AC and shooting out?

Sorry, I feel really high maintenance with all of this, I just want a working AC haha.

Michigan_Mike · June 2019

No, that is not correct. The cowbells as we call them should be exhausting the hot air from the plenum area the AC exhausts to. So those fans should be blowing the air AWAY from the air conditioner. Another way to check intake and exhaust is to use a piece of Kleenex or toilet paper and see which way the air is flowing. In your case you can flip the wires and get the air flowing in the right direction and this should alleviate your problem.

WilliamA · June 2019

@Michigan_Mike said:
No, that is not correct. The cowbells as we call them should be exhausting the hot air from the plenum area the AC exhausts to. So those fans should be blowing the air AWAY from the air conditioner. Another way to check intake and exhaust is to use a piece of Kleenex or toilet paper and see which way the air is flowing. In your case you can flip the wires and get the air flowing in the right direction and this should alleviate your problem.

You can also just turn the fans around. They mount either way...
WilliamA

McNutty195 · June 2019

Okay one thing I want to double check though: is there not an intake fan of any kind? Looking at the manual for the AC it seems that the AC is supposed to take in fresh air from the sides and exhaust hot air from the back.

Based on that and looking at the physical configuration of the pathways for the air/fans I would think that the cowbells are air intakes rather than exhausts.

Just want to make sure as I want to make sure the AC gets the proper amount of Air.

Also, I read through the thread started by Hellfish and saw the extra condensation hole solution. I have drilled extra holes in the bottom of my AC and propped up one side of the drip pan, just need to get the burr off the holes then put everything back together.

LuckyJ · June 2019

@Michigan_Mike said:
No, that is not correct. The cowbells as we call them should be exhausting the hot air from the plenum area the AC exhausts to. So those fans should be blowing the air AWAY from the air conditioner. Another way to check intake and exhaust is to use a piece of Kleenex or toilet paper and see which way the air is flowing. In your case you can flip the wires and get the air flowing in the right direction and this should alleviate your problem.

@Michigan_Mike, can you check that with factory?? Caise I am with @McNutty195 on this, the info that I got, (do not remember where from but it was like an official comment) is that air dirculate from the cow bells down to the vent under the trailer. Even if hot air should be moving up. Probably because of the snorkel effect, to get clean air from high and evacuating closer to the ground.

Thanks!

Sharon_is_SAM · June 2019

@Michigan_Mike, I have a few questions. I know there are 3 fans located above and under the AC unit.
Do they all turn on with the auxiliary cooling switch?
Is the purpose of the single fan to pull hot, exhausted air from behind the unit down to escape under the TaG?
If the other 2 fans are designed to exhaust hot air via the cowbells, do they also help draw air into and around the AC unit via the inside vents along side the AC unit?

WilliamA · June 2019

Sharon (Sam? I'm so easily confused...)
Your questions are spot on and bring up an important (I mean "really" important!) point. It would seem that there is a lot of confusion/disinformation regarding how the aux fans are supposed to work. It would seem to me that for the 3 of them to be thermally efficient, they should work thus:
1.The bottom plenum fan under the /c should blow upward., drawing in cool air from under the trailer.
2.The cowbell fans should be set to blow air out of the cowbells.
3. The cabin vents next to the a/c unit "should" draw air into the plenum around the a/c unit and out through the cowbells.

That would make the best "thermal" sense since as LuckyJ. Said, hot air rises and having the fans set thus would precipitate already active thermal flow.

My own observations have shown that the cowbell fans are anemic at best, airflow wise and are hampered by having to force a lot of air through many twists and obstructions to do their job. That said, it would be more foolish to try and force hot air down. Especially since the bottom fan is just hanging in the plenum and can't possibly be very efficient.

If ever there was a thread that needed a sticky, this one should, perhaps with factory input on the design for airflow...

WilliamA

McNutty195 · June 2019

I agree. looking at the entire system from my perspective it would make the most sense to bring intake air in from the bottom, maybe sides, and/or the inside cabin. The Hot exhaust air should be evacuated up in some way, or at least out the side given that is hot air's natural direction.

My feeling is that the problems we are all having with the AC are caused by lack of proper exhaust and intake air. I'm guessing that hot exhaust air from the AC is "pooling" at the top of the chamber created by the insulated sheeting directly behind the Air condition unit. The back of the unit is where the hot exhaust air goes based on the manual, which means for it to work properly that heated air needs to be evacuated. Evacuating it down isn't great in the first place, but this is worsened by the fact that the only thing coaxing the air down is a single fan hanging in space.

I've now reassembled my AC unit and replaced it in my T@G. I did some testing last night with extra drainage holes in the bottom of the unit, the drain pan propped up to facilitate drainage, the tongue lifted well above level, and the two cowbell fans flipped.

It did work a little better. Now, rather than the humidity raising straight to 90% with nobody in the camper, it hovered between 60 and ~73% with me in it watching. That is a fairly substantial improvement, but considering I saw little to no condensation coming out the bottom, I'm attributing all of that improvement to flipping the fans. This indicates to me that the problem is in fact an air flow problem, the condensation pooling is just a symptom.

The improvement is very welcome as 70% humidity is a big improvement on 90-95%, but I will continue pondering and working on improving it as it is still not really acceptable. I'm thinking I may try to make a bracket/gasket of sorts with multiple fans to put in the place of the current bottom fan. Maybe that will help to "pressurize" the system and better remove the hot air?

I'd love to see some input from NuCamp on this. The AC unit is by far the weakest part of the trailer, and right now to me it looks like a borderline design flaw.

Sharon_is_SAM · June 2019

It would be interesting to note the air flow directions for the TaGs that have used the AC with success/satisfaction.

In a different thread, from last summer/fall, I spoke with Creed from nuCamp. He indicated that there was a fan designed to assist exhaust to exit under the TaG. This was in a conversation about the interior AC side vents. Now I wonder if one of the effects of that fan (along with the fans to exhaust thru the cowbells) is to draw air thru the interior AC vents.

Fourman110 · June 2019

Where’s the switch to this fan? As many times as I’ve been in my 2018 Boondock, I don’t remember seeing it. That said 4 times out of 5 were Boondocking in the Boondock.

LuckyJ · June 2019

@Fourman110 said:
Where’s the switch to this fan? As many times as I’ve been in my 2018 Boondock, I don’t remember seeing it. That said 4 times out of 5 were Boondocking in the Boondock.

It is at the feet, just over the matress, under the radio unit. If you have a thicker matress, it could be hidden. You might have to dig a little.

HellFish · June 2019

Deleted my comment, but you HAVE to say something...

HellFish · June 2019

Not to belabor the point (oops, too late!), but has anyone added a fan to the bottom vent to pull air out of the plenum (and perhaps aid the other three fans in moving air down)? I crawled under there and found that the vent has pipes and wires obstructing it, so a simple box with a computer fan in it covering the vent would not be a straightforward install.

Michigan_Mike · June 2019

https://teardrop-trailers.vanillacommunity.com/discussion/comment/5418#Comment_5418

https://teardrop-trailers.vanillacommunity.com/discussion/comment/5436#Comment_5436

Sharon,

I believe the fans come on when the switch is activated. They are not heat activated or anything like that. And unless things have changed, heat is drawn out through the cowbells and there is an intake (as noted) underneath the trailer.

HellFish,

Im not intending to call you out here but you were discussing this same issue back in 2014 on the LG forum.

https://golittleguy.com/forum/#/discussions

Search their forum for: Air Conditioner blowing hot air??? There is plenty of information there and it mirrors the information above.

HellFish · June 2019

Mike: My cowbells pull air INTO the A/C plenum and the computer fan UNDER the A/C unit forces the hot air DOWN and out the bottom vent. All three fans come on with one switch. The vents on the side of the A/C (in the sleeping area) do allow inside air to reach the sides of the A/C (the part of the A/C that ordinarily would be hanging out your bedroom window), but it is the fan UNDER the A/C that draws this air, not the cowbells.

Sharon: Yes I did discuss this in 2014 (I didn't know talking about a topic more than once resulted in being "called out"...what exactly is the statute of limitations on the sharing of information?). I responded to the recent posts because I was a little surprised to see contradictory information appearing AGAIN.

Some people are still insisting the cowbells pull air OUT of the plenum ("cuz heat rises afterall", they say), and that the computer fan under the A/C pulls air INTO the plenum through the bottom vent ("cuz the air under the trailer is cooler afterall, and hey, heat rises", they say). However, if you check the posts from 2014 someone claims the factory rep contradicted those "facts" and said what I described for my T@G was in fact the way they designed and built them at the factory (like it or not).

Now, fans can be wired backwards accidentally at the factory, vents can be taped over, and owners can reverse the flow of the fans as they see fit. However, when establishing a "baseline" for how the system comes from the factory so that folks can then trouble shoot and modify as they see fit, I think we need to be as accurate as we can be. That is why I posted on this topic again. We do get new owners as time passes, and they deserve useful (accurate) information as much as the rest of us did when we were "noobs".

McNutty195 · June 2019

@Michigan_Mike,

I agree with HellFish regarding the fan directions.

My 2018 outback model most definitely came with the fans oriented as they mention. Center fan blowing exhaust down and out the bottom. Two side cowbell fans bringing cool intake air in. Based on the way the window unit AC is supposed to function (outside fresh air intake on the sides, interior intake on the front, and hot exhaust on the back) I'd say this fan configuration is correct.

Not saying that it seems to work particularly well. I now have all three fans exhausting and the AC is running better, but I do believe the above is the factory configuration.

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