Air Conditioning unit change out part 2, AC Cabinet modification

Pop-T@B

This is one of the first modifications I did when we first bought our T@B, I too like the idea of a digital thermostat and the remote control. The unit works great and keeps the T@B cool, but could always be a little cooler on those really hot days like it was at Tearstock this year. This was the first time we had our T@B out in the blazing sun with no shade and very high heat, The AC ran nonstop the whole time. It did keep us cool, but would have liked a little more cooling.

 When I did the change out last year, I just pulled the old unit out and put the new one in, just like Michigan Mike did in his post and never gave it anymore thought until I looked at his pictures (Mike I lifted one of your pictures to use in this post, thanks!). Then I understood why the plastic drip pan and the sides of the wooden AC cabinet get hot and radiates heat back into the T@B, which adds additional cooling load to the AC unit. This happened with the original unit as well. There is no insulation on the inside of the cabinet walls or the underside of the plastic drip pan. When the AC unit is running it puts off a lot of heat, most of the heat and hot air are expelled out of the rear of the AC unit thru the AC vent, the rest of it heats up the AC cabinet and the inside of your T@B.  So the next step was to pull the AC unit back out and see about adding insulation to the cabinet. It was fairly straight forward, I used ½” ridged foam board insulation, the foam I used has a foil backing on one side with an R value of 3.3. I just measured the spaces on the inside of the AC cabinet and glued the panels to the inside of the sidewalls and the front of the cabinet. Please make sure to leave space under the side panel with the AC drain hose, do not block the water flow and make sure to clean up all small pieces of foam. You do not want to leave anything in the drip pan that can plug the drain hose down the road. I did not put anymore insulation on the top and back panel, they were already insulated.  For the plastic drip pan, I cut a piece of foam board to fit the underneath side of the pan, you will be able to see this piece so I covered it with some fabric I had to dress it up. Then just glue the foam panel in place to the bottom side of the plastic drip pan. Then reinstall the AC unit. I ran the unit for almost two hours when I was finished and the sides and bottom of the cabinet did not feel hot like they did before. I know this is a lot of work for a small amount of insulation, but I feel every little bit should help.

Pop-T@B

Boo,

 My T@B is also a 2016 Max S and yes the drain hose is on the right side of the AC if you are facing it. You cannot get to the drain fitting without first removing the AC unit if you need to clean it. Also the hose does not drain into your gray water tank, if you look underneath your T@B near the tire on the left side you should see a short hose sticking thru the panel covering the bottom of your T@B, this is the drain for the AC 

Tabaz

Just an minor clarification - the computer fan in the roof vent directs air into the cabinet to supply fresh air to the side vents of the A/C unit.  I confirmed this with Ed from PV when I had to remove my A/C from the cabinet.  I imagine that is why the factory added those aluminum baffles with the metal tape - to keep the hot exhaust air coming out the back of the A/C from mixing with the cool fresh are from the ceiling vent and sides.

jdargis

In another post, it was mentioned that if you removed the bathroom mirror, there is a hole behind it, which has access to the drain hole.  Plus, if I recall, there was a picture.  The negative to this access, is the mirror has a caulk seal on the back and water from your showering could leak behind, if you don't recaulk the mirror.  Not an issue, if you are using only the toilet and not the shower.

Pop-T@B

I agree on the fan, it does pull air in. Even with this fan on it does not pull in enough air to keep the AC unit/cabinet cool. The AC unit gives off a ton of heat and with no form of insulation around the cabinet it gets very warm on the sides and bottom. This is putting heat back into the T@B and increasing the cooling load on the AC unit and on very hot days the little 5000 BTU AC has a hard time keeping up.

The AC unit the Factory installed in my T@B has a smaller/shorter frame and does not extend all the to the back of the AC cabinet, and would need those baffles to direct the hot air out, the new AC unit I installed is longer/deeper and when installed it touches the outside wall and there is no need or room to install baffles. I

Tabaz

Agee with the fan opening being way too small to adequately provide fresh air to the A/C.  This means it must draw more air from the outside grill on the side of the T@B.  This seems like a a really poor design because the hot air exiting is using the same grill as the fresh air coming in.  How about POP-T designs a slide out for the A/C?  Tucked in the cabin while not in use, but slides out the side to expose the unit when in use.  Get those wheels spinning Shawn!

Tabaz

Or at least a directional grill for the outside? Center louvers point straight out to exhaust the hot air while the two side sections point to the sides for the fresh air.

Pop-T@B

I agree, there should be a better way for fresh air to enter to the AC unit,I will start thinking about it. It may be as simple as installing a 12v high output fan in place of the factory fan. I do not feel like taking my AC out again, so the next person that has theirs out, please make note of the model number on the fan and send it to me.

Thanks, Shawn

Pop-T@B

 Hey OutbackAZ see if you like this idea. I bought these at Lowes for $1.78 each. I glued 4 metal washers to the grill cover so the magnets would have something to hold onto since the grill cover made out of aluminum. You can feel the AC pulling cooler air in from the sides, if you hold a piece of tissue paper close to it you can see the air flow being drawn in from the side, with the deflector removed the paper drops down and the air is now pulled from the center of the AC grill. The only draw back I see to this is if you forget to remove them before you head  down the road you will need to buy a new set. From the testing so far, it really should improve the AC cooling. Will need to wait from a really hot day to test out 100%, this is really a low cost solution and very easy to do.   

Tabaz

Occam's Razor Shawn!  What an inexpensive, simple and effective solution.  For the truly ADD among us, gluing the magnets behind the face of the grill would be a plus.

Pop-T@B

I tried that first with some small neodymium magnets I had, ( I know, who has those just laying around ) they just didn't have enough holding power to the small amount of metal on the air deflectors. I would have rather done it that way for the better finished appearance. I did paint the washers so they match, they really don't look that bad and you have to be looking from them to see them. I ran the AC for 20 minutes the inside temp dropped from 86 to 72 and I have never had the amount of water running from the drain like I had during the test, it was a steady trickle of water. it seams to really make a difference.   

jdargis

Do you think they will stay put in a driving rain and wind storm.

Tabaz

So looks like the optimum T@B air conditioning system consists of (1) the new electronic Frigidaire unit, (2) additional insulation around the cabinet and (3) the addition of the plastic deflectors.

Tabaz

Oh, I just noticed you painted the white grill a color to better match the side.  Nice improvement.

Pop-T@B

they hold very well to the metal washers, but won't know for sure until I have them out in a storm. I am not to worried, for only a $1.78 each I am going to get an extra set

Outback AZ,  I would agree on the last two points,  the first point on the new electronic AC is a preference thing, I don't think it works better at cooling, just nice to be able to set the temp to what you want.

Photomom

@Pop-T@B, there is a gap between the edge of the deflector and the back of the A/C unit. Any thoughts about how that could be sealed?

What did you use to glue the washers on?

Ratkity

There's 3M magnetic strips with sticky on one side. About the size of the magnets on the deflectors!! Amazing. Great mod!!!

Pop-T@B

I used Gorilla Super Glue on the washers, its what I had on hand. I think epoxy glue would be better. The only gap is the width of the louvers, its so small I did not feel it needed to be sealed off.  

I was thinking of using Velcro or the magnetic strips like you suggested. My only concern is the adhesive letting loose when it gets hot from the sun and or the heat off the AC unit.     

Photomom

This is a good mod and very timely as I have this on my to do list. I was planning to make some kind of baffles from corrugated plastic as someone mentioned doing, but I like this approach much better.

I am thinking of trying command picture hanging strips to attach the baffles as I have some on hand and they hold really well. Not sure how they will hold up outdoors but there is only one way to find out. 

SweetlyHome

Nice mod, it seems so many of the AC problems may be attributed to the unit drawing hot exhausted air right back into itself.  

jdargis

Also, an air deflector in the interior over the cooling outlets, makes a world of difference in cooling the trailer.  

Photomom

I bought a couple deflectors, just had a big rainstorm so the outside mod will have to wait.

I've noticed gaps between the sides of my air conditioner and the wooden trim. On my first trip in May when it was chilly I noticed cold air coming in around the A/C. That probably doesn't help with cooling, and it might be a source of bug infiltration as well.


Today I pulled the trim off (two screws) and put weatherstripping (the kind you use on leaky windows) around the air conditioner. I left it a little proud so the trim would compress it a little and seal it up.


Put the trim back on and I can't see light around the A/C anywhere!

A question: Cold air comes out the top section (red arrow). I assume the lower section (red rectangle) is an air intake from the T@B's interior. If I put some kind of deflector on the top section (actually requested by DH because cold air blows right on his side of the bed) won't that just deflect the cold output air right into the intake? I can see the thermocouple inside the lower part; if colder air comes in, won't that trick the A/C into thinking the T@B interior is cooler than it is?

jdargis

Make your deflector adjustable.  That way you can blow the air down where you want it.  Mine is made from hobby plywood and is attached by Velcro.  I haven't had the time to make small adjustable legs, so I adjust with pieces of Velcro.  Also, it cools the unit faster, then I remove it and use it when necessary.

Photomom

Also, if there is an air intake from the T@B's interior, why is it necessary to draw air in from the outside at all? Wouldn't that air by definition be hotter than the air inside and therefore harder to cool?

Photomom

@jdargis would it be possible to post a pic sometime?

jdargis

Photomom send me your email address to lawrencedargis@gmail.com  I am totally clueless on a computer and picture loading isn't going to happen in my life time.

Tabaz

Photomom said:

Also, if there is an air intake from the T@B's interior, why is it necessary to draw air in from the outside at all? Wouldn't that air by definition be hotter than the air inside and therefore harder to cool?

I believe these are two different environments.  The "outside" air is not supposed to mix with the "inside" air.  The air intake on the face of the unit takes in stale room air, cools it and returns it to the cabin through the upper vents.  It keeps recirculating the same cabin air.  The fresh outside air is used to circulate over the condenser coils which removes the heat.  It is then exhausted out the rear of the A/C unit.  I may be wrong, but is sure sounds plausible.

SweetlyHome

Photomom said:

Also, if there is an air intake from the T@B's interior, why is it necessary to draw air in from the outside at all? Wouldn't that air by definition be hotter than the air inside and therefore harder to cool?

 The air drawn from the outside normally does not enter the T@B unless the "Vent" is opened on the AC control panel, assume you have this feature.   Normally all the air drawn in from the outside is used to cool the condenser coil and blown back outside.  The same holds true on the inside of the T@B.  On a hot day I'm always sure to make sure this closed as it tend to rattle open in travel.

I believe the temperature drop of 15 to 30 degrees, several sources with slightly different numbers,  applies to the inside air.  Air drawn in at 90 comes out cooler, next time around it is cooled some more assuming it is not warmed backup a lot by the environment in the T@B.  Our 5,000 Btu (the unit can remove 5,000 BTUs of heat from T@B per hour) units are roughly equivalent to 1500 watts removed per hour.  I.e. a typical electric frying pan is roughly 1500 Watts.  Operating this and you living in the T@B will overwhelm our AC units leaving the sun out of it.  My experience holds this true.  

Also note that most window units are designed to operate. per the ASHRE  (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standard I read, in a 102° outside environment.  When it gets warmer than that efficiency drops significantly.

Photomom

@OutbackAZ and @SweetlyHome, that makes a lot of sense.

Where is this "Vent" you speak of?

SweetlyHome

On my unit, it consists of a little door in the wall between outdoor and indoor portions of the AC unit.  There is a small handle that you push/pull to open/close it.  Can't remember now which is which but I think its pull to open?  I have a Friedrich unit.

Photomom

Ah, I have a Danby, which if going in T@Bs now. No sign of a vent control.