AC Not keeping up

[Briank61]

Hello everybody, first I wanna thank everyone for being so helpful. I haven't figured out how to directly respond to a message yet. So my question is this when it gets very hot my AC units seem to have a problem keeping up? Has anyone else had this problem?Is there a fix? I have a 2015 Rw38GK15

[travelin' texans]

Define "very hot"! Anything over a 100 degrees without shade you'll probably be lucky to keep the inside near 80 with both A/Cs running nonstop. A couple portable fans in either end will help.
Realize you are trying to cool a 40' tin can with minimal insulation in the ceiling, only about 2" of styrofoam in the walls & slide ceilings & next to none in the floor.
However there are several previous post with ways to improve the air flow thereby helping the cooling somewhat, use the search function or the how to section.

[RickF]

I’m not familiar with the GK floor plan. On our 39MB we find it useful to adjust the ceiling vents based on the time of day and where we’re spending our time. Our forward bathroom is always closed off and so is the door. We use the day nightshades to keep direct sunlight out of the coach as well. Fans also quite helpful. We are Boondocked at the moment and able to put up sail shades to reduce the direct afternoon sun on the front cap. That made a big difference.

[XCMARK]

Last fall I was on the roof cleaning the condenser coil and installing Micro-air soft starters in both of my AC units. I found there was a 1" thick x 16" long piece of sealing foam that runs along a wood blocking inside the AC units discharge , this foam seals the cold air supply side off from the return air to the unit. 80% of the foam was pushed out and was letting the air short cycle from supply to return , this was constant of both of my roof units. The foam that was in the slot was all twisted up and would not stay strait so I replaced it and held the new piece in with caulking instead of the double sided tape the factory used that dried out and didn't stick any more.

You will need to go up on the roof and remove the outside plastic cover then remove the sheet metal cover on the forward side of the AC units , there is about 20 #2 philops head screws that hold the cover in place. You dont want to remove it 100% because there is a splice box for the 120 volt power and thermostat wires on the forward side part of the cover , its inside the return air inlet and held to the cover by wing nuts inside. Just peal back the back half of the sheet metal from the compressor side to the front leaving the front close to its original location. Chance are your going to see a black piece of foam pushed into the return air section , this is the piece your going to fix. It seals off supply air to return air to the unit. I would guess 1/4 to 1/3 the amount of supply air in my coach was going right back into the return section and never making it to the living space.

All the other comments above are correct , follow them . Pull your window shades , put out your awnings, try to find a side with afternoon shade , cover your window with UV see thru film. Be proactive and start your AC early AM and keep the doors closed (closits,bathroom). You can not keep a coach this side cool on 100* days in the sun without doing everything possible to help it. 90* days should be fine . I have two 15K roof AC and really if your down south you need 3 roof units.

[Ford truck guy]

There are several RW owners that have experienced this issue and took to home remedies to fix..

* - The vent collars were too long into the vents
* - The vents were NOT sealed between the HVAC duct and collar
* - The foam separator in the condenser had fallen over
* - The front cap had virtually no insulation between the cap and the shoe racks

On my late 2015/early 2016 I did the above fixes and was happy with my AC performance after... now that I have a 3rd AC, I have NO ISSUES with cooling.... It gets downright COLD in there

[Tom's38GK]

As Ford Truck Guy said I have a 2015 GK38 and I did all the things above because I had the same issues with the air keeping up. First there are 4 screws in each shoe box in your front closet. Remove these, then take out the boxes which will give you access to the front cap. I added 2 extra layers of the aluminum bubble insulation 14R total gluing it to the cap with 3M spray adhesive. After that stuffed a roll of 15R pink insulation between each side of the center box shelf area. Closet went from 125 degrees to over all coach temp. Big help. Then I pulled one of the vent outlets measuring from the top of the supply vent duct to the edge of the roof. Well 1/4 to 1/2 an inch was total crap..... at the same time noticing the open gap between the supply duct and ceiling where the cold air could be pushed into. Taking aluminum duct tape I sealed all the openings and cutting off the vent tubes I increased my air flow by 75%. At 95 degrees my air conditioning cycles. Hope this helps.....

Tom
North Texas

[74Retiredby47]

This is my 2nd Redwood 3941FL and this one has more black paint for starters. I am partially under a pine in Florida and I am not keeping it under 80 while set at 80. My kitchen and bedroom are the full height rooms and they're the ones struggling. They don't seem to turn the air enough so I suspect the system is not sealed well

[rob_fla]

I made all the changes some time ago posted by Ford Truck Guy plus a few more and our A/C performance is now acceptable all summer long.

1. Vent collars were too long into the vents, shorten the collar for better air flow
2. Vents were NOT sealed between the HVAC duct and collar, sealed vents so cold air does not leak into the attic space
3. The foam separator in the condenser had had fallen out, sealed with foil duct tape
4. The front cap had virtually no insulation (it had fallen down) climbed in front cap area of our 38FL and added insulation and secured it so it would not fall down (made a big difference in Front Living Room area)
5. Added ceiling registers (according to A/C manufacturer Redwood should have installed a minimum of 5 Registers per A/C unit (we only had 7 registers total, now we have 12 total, much better Air Flow / AC performance)
6. Added 2 additional returns on each unit and unblocked return area restrictions for better air flow / AC performance.

[mstan]

I have a 38Gk 2015 model. I have also done all the above mods. There is a sight that has pics of all the above mods so you can get a visual. That will help you a lot. One thing I have done also and it may have been mentioned. Is cut aluminum bubble insulation to the size of your windows. And then I used velcro strips to attach it outside to block the sun from penetrating those windows. No the wife doesn't like it. Neither do I. Looks Redneck! But it works. I also did the same for my AC covers on top. Again. doesn't look the best. But I am more interested in cool that looks. I already had cut this insulation for the inside of my windows as well. Don't forget to take your safe out and stuff the cavity full of insulation also for your closet. Or you can add an additional AC to your vent opening in the hallway of your shower and bathroom and stay cool. good luck!

[travelin' texans]

Originally Posted by mstan

I have a 38Gk 2015 model. I have also done all the above mods. There is a sight that has pics of all the above mods so you can get a visual. That will help you a lot. One thing I have done also and it may have been mentioned. Is cut aluminum bubble insulation to the size of your windows. And then I used velcro strips to attach it outside to block the sun from penetrating those windows. No the wife doesn't like it. Neither do I. Looks Redneck! But it works. I also did the same for my AC covers on top. Again. doesn't look the best. But I am more interested in cool that looks. I already had cut this insulation for the inside of my windows as well. Don't forget to take your safe out and stuff the cavity full of insulation also for your closet. Or you can add an additional AC to your vent opening in the hallway of your shower and bathroom and stay cool. good luck!

It's not that the A/Cs on RWs are junk, they're the same brand as about a100+ other brands of RVs.
I'll say that I'm quit sure that there's not a single HVAC technician at the factory installing them & I'll admit more concern could be given as how they are installed, but welcome to the rv world.
With the fixes mentioned here, that a good many of us have done some or all, it should keep your RW comfortable without all the redneck camouflage.

[piper guy]

I’ve done all the mods Rob mentioned and I’ll add one more that really works. We are in the Arizona high desert at Lake Powell. As I write this, it’s 104 degrees outside and we are sitting in bright sun, no shade.

Two summers ago I added EZ Snap sun shades to the coach. These are similar to the see-trough black shades you see all the time on boats in Florida. They are a cut to fit, outside application with snaps that stay on the coach. Snaps are available either screw in or adhesive. I used the adhesive ones and find that I need to replace a few each year but I’ll take the trade off for not drilling holes. Lol. These are see-through, does not turn the coach into a cave.

Short answer, they work. As said above its 104 now and will probably hit 106-7 today. Inside right now is holding at 77 degrees. The shades dropped the inside coach temp almost 4 degrees when installed. Not cheap, but worth the $$$. In the winter, they get rolled up and live in the truck bed underneath the can for the Roll n Lock cover.

ezsnapdirect.com

[mstan]

Originally Posted by travelin' texans

It's not that the A/Cs on RWs are junk, they're the same brand as about a100+ other brands of RVs.
I'll say that I'm quit sure that there's not a single HVAC technician at the factory installing them & I'll admit more concern could be given as how they are installed, but welcome to the rv world.
With the fixes mentioned here, that a good many of us have done some or all, it should keep your RW comfortable without all the redneck camouflage.

Danny, you are right. The AC units themselves are not junk. I would have been more correct in saying as you have. The design is junk. I am a former HVAC mech. myself. So I am passionate about a properly working AC. As for the Redneck camo? LOL! There is a better system but it is expensive. You can purchase a Sunshade material that is attached to the windows outside. And is much more attractive. But it is expensive. They also allow you to see out so as not to blackout the windows completely.

[74Retiredby47]

Couple questions since there's activity here. What are vent collars? Couple things to add for my scenario. I have heard on several occasions a sound in my ceiling that I'm guessing is ice hitting a fan and launching through a space in my ceiling. If it's not that it's a bump hard enough to make the debris the redwood builders leave in the ceiling. My first 3 trips with my 1st redwood dumped piles of sawdust from vents. I got the slide awnings which should help with cooling. My units are blacks and I should at least paint them white. When I push up my ceiling it does not budge so I'm guessing I'll need to access roof. On that subject will my ladder support 300lbs? No it won't. As far as AC vents I have 4 each section (bed, kitchen, living room) in the center and 2 returns each section at the outer edge. It is a 2019. My bedroom heat has never worked also. But each unit feels cool but air volume is lacking in places. It seems like a racetrack design meaning you can feel air in rooms that ac isn't running in

[bkseyer]

Did it all. Put foam in the front duct right after the air dumps.

[rtoon]

I have a 2013 36 RL. One heat pump and one AC. I have done most of the other suggestions and they have definitely helped. I have one more modification that has helped immensely. I have taken 2” painters tape and blocked all of the floor vents and gas furnace air returns. The furnace air returns under the bathroom cabinet and under the coat closet we’re closed off with tape and cardboard. Once this is done, the storage belly is not as cool since the cold cabin air is staying in the cabin and the hot storage air is not rising through the vents. Be sure to use painters’ tape to prevent injury to surfaces.

[Greg C.]

I have a 38RL and have done all the modifications that have been mentioned. I have seen an add-on called RV A/C Airflow which advertises up to 40% more airflow. It is made for units that can be accessed from underneath in the living area and is a deflector that pushes air into the ductwork. There are numerous videos on YouTube that shows the installation process. The problem would be removing the A/C unit from the roof to access the plenum and either installing their product or fabricating one. My unit only has two A/Cs and will not keep the temprature below 80 degrees if the outside temp is 90 or above.

[XCMARK]

Originally Posted by Greg C.

I have a 38RL and have done all the modifications that have been mentioned. I have seen an add-on called RV A/C Airflow which advertises up to 40% more airflow. It is made for units that can be accessed from underneath in the living area and is a deflector that pushes air into the ductwork. There are numerous videos on YouTube that shows the installation process. The problem would be removing the A/C unit from the roof to access the plenum and either installing their product or fabricating one. My unit only has two A/Cs and will not keep the temprature below 80 degrees if the outside temp is 90 or above.

We have a 2015 RL38 with a 15K and a 13.5K AC, I have done all the mods listed in this thread and a few others . This past weekend it was 91*f and zero shade other then my awnings out and it was 72* inside going in and out often. I had issue keeping it cool before I did some very simple check and changes to help . I would bet the bedroom closet and bedroom is warm in your RV. The nose cap insulation falls down and was only 3 1/2" thick bats in ours, Stuffing the cap with mineral wool will make a noticeable improvement. Opening the Sheetmetal box in the roof top AC and fixing the foam that pushes out between the supply and return air makes a big difference. Insulating the bathroom skylight makes a difference . putting the insulating pillows in the roof vent fans helps. pull the shades down during the heat of the day. make sure the AC is set to turn on at 70* don't wait until your hot.

[Semper Fi]

Great Info from all -
We have 2015 39MB and the same problem with AC not keeping up. I will definitely look at the system and correct / improve as needed.
Much thanks to all...😎

[shusfit@yahoo.com]

Hi thanks for the great information guys! Was wondering what the website was that showed the pictures? That would be very helpful for us newbies. Thanks very much.

[XCMARK]

I can confirm that one 15K AC on a 85* day with one side of the trailer in full sun I was able to keep it 70* inside . The second AC unit never came on with it set on 72* in the bed room.