Major RV Air Conditioner Upgrade and Improvement for under $35! 

In the commercial ductwork business you just created a "turning vane". Turning vanes are used in large supply ductwork on the 90 degree turns. This creates a smoother flow of the air and reduces your friction loss if you left the 90 degree turn as is. This type system has been around for many years but the RV industry does not care about what happens when the unit leaves their assembly line. I think it looks great and I have used Aluminum duct tape for years. Very strong. Great idea to show the DIY RV world.

I've done 4 of these. My sister helped on 3. I found that pink insulating "foam board" from big box hardware store was best bang for buck. I started with 1", and eventually found 1/2" was easier to work with. 1 4x8' board is less than $30 including a roll of good aluminum tape. I did it to all 3 ACs in our 5vr toyhauler. What I notice the most is the bed room is now way colder, and runs less when the main unit is running. Bedroom is also much quieter. Main is also quieter- we used to have to turn the volume up on the TV when the compressor kicked in.

I’m still “new” to RVing, saw this mod a few months ago. Did this to mine and it made a WORLD of difference as well as making the overall sound of the unit way quieter.

I just viewed your video and I wanted to post 2 comments. 1. The air dump vents need to be sealed so no air can be sucked in unfiltered. 2. Periodically check to see if your evaporator coils stay ice free which is an indication that not enough air is going at a sufficient speed.

I did this on my Chaparral 360IBL along with resealing the duct vents. It made a HUGE improvement! Prior to sealing everything, when it got to 100 degrees outside, it was 87 degrees inside the RV!!! It was HOT!!! After doing all of the work, inside it now only gets up to 77 degrees! This is with dual 15k btu air conditioners.

Several other channels have measured air flow before and after installing the $150 product. They show between 40%-100% more air flow. I like this easy less expensive option. I have been wondering about making something similar. Thank you for figuring it out for me. This video is a big help!

I did this mod a few weeks ago on both A/Cs and was shocked at both the increased air flow and the reduced noise level. Works on Dometic style a/cs as well.

I’ve watched several folks do this mod and I like the way you did it the best of all of them. Now time to do mine. Thanks!

Cool idea just remember when you open the old supply dumps you dont have a filter in those portions

I bought the kit from RV Air Flow, and installed it in my travel trailer in the middle of this summer. I couldn't BELIEVE the difference!! I had bought a supplemental A/C unit (rolls around on wheels) for the bunk house. After installing the kit to direct the air flow, I no longer have to use the supplemental A/C. Not to mention, my ducted A/C is HALF as loud as it used to be, and cools twice as good. It had no problem keeping up with the 95⁰ heat. Yes, I spent about $200, but I would do it again in a heartbeat. Money very well spent. Took less than 10 minutes to install.

I am doing the foam etc, but I did a upgrade that was really cheap and works excellent. Found a 4 inch inline duct fan, looks like big PC fan. In my primetime tracer I have a duct in the bedroom that doesn't push much air since its on other side of trailer. So I installed the 4 inch 6 watt duct fan that has adjustable speed knob. My bedroom has a plug in less than 6 inches from duct. Also the 4 inch duct fan bolt holes line up exactly same as the duct in trailer, so no extra holes needed. Just remove the cover on vent and install, was 5 minutes and works great. Cost was less than $30. Even on low blows much more cold air, on high it pushes crazy air.

Grand Design made the RV Airflow (what you are mimicking) standard in their fifth wheels. I added it last summer. It increased my airflow by over 40%, yes I measured it with a wind turbine. So this is an excellent idea.

I like the way you did it better than the way everybody else has done it because you get more air returned to your AC And what a better way to have your AC run more efficient by getting more air flow back to it

I did this right before labor day weekend. The air flow difference was very noticeable. Definitely worth the money

I got to say I really like that upgrade. I bought the material to do this about six months ago and just haven’t got around to it yet. I’ve seen the results of this done several times a few times actually in real life and I got to say this needs to be an industry standard. Again it doesn’t have to be beautiful it just needs to work properly. And I know from my buddies RV this helps a lot. Probably 30% more air running through his vents than straight from the factory.

I would pull down and re tape the divider in place at least (Bedroom one). Then I clean up the wiring and tape it to the side to allow smooth flow of return air. I noticed on mine the duct hole is partially obstructed by the divider, so re-positioning the divider helped. I also pull down the vents, skylights and fans in the kitchen and bathroom and tape those attic spaces to keep heat from the attic just radiating through the plastic.

I used a free 5 gallon bucket 🪣 cut it up with a grinder disc. Same design as you but with curved shapes!

We did out bedroom ac also. You won't need the dumps anymore. We closed 3 of the vents in our room because it was freezing us!

What a simple and cost effective DIY! Thanks for the video!

Kind of like porting heads to match intakes, smoother flow chambers. I have triangular foam from a military radio box that would have been perfect for this project. Just apply aluminum tape to the surface. I’m not sure how you could show this improves things, but I’m sure it does. You can get foam that has aluminum skin on it, it would be perfect for this project.

This posted a day before my birthday. I know what I'm doing tomorrow. Thanks JD

For applying the tape when it's a cooler ambient temperature or let's say when you have had your AC on, hold your hand on it for an extra moment. The heat from your hand will help active the adhesive if it's cool.

JD , I did a mod like yours on my Motor home a while ago, I couldn't believe the increased air flow and a quieter AC. I used the foil backed foam board I had in the shed and AC foil tape. I only have a single AC unite . Now I don't have to turn up the tv when the AC comes on.

I did something like this to, to our coachmen 281rlds back in May, it made a big difference in cooling down the trailer and it cost me less then 10 dollars, I had some packing foam already 😉 it worked great all summer, 3 times better than Last year...

good tip... I bought the RV Air one, not cheap but easy and helps a small business..

I did it and it's incredible. I also built a trim and installed a 16x16 filter back return air grill. My air flow and dust problems air fixed.

Thanks for the idea and video!!! Today I did this modification using the exact materials recommended. I'd been eyeing the RV airflow system, and not sure if I wanted to spend that kind of money. This DIY method probably took me a little over an hour, and I used two of the 7 EPS Polystyrene Sheets that came in the package. Don't know if I'll do the bedroom AC. Going to see how this main AC unit pans out as the temperatures warm up here in southern AZ in the coming weeks/months.

Awesome JD. I think it's nicer than the store bought. Thanks for detailed install video. I'm gonna do the same mod off your direction.

Just get an RV Airflow insert, 5 minutes and you're done and on to the next project. I did mine before heading to Rockport, works great.

Very helpful video. I have seen other DIY videos on this modification that have been posted which lay out the issue and good solutions. But your video advances the DIY technique with the high ceiling intake much like the one piece commercial upgrades. Very good addition to the DIY solution! Thank you!

Can get the same foam from lowe's 24" x 24" for $5 bucks each. 2 will do 2 AC's. I did this to my AC's 3 years ago. Increased air flow on my units by 60%. Big improvement.

1st mod I've watched not adding the bottom under the V. Probably a much better design so more return air gets in. Bet it helps the a/c run more efficient also!

I did your baffle box A/C mod on my previous Winnebago TT and that worked amazingly! I’ve since upgraded to a cougar fifth wheel and will have to give this mod a shot! Since we only have the one A/C this is probably going to help considerably!

I have looked at a few of these and I like your design better. I'll be doing this soon to my new 5th wheel.

You know. When I saw the intro to your video I was skeptical. Now that I have watched it all the way through I can say I’m impressed! Nice work sir!

Did this mod last year. Works great. Just remember to keep dump vents closed or put a filter on them. If not you will have unfiltered air pulled into plenium. I bought .96 cent AC replacement filter from Walmart and cut them down to fit dump vents.

Did basically the same thing to my units rv went from mid to upper 80's in the late afternoon to mid 70's, and it now uses the whole filter element instead of only a quarter of it, next modification is to convert the units to use better house type filters

Very Cool! I will investigate this for my 5th wheel. Thanks

did a similar upgrade on my 15k unit and it really helped!

Great idea they need to do all this with the factory so we shouldn't have to dink with it as much as we pay for these units!!!

With 2 AC units and common ducting throught the RV when one AC is running air if forced in reverse around the squirrel cage blower then through the air filter in the unit that's off. This dislodges dirt and dust that was on the filter. Could this explain why there is so much dust in your RV? The fix is to make flaps (one-way valves) so that air from the AC can enter the in cieling ducting unimpeded but preventing air in the cieling ducts from entering the AC unit.

Great video this one needs to go viral im doing this for sure thanks for the idea

Hey J.D., thanks for making this video. It is super easy to follow, and a super easy mod the way you've done this. I just finished doing this to our ac unit. I love all the content you make and put out for us. Thanks again! 🙌🏼

For me, this has been the most helpful video yet. I just happen to have a 4 x 8 sheet of foam (foil backed) and a roll of aluminum tape. The foam is only 3/4 thick, but I don't see why it won't work. Thanks for this vid.

Great DIY! I've looked at the preformed ones that you mentioned and they look really nice, but this sure does save a lot of money with a little effort. Very nice.

You dont even need to use styrofoam for this. Cardboard works pretty well too. Im glad you pointed out the foil tape job beneath the AC. The number of times a customer comes in complaining about poor airflow through the ducts and it turns out the manufacturer just did a HORRBILE job with the foil tape is stupid.

i love the expanse of the return air. seems like that would make cleaning the filters easier!! i plan on doing this on my trailer in the very near future.

Very nice! You explain things very well, good job. I will be doing this very soon, especially since I am moving to a RV Park where I will be paying for my electric. Can't believe that "Airflow Systems" company charge $170 for basically a piece of styrofoam. So thank you!

I would check the duct work too by taking off the vent cover and looking inside. I had two large voids that I was able to close off that was going nowhere and wasting air.

I like your design looks good. Great job on doing this one handed holding the camera while installing.

I agree.....AIR INTAKE MODIFICATION BUILD. It's got to breath, AND this way also allows no reduction of return air.

Wow, I've been watching many of these ac modifications and just finished mine. I ended up with the one that keeps the block in the middle all the way down. But after watching your install i see that this is the one i want to end up like. You did it just like that $170 kit you can buy and a whole lot cheaper. Great job you did there.

Most excellent & easy diy project. I’ll be doing it myself very soon. I think I can save myself the cost of the foam by just using all the packing materials that come in the boxes from stuff we order. All I need is a roll of tape and I’ll be good to go. A sincere thank you!

Wow, that is pretty neat. Hope you do a follow up in a few weeks after you have had some really hot days. Have you first timed how long it takes to cool down the trailer when first turned on to have a baseline to compare to?

Good video. I did something similar but nit channeling directly. I lined the inside with reflexive which greatly improved air flow output through the vents. Looks like I may need to go back and do an additional mod like yours. Thanks. Great idea

Plan on doing this on my Rockwood and like this method. You are the 2nd one I've seen doing it this way. Just need to figure out how to work around the cords inside.

Your system makes more sense with a larger air intake, pushes more volume out verses the other ac mods on RU-vid. It's a great heads up. Glad I watched your video before I started this project this up coming weekend. One exception, I bought foam board at Lowes 24" X 24" X 1" for about $7 each board, only needing one board per ac. Thanks for the engineering tips though. 👍

Gonna have to do this to ours. We’re only able to run one ac at deer camp. Think this will help a ton!

The return air gains make it totally worth it, should move more air and cool better.

Three inch wide mastic tape with high density foam board might work a little better and the tape will never let go. A 1" or 1.5" 4x8 blue high density foam board would be cheaper and should stay cleaner longer since it's not as porous. Good video.

Great project. The piece you removed and cut is ductboard You could have it used instead of stroyfoam.

Keep in mind when doing this to a Dometic, If any service is needed for warranty,Dometic places their info tag on the bottom of the ac, Coleman is on the lip of the base. Either or make sure you write down or get a picture of the mgf# serial# product# and sku#, Therefore if a warranty claim is needed or you need the acs info for whatever reason, You don't have to tear out all of your work. This is only needed for a Dometic ac because of the info tag placement. I'm an authorized service provider for Dometic and when I need info,I'd hate to rip all this hard work out, lol. Do not remove the info sticker tho especially if under warranty. Take a photo or write it down and you're set. When I replace AC'S, I always do this,Customers ask why and I tell them that showing them is easier than telling them. Once completed they're very happy I did it, 1..It's quieter and 2 because of the pressure duct system,The end ducts always blow harder and the air volume decreases as it gets closer to the center of the rv. When I'm finished, The air volume is far greater than originally and these AC' have about 17⁰-22⁰ separation from the filter air to the duct air, With this upgrade you'll see almost 2⁰-3⁰ colder air. I also recommend upgrading the filter due to the increase in air suction. Cut to fit filters work well and won't restrict the flow.

Nice! Should help a lot. I did similar with ducting tape only, lined the whole interior of the plenum, which in itself helped at least 30-40% also people should try to fix the wires back on the return side to keep air flow resistance to a minimum. One thing on top of the unit upgrade like this itself, is to do the vents as well. I have added silicone door bump stops at the centers of the vents stuck up to the top of the ducting, it helps direct the air down into the vents more and creates path to guide it. On top of that if you really want to get fully capability you can also take the vents off and wrap the ceiling layers where the vent sits into so no air can go between roof structure but only into vents and also in the ducting itself check for any gaps ect to make sure to tape up too. Want the least air resistances as possible. Our ambient to inside air delta is about 25-35degrees normally. Single roof top with portable ac ducted through roof top vent. 33ft class c. Nice tut! Similar package of the same type of setup you did is $200😮‍💨

Love these videos. Hacks to make things work better!!!!

I am waiting until this weekend to do this on my 398MBL. Sure enough you posted a video with the same plan. I want to increase the amount of return air as well ad your idea is perfect.

Was wondering if you were ever going to get to this type project. I agree on letting the bedroom stay stock and allow ac control to direct into bedroom only at nite. You need that adjustability in the hot Texas nites! Nice job. 😎🙃👊🏻

Great information as always. I’ll be doing this mod to my new Rockwood 2516s. Thanks JD

I have a dump model like that in the bedroom, so I might do what you did there. But the livingroom AC is a whisper quiet, so I have to hope they did a good job on that one.

So I have a 3414 Stryker ToyHauler 50amp with 2 AC units . I tried this mod and let it run for a few hrs . Since I have 2 Ac I didn’t notice A significant difference. So I decided to remove it , I noticed more Moisture on the cold air side . I don’t know if that would cause a issue long term . So I ended up just re-taping and properly sealing the poorly sealed factory installed on both of my units . I think just doing that made the system more efficient. I also scooped and taped the duct ports for better air flow thru out .

Good AC hack! If I ever get a trailer with ducted air I’ll do it

Of all the videos on this subject I really love your method 👍 thank you

So, what happens if you want it to come straight down into the coach? Do you lose that dump function?

I did almost the exact same modification on mine! Ours was soooo loud that we couldn't watch TV with it on. After the mod the sound was literally cut in half and the air flow almost doubled. I made a video on it but I am behind on my editing. It will be up on my channel in 2-3 weeks.

Someone needs to make a replacement cover with high capacity filter that can take advantage of the full return surface area.

Well done JD! Very impressed.

Looks better than my factory hack job on my forest river.

Get us some mods for the whisper quiet systems. That what I have and haven’t figured out what to do other than make sure the vents are all sealed up good. Actually the factory did a good job in that area on ours. Thanks

There was no way I was paying $150 for a block of foam so I did this exact same modification on mine. I did check before and after with an anemometer and the improved airflow was well worth it. And I also noticed the reduced noise level. And I also fixed the original taping which was done very sloppily.

Jd, could you give us an update on the overall performance of this mod now that summer is here and Texas is blazing hot?

Nice Oris Aquis.

Why not use a 4' x 8' sheet of foam insulation board? Less than $15 for a sheet.

Maybe could use a piece of paneling and tape total cost for 3 units around $25

My Grand Design came with the airflow system thankfully

Nice job JD should make a huge improvement

I shoulda done that I used the premade product he talked about RV AC Silencer. What I did notice though removing the original its shoddy craftsmanship at least the Dometic one. The construction is loose which makes noise. Then the air is sucked through tiny holes. So if your a computer gamer you want a power supply that is slotted. It much more aerodynamic and makes alot less noise. To add to the noise reduction I bought a sheet of Dynamat which is used in car audio to stop the vibration and noise. I cut that into strips and placed it all over. I can now sleep with my AC on in the bedroom just fine.

i did the same concept but used "foam core" bord same size as posterboard from my local dollar store......wayyyyyy cheaper than what you spent

Very nice. I like how you kept the area below the plenum open for better return air flow. You can also keep the air dumps open to draw more return air in.

They create a new “plenum”

I did a similar project it made my unit to create ice on my unit on outside

Very Cool...literally!

I'll have to try this.

Definitely doing this, the airflow to our master is horrible right now

I don’t have access to a/c from the inside. My question is can you remove the a/c unit from the roof and install it in the roof cavity.

I really like the looks of this modification, with the large return air. Did this make the ac units quieter? 😎🦅👍🇺🇸

New to the RV thing. Just got my first 5th wheel Mountaineer. The AC in this thing is awful. It has a Dometic unit. Will this mod work on it the same? Thanks in advance.

Makes me wonder why they don't just redesign the insert piece that was left out to do the same thing.

Also, if the leave the dump vents open, you will be sucking in unfiltered air. Maybe put filter material behind them.

That is awesome! Any suggestions to improve the whisper quiet system, considering its hidden in the ceiling?

Is there a concern that all that additional pressure blowing into the ducts will blow out the ducts? I mean, it’s not “stick and brick” construction. What’s your ducts made of? And did it hold up?

Would this mod affect the performance of a heat pump model? The heating side of the unit?