DIY AC duct efficiency improvement project?

[JohnnyPop]

Basically pull straight down. Feels like you’re going to break it but it pops off with a snap.

[ependydad]

Originally Posted by doc73

While I did not read everything word for word here but I was recently looking at the ac styrofoam thing for the $200 and a YouTube channel I follow just so happen to get one to try. He had already sealed the vents better,the return and sealed the dump valve with foil tape and reflectix. He got a little gain by adding the wedge thing but not nearly what was claimed. What he found was by just sealing the vent, divider, output and return did okay but by selling the dump valve is what made the most difference. He found that while the foam thing does work really by just diy sealing the dump valve does 90% what the 200$ kit did.

So just covering the dump valves with HVAC tape?

[doc73]

Originally Posted by ependydad

So just covering the dump valves with HVAC tape?

Exactly. He did say while the $200 thing did help divert the air a bit most of the help actually just came from blocking the dump which didn't require the 200 thing.

[ependydad]

Originally Posted by doc73

Exactly. He didn't ayt while the $200 thing did help divert the air a bit most of the help actually just came from blocking the dump which didn't require the 200 thing.

Guess I know what project I'm doing next! Maybe it'll stop the whistling, too.

[Kcoulter]

Originally Posted by chriscowles

On the topic of duct ends, how do I remove the cover without breaking it? Unrelated to this project, I broke a vane in one when I hit it with something. Now it won't stay open. I can swap it with the one in the bathroom because we usually keep that one closed. But I don't want to break the good one taking it out.

Very carefully...and little fingers help.

In that photo above you can see the tabs that need to be pulled in to release the cover. Same tabs on opposite side, too.

My big hands usually end up breaking one of the vanes taking it out. A new one is only $8
https://www.amazon.com/gp/product/B082FYRYBH

[Chuck_S]

Just "sliced" one of the 3D upper fillers. 21.5 hours to print just that one. Hand carved Styrofoam seems much simpler. It's all gonna hide under tape anyway.

-- Chuck

[GPs37FLH]

I installed the RV Airflow system in both of our Coleman Mach 15's earlier this year. I also removed most of the duct taping done by the factory as it was less than sub-par.

Once I re-taped everything solid and added the RV Airflow system, it was night and day difference in our RV. We're getting twice the air flow thru our ducts than it was before and no more whistling or rattling noises either. We now keep both thermostats on Cool Low and it keeps us comfortably cold, even in 90+ degree, high humidity conditions. For us, it was well worth the dollars spent.

I watched many of the YouTube videos on the DIY method. But, my time is worth a lot to me (more than the cost savings of the DIY method) and buying the product was a big time saver for me. Its also so much easier and quicker to remove and remount the one whole component should I need to access that area, or replace one of the AC units in the future.

[JohnnyPop]

What about noise reduction with the RV-Airflow?

[GPs37FLH]

Originally Posted by JohnnyPop

What about noise reduction with the RV-Airflow?

Before I installed RV Airflow, we had annoying rattling (buzzing) and whistling sounds in both our AC units. We had to rig a piece of cardboard and jimmy it into the AC dumps on the one above our living room to dampen the rattling, but you could still hear it. After installing RV Airflow, both AC's are whisper quiet.

[Chascin]

After installing the RV Airflow we noticed higher flow but most of all did not have to have the volume up on the tv to watch and be able to hear what was going on.

[dankirk]

I installed the RV Airflow in our Rockwood Windjammer today. Make sure to order the Shallow Plenum model to fit our Rockwood/Flagstaff trailers.

Install was easy. I had to trim some of the factory spray foam, and I used foil tape to clean up the openings from the plenum area into the ducts. It is significantly quieter and a lot more air flows from the vents.

I used a 15% off code from a youtube video, and it was about $170 with shipping. I'm happy with it.

I'll post pics later.

[dankirk]

Originally Posted by dankirk

I'll post pics later.

Here are pics. You can see the plenum area from the factory. Then after cleaning up with foil tape. Then with the duct inserts installed, and with the RV Airflow installed. I imagine that making something with foam board would have about the same result, but it was worth it for me to just buy the part.

[lwbfl]

I've done the DIY thing on a few that I fixed up for others but found that it really depends on how well the factory / dealer completed the work. If you have a lot of air leaks, it really helps with flow -BUT simply using metal repair tape to close off the gaps may be just as effective. The noise reduction comes from blocking the air from blowing directly on the inside cover. Open the "quick cool" vent and you'll see how much noise this makes! The better insulated the product blocking this noise (or redirecting it into the ducts) the more effective it will be. I do use mine so this is not an option for me. I inspected my current unit, it is well sealed so I didn't have to do anything to it. My trail-bay was horrible though, and the tape around the ducts really helped!

[cobia]

It works good, not hard to do. Took me about 1 1/2 hrs to complete. Material at lowes was less tha 15 bucks. Look on YouTube to see how it's done. You want believe how many air leaks and blockages you find when you get in there.

[RobinDella]

Originally Posted by chriscowles

Has anyone done the AC duct efficiency improvement projects described in a number of YouTube videos? They're copying the RV Airflow idea, building it out of duct board rather than paying for the custom-molded styrofoam. If you have done it yourself, was there an improvement?

I looked in the plenum of the 15K BTU Coleman Mach AC in my Mini-Lite. It looks to me like Rockwood did a pretty good job of isolating the return air flow from the cold air output, and sealing the obvious big gaps in the output plenum.

What I don't know is whether adding the baffles to the outflow improves the efficiency of pushing the air down the ducts. Even if it does, it's not worth the cost to me of paying RV Airflow for their kit. It would be cheap for me to do it myself using 1/2" insulation sheathing and the project would be interesting, but I don't want to waste my time if it doesn't accomplish anything.

The insulation board insert would block the air dump outlets, but I really never use those.

Oh hell yeah I did it spring last year works absolutely fabulous. I spent like 10 bucks

[RobinDella]

More to it than just covering the dump. Check you tube there’s several videos on it. Did ours last spring for teen bucks. Works great

[larry2c]

Originally Posted by chriscowles

How do I find somebody with a 3D printer? It's definitely not something I'm going to buy myself. Is there a network of people who do that commercially?

Maybe somebody has already suggested this but a lot of local libraries have 3D printers now. Since there is no "load" on the components, any polymer material will likely be fine for the printed parts. Just my 2¢

[DennisTD]

I just did the DYI version in my XLR Hyperlite with Dometic 15K. It certainly cools much better (no quantitative data) and, just as important, it is much quieter. I also bit the bullet a couple of months ago and installed a Micro Air Easy Touch thermostat. Quite expensive, but worth every penny. No more short-cycling...we can actually get a good nights sleep!

[RetiredSoldier919]

Originally Posted by larry2c

Maybe somebody has already suggested this but a lot of local libraries have 3D printers now. Since there is no "load" on the components, any polymer material will likely be fine for the printed parts. Just my 2¢

You might want to download the stl file from Thingiverse and then check it for print time. You can use an online gcode analyzer like this one http://gcode.ws/
to check for material used and print time. The library is not likely to allow you to run a 12 hour print job.

[csterl01]

From what I have read, the purpose of the kit is to smooth out airflow as well as eliminating leaks and cross flow. The air coming out of the unit deadheads onto the dump grill or bottom of the duct, creating turbulence which reduces flow. Smoothing out the flow by installing a triangular shaped piece below the discharge should help increase airflow. I bought an aero manometer to check airflow before and after mods on my vents, but haven't worked on it yet. Also gaps behind the grills is allowing conditioned air into the ceiling, as I have cool air coming out of the hole when I removed a light. I have a lot to do on mine but, in the meantime, I'm having a third unit installed this week