RV AirFlow Systems Install

[EA37TS]

This morning I installed the RV Airflow System in the living area AC unit.

First I disassembled the unit and started taping all noticeable gaps. Most of the gaps were ones I created looking around inside. I had to trim the duct inserts which is a known issue and addressed in the instructions. To finish I installed some new charcoal fiber filters along with the screen style filter. I believe airflow is better but there does not appear to be the advertised noise reduction.

[EA37TS]

After 30 minutes of the AC running the air temp going into the ac cold air return is 63.8 and air coming out of the duct is 36.3 which is a delta T of 27.5 degrees. The outside temp is 84 degrees at 9:36 am.

[Judge]

I installed the RV Airflow in one of the two A/C units last year.

The fit was not as good as I felt it should have been but their customer service was great. They made some minor changes after sending them some pictures and videos. They sent me the changes in a few days and it fit much better.

There is a noticeable increase in airflow from the ceiling vents now that the unit dump vents are completely sealed off. But I agree it is only marginal quieter at best.

I installed mine in the front A/C unit so that it would increase airflow throughout the coach so at night I would not have the noise of the bedroom A/C running right above us.

It worked as planned..... both units run during the day but even on the hottest days / nights we can get buy with just the front A/C unit running at night to keep the coach cool enough now.

This was the final upgrade I did to my A/C after insulating the evaporator enclosures on the roof and improving the ceiling ducts. I think the RV AirFlow was worth it for one A/C unit but I can't see the need to add one to the second A/C.

[BlueE450]

Been using RV Air for about one year and very pleased with the improvements that we realized. Great buy.

[Wrpt58]

I installed the RV airflow on the only AC unit on it. I really like the difference. I've been in Central Louisiana since 6/15, in the unseasonal heat. It performed well, keeping the RV at 75 - 82 all the time. I got used to the noise.

However, when I installed the RV Airflow, I also went on top, insulated the evap. line, which had been un-insulated (probably deteriorate off). I also reworked the cover on top by installing plaster lattice wire over the condenser air flow areas and cut out the plastic "fingers" of the cover.

I believe the upper mods help as much as the RV Airflow.

[Judge]

Originally Posted by Wrpt58

I installed the RV airflow on the only AC unit on it. I really like the difference. I've been in Central Louisiana since 6/15, in the unseasonal heat. It performed well, keeping the RV at 75 - 82 all the time. I got used to the noise.

However, when I installed the RV Airflow, I also went on top, insulated the evap. line, which had been un-insulated (probably deteriorate off). I also reworked the cover on top by installing plaster lattice wire over the condenser air flow areas and cut out the plastic "fingers" of the cover.

I believe the upper mods help as much as the RV Airflow.

I like what you did with the shroud. I have seen test results by people who did something similar and it makes a difference.

Don’t forget to insulate the evaporator enclosure and not just the line. I used Frost King adhesive backed duct insulation for mine and it does help as well.

[LarryD]

Originally Posted by Judge

I like what you did with the shroud. I have seen test results by people who did something similar and it makes a difference.

Don’t forget to i[B]nsulate the evaporator enclosure[/B] and not just the line. I used Frost King adhesive backed duct insulation for mine and it does help as well.

Judge, did you do a write up on this or the vent improvements you made?

[Cwray]

I don’t have a write up, but I did an additional couple of things that, imho, were each equally as effective as doing the airflow work. Admittedly, I followed some YouTube videos to create my own airflow solution. But nonetheless, we went from having our AC’s straining to keep our rig in the mid-high 80’s during a July 100+ set of days in full sun—to being able to getting it to 75-ish during the day. While that doesn’t sound like a big improvement, it’s the difference from experiencing sweating while sitting inside versus having a nice cool slap-in-the-face every time you open the door from the outside.

The two other things were insulating the shroud of our condensers, and camera-scoping and sealing our AC vents.

The insulation effort was a result of over buying the amount of insulation for the dog house. I found there was room to put both the 1/4” tar paper along with the 3/4” foam insulation around the condenser steel parts. The plastic cowling can just tightly slide over it. This gives both a sound as well as an efficiency improvement.

The biggest bang-for-my buck was buying the cheap $19.99 frog camera (or whatever it was called) in the as-seen-on-tv section in Menards and using that camera scope to take a peek inside each AC vent.

Admittedly, your mileage will vary. But for me—every section of styrofoam tubing in the AC ducts had big breaks between them. Also, the last vents in the run just emptied out into the ceiling space.

I bought a bunch of latex spray foam cans, a box of hand towels, and some straws. Jamming the straws together and then putting them on the end of the straw on the can of spray foam allowed me to effectively shoot that stuff three feet down the duct. I stuck my arm down there, and smushed the spray foam down in those 1/2” gaps and smoothed it out around the entire seam. For the end runs, I simply sprayed a wall-pile right behind the last vent.

It was messy, I felt stupid and childish, and also embarrassed for obsessive behavior in doing something no one else that I know of did. All in the quest to make the few times we’re using this RV more comfortable during the day. But I sh_t you not—it was easily in the “Top 5” mods that I’ve done to this rig. My wife giggled when she felt how cold I could get this thing.

TL;DR summary of best improvements for us in the realm of AC cooling:
3–putting insulation around the condensers
2–doing the AC airflow mod (the YouTube version)
1–scoping and sealing the AC ductwork.

These three things let us park in an asphalt parking lot in the middle of a full-sun July 100+ day, and keep our rig at a nice 75 degrees inside.

[Judge]

Originally Posted by LarryD

Judge, did you do a write up on this or the vent improvements you made?

I can't remember if I did a write-up.... I may not have since there are so many A/C threads. Here it is in a nutshell.....

1. Evaporator Enclosure on Roof - I removed the shrouds of the two A/C units and used Frost King Self-Adhesive Insulation to cover and insulate the entire evaporator enclosure (see the black arrow on the attached picture pointing out the enclosure).

2) I used a small piece of foam pipe insulation to insulate the pipe the runs from the compressor into the evaporator enclosure.

3) A/C Vents - I removed the covers over the A/C vents and used a very small saw blade to cut and smooth the styrofoam insulation in the ceiling for better airflow out the vents. Instead of using actual metal ducts, they just created channels in the styrofoam in the ceiling and then butchered holes for the vents.

On the last two vents at the front cap and the last two vents of the rear cap, I used spray foam to seal up the ends of the channels so the air didn't blow into the front and rear ceiling at the caps where it had nowhere to exit.

4) RV AirFlow - I installed the RV Airflow in the front A/C only so at night I could just run the front A/C and it would push more air to the bedroom.

5) WeatherTech Windshield Full Kit - The first thing I did day one was purchased the WeatherTech Full Cab Kit to cover the windshield and two door windows so the cab would not heat up.

6) We close the curtain over the cab-over bunk to keep the heat that generate in the front cap from coming into the coach. I also never open the cab-over window cover.

7) We keep all the window shade down as soon as the sun starts getting hot.


I have been in full sun with the temps in mid-90's and high humidity and never had an issue keeping the coach in the low to mid 70's.

However, you need to use a digital thermometer to measure the actual temperature in the middle of the coach to know how your system is really working.

The two temperature sensors are under the cabinets against the walls where heat radiates. The thermostat may say 82 but the actual air temp in the middle of the coach is really closer to 72.

Last August in Nashville it was 95 and humid. The Firefly thermostat was saying it was 85 inside. It felt like a meat locker to me. When I say my digital thermometer on the kitchen counter it was 69 degrees!

[LarryD]

excellent! thank you as always Judge, you are an invaluable resource for this board. We are so fortunate to have people like you, I just moved from NY to Fl (got here two days ago) and this will be essential to me. Thanks again!

[Judge]

Originally Posted by LarryD

excellent! thank you as always Judge, you are an invaluable resource for this board. We are so fortunate to have people like you, I just moved from NY to Fl (got here two days ago) and this will be essential to me. Thanks again!

You are welcome!

And keep the shopvac nearby when you pull the vent covers from the ceiling. There are a small styrofoam pieces up there and you will create a lot more when you start trimming and smoothing the styrofoam.

Since I did mine, I stopped getting the little styrofoam balls flying around the coach when running the A/C.

[HillCountryGuy]

I have the rvairflow installed in our travel trailer and was pretty happy. However when we installed on in our coach, we were less thrilled than we had hoped.

The concept is good, but I felt there was a much simpler solution that would also allow us to keep the dump vents. Looking at the Dometic return grills, we knew the solution. It is documented here with the results.

https://www.thorforums.com/forums/f2...ent-31750.html