Improving the Coleman Mach A/C

[Rustynuts]

Originally Posted by StupendousMan

Any reason why you didn't make this a solid box? Was thinking about printing one but was going to design it as a solid box. Just don't want to go through all the hassle if you have already found it won't work

The first thought was it would have had to be in 2-3 pieces because of my bed size. Then once I got to measuring there was variance from side to side because of welds sticking out or sheet metal. I also didn’t want to unbolt the flange and break the seal if I didn’t have to and would not have been able to get a 1 piece unit in without removing the flange. Decided it would be easier to just print in pieces and tape in place.

[StupendousMan]

Right on! Thanks for the insight and the link to the print. All of that makes perfect sense!

[JesseS]

As I don't have access to a 3-D printer I opted to purchase the kit, with the Changing Lanes discount code. On my Alante the rear ducts especially had weak airflow, and with the air shower open had almost none. The only modification I had to make was to cut 1" of the duct insert flange as they were wider than the duct opening, height was fine. The air outlet matched up with the inlet on the foam block insert fine so I did not have to adjust the AC unit. Everything went in great after the dremel work on the inserts.

Air speed increase as measured with a HoldPeak Pro Anemometer ran from an average of 5.2mph in the front (near the AC unit) to 5.5mph in the back bedroom, which was great. Max airflow was 11.4 and min 8.2, with an overall average of 9.3mph. The unit is definitely moving a lot more air than the OEM configuration did. Be interesting to see how much better it works in Winterhaven this spring. I also did an airflow mod on the evaporator cap to increase heat dissipation.

[Route 66 Traveler]

Well, that's encouraging. My A/C is now pretty efficient after I plugged up all the duct leaks and sealed the separator, but I still plan on installing that kit when I get the chance. Good to hear the discount code still works. Thanks for the report.

[lselinger]

I'm just curious if anyone has tried or looked into attempting this mod on the Airxcel Colman Mach set up with the "quiet" installation? I have a regular Coleman Mach in my back bedroom and the quiet ac unit for the front (I have a 2014 Jayco Pinnacle 38 FLFS). The main unit is a 15,000-BTU low-profile Whisper Quiet A/C with no access in the coach like the back one but it certainly seems to struggle even keeping the unit the same as the ambient temps once the sun is blazing. The air coming out of the vents is certainly cold but there's just not enough velocity or volume to get the coach cooled off. It's an open plenum so both ac units can feed the whole coach so I'm thinking of at least doing the back one but before I commit to taking off the " quiet" one to have a look inside the plenum/duct I was wondering if anyone else may have tried this already.

[MDC]

I had the same question earlier in the thread but never received any comments

[Route 66 Traveler]

I just posted this in another AC Thread in case you missed it. Installing the RV Airflow is the best AC improvement I have made to my RV.
https://www.jaycoowners.com/forums/f...tml#post988369


"I have a 30' travel trailer with one 15k Coleman Mach AC. It has 5 ceiling ducts, 3 in the living area, 1 in the bathroom and only 1 in the bedroom. Being that I live in Arizona and frequently go RV'ing in the summer heat I was a bit dismayed at the performance of my AC and was seriously thinking of adding a second AC.

When I first saw the RV Airflow on a couple of other web sites I was at first pretty skeptical about the reviews, thinking it couldn't possibly do much more than I had all ready done to my AC, such as sealing up all of the ceiling air leaks, fixing the foam separator in the AC itself that keeps the hot and cold air from mixing.

After watching the video in Post 13 I decided to bite the bullet and order one using the 15% discount. Before installing it I went out to my trailer and using my hand held wind meter measured the airflow coming out of all of my ceiling ducts. The meter showed a wind speed between 8 & 9.5 MPH.

The installation of the RV Airflow took me about 45 minutes. One of the supplied plastic duct inserts was a tad too long...or my factory duct was a bit too narrow..so I had to trim it to fit which was no big deal. On my first attempt to slide it into place it got stuck. I was afraid to force it into place so I removed it. I got a solution of dish washing soap and water and coated the foam as well as the duct inserts with the liquid. On the second try it slid easily into place, lining up perfectly with the duct inserts.

After I put everything back together I turned on the AC and was immediately impressed. The air was blowing so hard it blew the instruction sheet off the table! I then took the same wind meter and measured the wind speed as I had done previous to the install. On all ceiling ducts the wind speed showed between 18 and 20 MPH! I frankly couldn't believe it!

Now the trailer cools down much faster, the AC doesn't runs as long between cycles, and my wife has actually complained that "It's too cold!"

It has been one of the best mods I have ever made to my trailer, the second best being the installation of the SoftStart module in the AC unit itself. It has saved me from having to add a second AC to my trailer, saving me some big bucks. It was worth every penny to me".....

[lselinger]

Well for posterity I did my own mod to the bedroom AC unit but I haven't even looked at the "whisper quiet one" with no internal access cover inside the rig.

In case anyone is interested I'm including the images of my custom mod. It certainly improved the flow but with an open plenum between units, by the time it gets to the front most vents although better, it's still weak. I'm hoping I can figure something out for the other unit as it doesn't seem anyone else may have tried this kind of improvement. If they make a kit I might be more interested instead of doing custom work again but every time I tried to email them it bounced because I used a gmail account (?)

https://photos.app.goo.gl/AB9qp7RCHRtQHmfY8

[pconroy]

Originally Posted by StupendousMan

Right on! Thanks for the insight and the link to the print. All of that makes perfect sense!

Also - my installation was plagued with corners not perfectly square. With his 3 piece setup, I was able to shave a little bit off here and there and adjust the fit.

[Big1]

Originally Posted by Route 66 Traveler

I just posted this in another AC Thread in case you missed it. Installing the RV Airflow is the best AC improvement I have made to my RV.
https://www.jaycoowners.com/forums/f...tml#post988369


"I have a 30' travel trailer with one 15k Coleman Mach AC. It has 5 ceiling ducts, 3 in the living area, 1 in the bathroom and only 1 in the bedroom. Being that I live in Arizona and frequently go RV'ing in the summer heat I was a bit dismayed at the performance of my AC and was seriously thinking of adding a second AC.

When I first saw the RV Airflow on a couple of other web sites I was at first pretty skeptical about the reviews, thinking it couldn't possibly do much more than I had all ready done to my AC, such as sealing up all of the ceiling air leaks, fixing the foam separator in the AC itself that keeps the hot and cold air from mixing.

After watching the video in Post 13 I decided to bite the bullet and order one using the 15% discount. Before installing it I went out to my trailer and using my hand held wind meter measured the airflow coming out of all of my ceiling ducts. The meter showed a wind speed between 8 & 9.5 MPH.

The installation of the RV Airflow took me about 45 minutes. One of the supplied plastic duct inserts was a tad too long...or my factory duct was a bit too narrow..so I had to trim it to fit which was no big deal. On my first attempt to slide it into place it got stuck. I was afraid to force it into place so I removed it. I got a solution of dish washing soap and water and coated the foam as well as the duct inserts with the liquid. On the second try it slid easily into place, lining up perfectly with the duct inserts.

After I put everything back together I turned on the AC and was immediately impressed. The air was blowing so hard it blew the instruction sheet off the table! I then took the same wind meter and measured the wind speed as I had done previous to the install. On all ceiling ducts the wind speed showed between 18 and 20 MPH! I frankly couldn't believe it!

Now the trailer cools down much faster, the AC doesn't runs as long between cycles, and my wife has actually complained that "It's too cold!"

It has been one of the best mods I have ever made to my trailer, the second best being the installation of the SoftStart module in the AC unit itself. It has saved me from having to add a second AC to my trailer, saving me some big bucks. It was worth every penny to me".....

You wouldn't happen to have any pics do you?

[Route 66 Traveler]

Of what, my wind meter? If you don't believe me here is a quote from another Forum member who came over to my house yesterday and witnessed the readings I took for him, posted in the Class C section:

Originally Posted by Forelyndogs

Since I live in the same town in Arizona as Route 66 Traveler he invited me to see the results of his installation of the RV AirFlow device. I was shocked when I stepped into his rig parked next to his house in the sun. The volume of air coming out of all of his a/c vents is vastly greater than what comes out of my vents. He has the proof too. He measured the airflow before the gadget at between 8-10 MPH and he is now getting 17-19 MPH. He is using a standard airflow gauge and holding up to the vents. The coach was cool and comfortable and I am inclined to agree with his wife's observation that with that airflow it would quickly get too cold. How often does an RV in the dry hot west in summer get that cool? I am definitely going to pursue getting the RV AirFlow device.

[Johnynorthland]

Does anyone have temp readings, before and after?

[pconroy]

Originally Posted by Johnynorthland

Does anyone have temp readings, before and after?

Temperature readings? I think that's thinking about this wrong - the AC doesn't blow >>colder<<.

What happened in my coach is that the modification just blew ****more**** of the cold air around the coach.

In other words, the mod does NOT make the air coming out of the AC "40 degrees below ambient". No - the air is still about 20 degrees less than ambient.


If it's 100*F outside, the air coming from the AC was still around 78* to 80*F.

What the mod did for me was push more of that "78-80*F" air around the coach. The coach hit 78-80*F **faster**.

[Route 66 Traveler]

Originally Posted by pconroy

Temperature readings? I think that's thinking about this wrong - the AC doesn't blow >>colder<<.

In other words, the mod does NOT make the air coming out of the AC "40 degrees below ambient". No - the air is still about 20 degrees less than ambient.

If it's 100*F outside, the air coming from the AC was still around 78* to 80*F.


What the mod did for me was push more of that "78-80*F" air around the coach. The coach hit 78-80*F **faster**.

Not trying to argue your statement, just state what I have observed in my trailer since the install. While camping in Las Vegas on July 9 & 10th they set a record of 117 degrees, my trailer was averaging 80 degrees inside, even showed 78 at one point, parked in the sun with no shade.

Yesterday while demonstrating it to "Forelyndogs" (see post #31) using my wind speed meter that also shows wind temperature, it showed a wind speed out of the ceiling ducts at 19.4 MPH with a temperature of 57 degrees. The outside temp was around 87 if I remember correctly.

Regardless of the wind speed or temperature our RV is now much more usable in the summer heat of Arizona.

[pconroy]

Originally Posted by Route 66 Traveler

Not trying to argue your statement, just state what I have observed in my trailer since the install.

Understood - I stole that 78-80 from you. Just trying to make the point that taking temperature readings before and after would depend on a lot of things - outside of the mod.



Did it make our coach cooler?

Yes.

[Route 66 Traveler]

Was it worth the money? Yes, it saved me from the expense of adding a second AC....

[Johnynorthland]

Correct me if I’m wrong but doesn’t it turn the air dump into a return? If so I would think you would have an efficiency of Colder air.

[Route 66 Traveler]

That’s probably true, I’ll have to check, but doing that would bypass the air filters. I have noticed that there is a great increase in the amount of air going through the filters and this requires more frequent cleaning.

[pconroy]

Originally Posted by Johnynorthland

Correct me if I’m wrong but doesn’t it turn the air dump into a return? If so I would think you would have an efficiency of Colder air.

That's a good point that I didn't consider!

[Mikec557]

Originally Posted by pconroy

Temperature readings? I think that's thinking about this wrong - the AC doesn't blow >>colder<<.

What happened in my coach is that the modification just blew ****more**** of the cold air around the coach.

In other words, the mod does NOT make the air coming out of the AC "40 degrees below ambient". No - the air is still about 20 degrees less than ambient.


If it's 100*F outside, the air coming from the AC was still around 78* to 80*F.

What the mod did for me was push more of that "78-80*F" air around the coach. The coach hit 78-80*F **faster**.

I think your explanation is great. But there is one place I would change the wording.

Where you say the AC will blow 20 degrees "lower than ambient", it may make the reader think you're referring to the outside (of the camper) temperature. What counts is the air temp inside the camper.

The AC, in general, will/should, blow air about 20 degrees cooler than the air it sucked in. That's the air temp inside the camper. So if the camper is 100 degrees inside, the AC would blow 80. As the inside cools, the intake air temp will be colder. When inside air temp reduces to 90degs the AC will blow 70, etc.