2023 3123RL Legacy AC Airflow - serious issue

[fatcatzzz]

I have the impression they want me to go away.
Quite disappointing.

I am afraid you might be correct. I do not have 2023, but my third AC is direct dump. Also I have never heard of a H-frame system. I have been in several Montana fifth wheel and all have had direct dump AC for their third AC.

This is one of the reasons I am looking to purchase SOB in September. Keystone has lost all creditability with me.

Good luck with your problem.

 

[Ozzie66]

Bourbon Country, please tell us what your "$100 fix" is that you mentioned on your other post from a year ago about "AC Issues" Thanks. Ozzie

 

[Carl n Susan]

Bourbon Country, please tell us what your "$100 fix" is that you mentioned on your other post from a year ago about "AC Issues" Thanks. Ozzie

I suspect you are referring to "Bourbon County" not Country. Do you have the link to this year old Post?

 

[Bourbon County]

I don't guarantee this to be an absolute fix, but will be of great improvement. For transparency, I have training and a now expired certificate in air balancing; as well as tools to measure air flow.

The key to any forced air AC system, home or RV, air distribution is the secret sauce. The less restrictive the duct system, both supply and return is, the better the airflow. Basically all I did was to buy one of most every different vent on the market and did some measured testing. I determined the Valterra A10-3359VP to be the least restrictive. They are 5.5 inches ID as opposed to the 5.0 inch from the OEM so I did have to do some cutting. Believe it or not, just that extra half inch gives an additional 20% bigger opening. The larger opening combined with much less restrictive blades was ideal to me. I replaced all vents in the trailer except bathroom with them.

In the bathroom, I chose the Valterra A10-3354VP which is an adjustable model. When adjusted all the way up, it still allows some airflow. There is a very recent thread where folks talked about completely or largely taping closed the bath vent. When you think about it, that's the smallest room in the RV and in the models that have the bath at top of stairs, it's in the area of the racetrack duct with highest air pressure. With possibly the exception of shaving, the only times the room will be occupied longer than a few seconds the big exhaust fan will be running. It's smallest room with lowest occupancy, no need to pump so much air in there.

Next area: returns. I found the ceiling board not completely cut out under the frame for the filter element. Trace out the inner opening of the trim ring and cut out the ceiling board. With all the cut outs you make, tape up with the foil type duct tape. Dispose of the dorky foam filters from the factory. I'll link some I found on Amazon that will have to be cut to fit with scissors. It's a horse hair type filter made of polyester. I even run mine through the washer on low cycle. They are a MERV6 rating which is very low restriction. If you feel like you need air filtration, buy a floor standing HEPA model.

https://www.amazon.com/FilterTime-A...-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

Once this is done, you can start doing some crude balancing. In addition to the bathroom, the other vents that fall near midway between the 2 units along the racetrack duct will be the ones you can close partially. When pointing the louvers be cautious not to point them directly toward a return. That's called an air short circuit because it's mostly just being pulled right back into the return. I found the ones closest to rear of RV worked better pointing to the rear.

This will be mostly trial and error; if you do want to be more scientific about it, there are some anemometers on Amazon in the $30 range that will work fine. I'll be glad to link them as well as instructions to make a capture hood if you're interested.

I documented and charted all my readings and will post if I can find them. I did get a 28% increase in total air flow, and putting in the right place makes a huge difference. I did find that leaving both units with blowers on manual high worked better over time.

 

[Ozzie66]

I suspect you are referring to "Bourbon County" not Country. Do you have the link to this year old Post?

Carl n Susan, thanks. I found the Bourbon County post by my MOC search: general
discussions/about our Montanas/Air Conditioning Issues: Here it is:
06-28-2023, 01:52 PM #14
Bourbon County
Montana Fan

Join Date: Feb 2022
Location: Cynthiana
Posts: 234
M.O.C. #30449
Did you have an opportunity to measure temps to see if your AC units are working properly? If you did, could you post your readings?

You mentioned the vents closest to the unit were getting less airflow. In my experience with the Keystone racetrack duct, you have 2 different units on opposite ends of the coach blowing into common ducts. If both units are running or if the blowers are running in manual, the airstreams just but heads in the middle of the duct. This configuration puts the highest concentration of air pressure near the middle of the coach, which is where you probably need it the least. They tend to deliver the least air at either end of the RV.

I realize your camper is brand new and as long as the ACs are running, they won't do anything under warranty. Keystone isn't going to pay someone to replace their patented blade diffusors. There is a way to correct this for about $100. I did this to mine and improved airflow by >30% and more importantly, put more cooling in the rear of the coach. I'll be glad to share if you're interested.

 

[Ozzie66]

Bourbon County, thank you very, very much for all the info on how to improve our AC system. I hope that I can call on your expertise when I get into doing the system improvements.
Ozzie

 

[Bourbon County]

Bourbon County, thank you very, very much for all the info on how to improve our AC system. I hope that I can call on your expertise when I get into doing the system improvements.
Ozzie

Thanks for the call out. I will be glad to offer whatever assistance I can be.

I see you have a new model; if it has the H-frame duct system that's been discussed, it might be a little different. Larger and less restrictive vents and less restrictive return filters are never a wrong move. Your balancing might work out a little different. The way I see it, the turbulence in the H-frame duct system will be at the ends of the ducts rather between the 2 units like it is with the racetrack.

It might be worth buying an anemometer and measuring to see where most of the air is going before trying to do any adjustments.

 

[loadmaster-MOC]

Coleman-Mach ductwork blocked

Could it be possible that both sides of the common racetrack ducts have a Tee at the position a third AC could connect to the duct system when installed? Imagine looking down on it, it would look like an H. Is it possible that the plywood blocks you photographed are blocks for the ends of these sections of ducting?

I can't imagine how inefficient adding a third unit to a ducted system would actually be able effective at all. You're adding an additional 350 CFM of air flow to already undersized ducts, you're adding it near the center of the trunk lines which would only generate more turbulence. If this theory is correct, having sections Tee connected to the trunk lines and capped off, you are still pressurizing that section and getting absolutely no good from it. This looks like a lose/lose situation.

Did you ever confirm if you were or were not getting airflow throughout the coach with only unit running? Even if you can't feel it with your hand, try putting a couple of squares of CLEAN toilet tissue against the vent. It's very light and takes very little air flow to move it.

No sir, had the mobile service tech from Camping World take down the vent fan in the kitchen and looked in the ceiling and no way to attach a third AC unit to the duct work.

I'm working with Keystone to found out why they put the blocked wood in the duct work.
Thanks for the information
James

 

[loadmaster-MOC]

Coleman-Mach ductwork blocked

I am afraid you might be correct. I do not have 2023, but my third AC is direct dump. Also I have never heard of a H-frame system. I have been in several Montana fifth wheel and all have had direct dump AC for their third AC.

This is one of the reasons I am looking to purchase SOB in September. Keystone has lost all creditability with me.

Good luck with your problem.

If I would have known this I would not have bought the unit, because my old unit a Montana 3582RL did not have any problems cooling the unit down.

 

[loadmaster-MOC]

I would like to thank everyone for the information, at this time I working with Keystone to find out why, they blocked the duct work. If I get and answer I will post it for everyone.

But again I'm just getting started finding out information about different things on this camper.
Thanks
James Blackford

 

[foldbak]

Somewhere on Keystones website it say that the 3rd AC is direct dump.

 

[loadmaster-MOC]

Keystone Service Team/Coleman-Mach AC units/Ductwork

No sir, had the mobile service tech from Camping World take down the vent fan in the kitchen and looked in the ceiling and no way to attach a third AC unit to the duct work.

I'm working with Keystone to found out why they put the blocked wood in the duct work.
Thanks for the information
James

After sending Keystone pictures of the blocked ductwork, I received a reply back and this is what I was send.


"Our service team is not able to make out much from the photos. I would advise taking it to the dealer and having them inspect. If they find a defect they can submit it to Keystone under warranty."


I have been thinking about this for a while, since the rear AC unit is a air conditioning/heat pump, I guess running the heat pump the unit would not be able to keep the whole unit warm in the cold weather, this is why the ductwork was blocked off to keep the living area warm, so that is why I was told to run the fireplace and the furnace to keep the unit warm.
But the problem is the airflow doesn't get to the thermostat to tell the unit what the temperature is, sense the airflow stops at the third set of outlet in the ceiling.



Then my thoughts are why did you put something in that will not keep the unit warm, just use the furnace and fireplace, or install a heat pump in the bedroom to solve the problem.



This is the start of things I need looked at, the Refrigerator does it have a drain on it, because my old one did drain into a pan in the back of it. It was and Electric/Gas unit, the good one. I came back from Myrtle Beach and shut the unit down, after a day I thought I would check it out to see if the unit had defrosted and make sure enough everything was OK and, here is all the water laying in the bottom of the fridge and just about to run out on the floor, so want would the company do if the floor over time rotted out due to the water from the refrigerator leaking onto the floor. I guess I would out of LUCK and have to pay to have it repaired out of my pocket.Then why put a residential in a camper that if you had to replace it you have to take to slide out, boy that will cost you out your a** to have that done. Just make to door way bigger that way your can take to doors off and then remove the unit thru the door. I guess the would be hard because someone would have to design a bigger door.


Right now I would love to have my old unit back because I think this is going to be a big dam headache working with Keystone to get something done right. Plus I don't need my unit sitting in the dealer lot for months on end, if so I will unload it and let the loan company come get it.


My plans were to start traveling and see this great county, after serving in the military for 34 years and see it from the air, it time to see it from the ground, and not having to wait on my unit to be repaired.

Plus the quality of workmanship has gone down hill big time, I think it just as bad now as it was back during Covid. You would think paying that kind of money for a luxury camper you would get good quality workmanship.


Yes I know I'm running off at the mouth, but Keystone need to step up to the plate and work with US the customer to resolve the problem and to help make the unit better and reputation would come back and people would buy Montana again. I know it all about the almighty dollar!
Again this is my opinion!


Again thanks for all the information, all and my unit is

2024 3781RL Montana



Thanks

James Blackford Jr.

 

[loadmaster-MOC]

I have the same problem with my New 2024 3781RL! I'm pissed at this also.

 

[Ozzie66]

James, thanks for the update on our AC ductwork issue. We have the same ac ductwork "blockage" on our 2024 3123RL. Three weeks ago, I reached out to Keystone customer service. I have not received a reply from Keystone. Thank you again and I appreciate your efforts on this issue.
Ozzie

 

[kyjoe1]

I have a 2023 3781RL. My race way is complete. In mild weather, I can cool the entire rv with the front a/c to keep noise at a minimum. The heat pump will heat the entire rv. Again, mild weather. I cannot for the life of me figure out who came up with the idea to separate the raceway? That seems to defeat the design. I will also say that the blade system vents are an absolute joke. I cut all of the middle fins out of the vents to promote reasonable airflow and it has been a game changer. Sometimes I am not sure that the people that design these actually use them in real life situations. The lab is one thing. Life is another. Sorry that evidently they have changed the design for the worst and will not own up to it. Mind boggling!

 

[Ozzie66]

Update 9/16/24 on the 2024 3123RL blocked A/C ductwork:

A fellow owner got this reply from his dealer re the blockage in the A/C ductwork:

Well I got the answer from the service manager yesterday. This is intentional and supposed to be that way so the one rear unit can heat the main living area without losing airflow to the front.
We just got back from Great Basin and with temps in the upper 80’s, it cooled the interior down to the low 70’s.[/QUOTE]

Craig, Thank you very much for that info. I can see the point of the blockage for our "dual" A/C system. We spent July and August on the Oregon coast at Winchester Bay in Oregon. It would get down to 50 to 55 at night and I would use the heat pump in the rear area early morning to heat that area with the fireplace also turned on. It worked out nicely as the bedroom would not heat up while sleeping in. The drawback is no raceway for airflow if one A/C goes out. So much ... for the hype about the fabulous raceway airduct system. We were in Ely, NV a few days ago with temps in the 90s and the RV easily cooled down to low 70's.

 

[Bourbon County]

This seems to me as more of a "knee jerk" reaction rather than "intentional".

I watched a video from Keystone not long ago and they were explaining their duct system and their improvements. The improvements included long radius Ells, airtight connectors between sections, and airtight end caps. All of these things are pretty critical for a good duct system; I would contend that lining the inside surface with at least a foil surface to reduce friction would be another good improvement. There are at least some designers at Keystone that understand air flow.

Back to the plywood blocks; rather than putting the blocks in, why not just install 2 separate shorter duct systems and end them just past the last vent on each? It would save money in materials and labor. The space in the ceiling that would have been occupied by the needless ducts could be insulation filled and improve the overall thermal envelope of the RV also.

I suspect the systems are installed this way so if dealers get customer complaints or warranty claims, they have instructions to just punch the plywood out and give the owner some BS explination.

 

[C&P RV]

I recently took a factory tour and can tell everyone that the newer Montanas have 'zones' and are no longer interconnected. The ductwork ends about 18" on either side of the center vent (also the designated location of a 3rd 'dump' style AC unit. If you punch out or try to drill holes in the end of the duct from either the front or rear of the coach you will pump airflow into the ceiling void space. Keystone did this intentionally to maximize the airflow at each end of the unit. They got some negative feedback from owners at the rally because of the limitations (no heat pump to the bedroom area, inability to run the AC in the living area at night and still cool the bedroom, use of a single unit in a 30 amp campground, boondock implications, etc.). Most dealers aren't aware of the change as it's all hidden in the ceiling/ roof. And some of Keystone's repair techs weren't aware until the end of the rally.
The change was made based on airflow studies measuring output at vents vs the old 'raceway' where air would circulate in the duct system but not drop through the vents into the living space. I'm not defending...just repeating what we heard on the tour and during the rally.

 

[Ozzie66]

Clark & Peggy, thank you very much for that information. Now we "know the rest of the story."

 

[Carl n Susan]

...The change was made based on airflow studies measuring output at vents vs the old 'raceway...

How much do you want to bet the study was done with the new ducts that stick up into the raceway blocking the flow along with too many fins preventing air from exiting the duct???

Once again, the design doesn't consider actual usage.