Coleman Mach Q 15k AC's

[staab6708]

Hello - new Montana owner here. We bought a 2023 Montana 3857BR and we have two Coleman Mach Q 15k AC's. When the camper comes from storage and we head to a campsite the temperature can read 90 degrees in the camper. It takes the AC's 4 to 5 hours of running constantly to get the camper cooled down to 72 degrees. Our other camper (Forest River Vegenance Rogue Armored Toy Hauler) which had two 15k AC's as well (unsure of brand) and same scenario it was cooled down in under 1 hour. Has anyone else with the same AC's have this issue? I have an appt with service beginning of November to take care of some warranty issues and I want to bring this up as well. I am trying to come up with some examples so they don't tell me that is the norm.

Thanks

Jason Staab

[seasure1]

I noticed the same problem last week as we went to the Outer Banks. When we arrived it was 90 degrees inside the RV and took hours with both AC a ceiling fan and two portable fans to cool off the inside.

[Carl n Susan]

Lots of previous posts about poor cooling. Most common cause is collapsed vent or crappy outlets that block the flow. Do a Search and you will find a lot of info.

[Foldbak]

Change the vents to the louver style. The new vents suck. I changed mine and I can at least feel the cold air. Still take a few hours to cool the trailer.

[firestation12]

Originally Posted by staab6708

Hello - new Montana owner here. We bought a 2023 Montana 3857BR and we have two Coleman Mach Q 15k AC's. When the camper comes from storage and we head to a campsite the temperature can read 90 degrees in the camper. It takes the AC's 4 to 5 hours of running constantly to get the camper cooled down to 72 degrees. Our other camper (Forest River Vegenance Rogue Armored Toy Hauler) which had two 15k AC's as well (unsure of brand) and same scenario it was cooled down in under 1 hour. Has anyone else with the same AC's have this issue? I have an appt with service beginning of November to take care of some warranty issues and I want to bring this up as well. I am trying to come up with some examples so they don't tell me that is the norm.

Thanks

Jason Staab

Poor ducting is certainly one possible explanation, but realize there can be other factors at work. The temperature which the camper was “heat soaked” can delay the interior feeling cool. Air has very little mass and quickly cools 17+ degrees in the few seconds it takes to enter and exit the A/C unit. But the interior mass does not so quickly give up its stored heat. Arrival at a warm campsite can further delay your interior that started at 90, from dropping to the preferred setting. Interior comfort is a combination of air temperature factored with any radiant heat from the surrounding envelope. For example standing near a campfire offsets a 40 degree ambient temperature, or standing under a patio roof’s shade feels different than moving a couple of feet past the drip edge where direct sunlight hits your skin. The air temperature didn’t change in that 2 feet, but the radiant heat from the sun makes that 100 degrees feel different. Your camper’s interior temperature isn’t going to feel comfortable till every bit of stored heat (that is radiating to your body), is removed. Also remember that the output temperature of the ceiling A/C vents is dependent upon the input temperature. If the input temperature is 100 degrees, don’t expect the output temperature to be 60 degrees. At best you may see 100 -17= 83 (split). This 83 degree output air isn’t going to do much until the interior mass starts giving up it’s stored heat.

[bshgto]

Originally Posted by seasure1

I noticed the same problem last week as we went to the Outer Banks. When we arrived it was 90 degrees inside the RV and took hours with both AC a ceiling fan and two portable fans to cool off the inside.

And the OP thinks he needs examples of others experiencing the same thing?
The dealer hears it all the time and really has no fix. Alot of the problem is the exist temperature at the first vent. The colder the air the faster the unit will cool and it gets warmer the father you are from the a/c. The first vent in my unit was on 95-degree day was 50 degrees and at 70 at the last vent. This would take hours and hours to cool the camper from the heat soak. You can do what I did to put a generator in the bed of the truck and start the a/c`s 3 hours before you get to your destination to get it down to an acceptable temp when you arrive. That was expensive to execute and a bit of a pain to monitor.
The addition of fans or a 3rd dump style a/c just ads to the noise and that would drive me crazy. So I put in a 230 volt Mini Split, and it cools the whole camper in minutes not hours because the exit temps at the head unit is 31 degrees with the addition of a small fan at the top of the stairs to push the cool air into the bedroom. It heats down to 5 degrees, try that with keystones idea of a heat pump-a/c. My point is you cannot hear the mini split running on high unless you get real quiet and listen for it. Never going back.

[firestation12]

Originally Posted by bshgto

And the OP thinks he needs examples of others experiencing the same thing?
The dealer hears it all the time and really has no fix. Alot of the problem is the exist temperature at the first vent. The colder the air the faster the unit will cool and it gets warmer the father you are from the a/c. The first vent in my unit was on 95-degree day was 50 degrees and at 70 at the last vent. This would take hours and hours to cool the camper from the heat soak. You can do what I did to put a generator in the bed of the truck and start the a/c`s 3 hours before you get to your destination to get it down to an acceptable temp when you arrive. That was expensive to execute and a bit of a pain to monitor.
The addition of fans or a 3rd dump style a/c just ads to the noise and that would drive me crazy. So I put in a Mini Split, and it cools the whole camper in minutes not hours with the addition of a small fan at the top of the stairs to push the cool air into the bedroom. My point is you cannot hear the mini split running on high unless you get real quiet and listen for it. Never going back.

Nice job on the ductless split system. Does the rear compartment door still open fully? I’ve incorporated a free standing portable 14K btu unit made by Whynter model ARC-14S. Cost was $300 from Amazon after a $50 rebate. The 2 tube design (1 five inch diameter tube for inlet air to cool the condenser and 1 five inch diameter tube to discharge hot air from condenser to the outside plus evaporate all condensation. Took less than an hour to set up the first time and cools far better than a 15K roof unit. Not as quiet as your mini split setup, but pretty darn close

[Ren]

You need a 3rd AC. Two AC's are just not enough.

If you do get a 3rd coleman, have it directly dump out, don't tie it into the ducting. Your rig will cool down in less than an hour. We had 3 on or 3121rl, Two ducted and the 3rd one in the kitchen was not ducted. Been all in the Keys, All out west in NM and Texas and Arizona and 3 AC's are the way to go.

If you also have the Blade air vents, https://www.keystonerv.com/innovatio...ir-flow-system these garbage and absolutely horrific at getting the cool air moving.

I swapped all the blade vents out for the Thetford 94270 coolvents. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

When I got the replacement vents that helped huge! Unfortunately it looks like they are 20 bucks a piece now...yikes.

Hope the above ideas help you out.

Ren

[bshgto]

Originally Posted by firestation12

Nice job on the ductless split system. Does the rear compartment door still open fully? I’ve incorporated a free standing portable 14K btu unit made by Whynter model ARC-14S. Cost was $300 from Amazon after a $50 rebate. The 2 tube design (1 five inch diameter tube for inlet air to cool the condenser and 1 five inch diameter tube to discharge hot air from condenser to the outside plus evaporate all condensation. Took less than an hour to set up the first time and cools far better than a 15K roof unit. Not as quiet as your mini split setup, but pretty darn close

Yes the tray tilts down for full access. I was in a camper that had the 3rd a/c installed and all 3 were running, it was just to loud. I can imagine trying to listen to conversation or the tv. The min split is whisper quite.

[Ren]

As soon as the rig cools down, which for us is about an hour, ya don't need the 3rd one running so it gets shut down.

Then the front and rear get put on low. To say it's more noise. Dunno bout that. No more noisy than any other camper. Tons of us have 3 ACs. A lot of Class As all have 3. Pretty much all the GD 5ers have 3 now. It's pretty quickly becoming a standard.

[mleeder]

That seems pretty normal to me. A lot depends on how long the trailer has been at 90 degrees or more. Everything inside absorbs that heat and has to cool down as well.

[bshgto]

Originally Posted by Ren

As soon as the rig cools down, which for us is about an hour, ya don't need the 3rd one running so it gets shut down.

Then the front and rear get put on low. To say it's more noise. Dunno bout that. No more noisy than any other camper. Tons of us have 3 ACs. A lot of Class As all have 3. Pretty much all the GD 5ers have 3 now. It's pretty quickly becoming a standard.

Lol well I guess all those other people are wrong then

[firestation12]

Originally Posted by Ren

As soon as the rig cools down, which for us is about an hour, ya don't need the 3rd one running so it gets shut down.

Then the front and rear get put on low. To say it's more noise. Dunno bout that. No more noisy than any other camper. Tons of us have 3 ACs. A lot of Class As all have 3. Pretty much all the GD 5ers have 3 now. It's pretty quickly becoming a standard.

I’m 90 miles south of San Antonio and I can attest that a 3rd source of A/C is needed to comfortably endure the summer. In June, July and August 2 units were not enough to keep the inside comfortable. In many parts of Arizona where we were before being in Texas, it was pretty much the same story….2 15K A/C units were not enough on a 42’ 5th wheel.