AC not keeping up

[taylorbob1]

I just completed the AC mods as suggested on the Forum
1) made sure the divider was perfectly placed and taped inside the housing separating the intake from outflow
2) moved the thermister so it is now "dangling hope-lessly" vs inserted inside a coil fin
3) added the extra 4" round vent directly to the AC cover

These mods have really increased the cooling.

Although I'm currently at Oceanside Beach (San Diego Area) where it's a cool & breezy 72 degrees today.
So the AC is naturally occurring, off the Pacific Ocean.

[Long & Winding road]

Really all we are doing is making the factory AC unit work as well as it can by fixing leaks, moving the probe, maximizing airflow, rejecting outside heat etc.

We are not modifying the actual mechanicals. Just doing the best we can with what we have.

Im sure when ("IF") they "bench test" these units at the Colman factory they are testing inside a building (shade and relatively cool), no duct work to worry about air leaks and they have the divider in the correct location to verify the 15 to 20 deg air difference in air temps (Hot vs Cold side). They might even get 25 deg.

Then the RV manufactures screw everything up with inproper installation, air leaks, blocked ducts, divider moves inside unit and they dont check it. Probe moves and the install where ever they want etc.

So the AC suffers and then we write threads like this to help correct the easy problems.

So really THor is doing us a favor with the poor QC .... otherwise we would have nothing important to talk about on this forum and nothing to mod on our RV's since everything would be perfect.

Life would be so boring. LOL

[Long & Winding road]

Originally Posted by taylorbob1

2) moved the thermister so it is now "dangling hope-lessly" vs inserted inside a coil fin
.

Someone mentioned this last year. How did that work out? Did you test the output temp? What is it?

[mstng]

Exactly LWR, The AC isn't the problem, it's the install or not enough BTU for the length of the coach. There are fixes that dramatically improve temperature and air flow.

I think that on a 100 degree day if you can't get the output temp directly below the blower in the low 50's or upper 40's you're not getting what the AC is capable of providing. I started with temps in the mid 60's and fixing the baffle brought the temp down 15 degrees. Then it becomes a matter of capturing that air and distributing it. I took the easy way with the extra vent below the blower but if my RV was larger the only thing that would have helped would be an additional AC.

[mstng]

Originally Posted by taylorbob1

I just completed the AC mods as suggested on the Forum
1) made sure the divider was perfectly placed and taped inside the housing separating the intake from outflow
2) moved the thermister so it is now "dangling hope-lessly" vs inserted inside a coil fin
3) added the extra 4" round vent directly to the AC cover

These mods have really increased the cooling.

Although I'm currently at Oceanside Beach (San Diego Area) where it's a cool & breezy 72 degrees today.
So the AC is naturally occurring, off the Pacific Ocean.

Would be interesting to see how the input and output temps change with your probe in different positions.
I use a dual barbeque temp probe that I verified calibration with another thermometer. Interestingly moving from the blower to the first vent in the hallway (24.1) temp increased only 3 degrees, 1st vent in bedroom up 5 degrees, and last vent near the back increase of 10 degrees. Others are probably much better insulated than mine though. LWR has done quite a bit of duct work that lowered the difference in temps.

[taylorbob1]

Originally Posted by Long & Winding road

Someone mentioned this last year. How did that work out? Did you test the output temp? What is it?

Regarding thermistor...
I can’t really tell yet, but assume it’ll make a difference
The concern is coil freeze-up as stated on the Forum.
But I’ll keep an eye on it

By the way...I also blocked the end-runs of the ceiling channel vents

Time will tell & Ill report back

[ducksface]

So...
I haven't bothered to do an investigation but when I look up into the overhead ac vent, the one at the foot of the passenger side bed, nearest the bathroom wall, over the TV, I can see a daylight glow through it. Just a glow, but certainly daylight. What's under the roof membrane that would allow that?


I haven't done any ac mods yet.
Except for the dash air freezing up(in for warranty repair right now), and this is just a matter of hitting the ac button to turn it off for five minutes or so, we find the ac in our 24.1 serves us well enough.

[Long & Winding road]

Originally Posted by ducksface

So...
I haven't bothered to do an investigation but when I look up into the overhead ac vent, the one at the foot of the passenger side bed, nearest the bathroom wall, over the TV, I can see a daylight glow through it. Just a glow, but certainly daylight. What's under the roof membrane that would allow that?


I haven't done any ac mods yet.
Except for the dash air freezing up(in for warranty repair right now), and this is just a matter of hitting the ac button to turn it off for five minutes or so, we find the ac in our 24.1 serves us well enough.

Its the rear clearance lights. I noticed that one my Axis if you pull out the corner trim at go horizontal from the L to R side of the coach along the ceiling (at least on my floor plan.... I dont have Over Head cabinets on the back of my coach like the 24.1 has). I was going to remove and add silcone if need then insulate but never got around to it. Im not sure how its held up and I dont want to break any plastic clips.

[sandrooney]

Just installed the round vent and it really blows out some air. Also just finished installing a second A/C in the back. A/C w/ ceiling assembly $700.00, 2- 25' 10 gauge cords $ 48.00, 25 foot of 12/2 romex $10.00, and an RV inlet plug $14.00. Labor free. Best $772.00 I ever spent.

[mstng]

Nice, with 2 AC in a 25 foot you’re ready for Florida

[Long & Winding road]

Great. Post some picks when you get a chance.

[Long & Winding road]

Originally Posted by mstng

Nice, with 2 AC in a 25 foot you’re ready for Florida

Heck, he ready for the the Desert in the middle of the hot season!

[The Gritz Carlton]

2 A/C should be standard. Last week, in 97 degree full sun with both units running, it was 67 degrees inside. I "heart" A/C. Sleeping with blankets in the heat of summer...priceless!

[Mousemate]

Originally Posted by The Gritz Carlton

2 A/C should be standard. Last week, in 97 degree full sun with both units running, it was 67 degrees inside. I "heart" A/C. Sleeping with blankets in the heat of summer...priceless!

Same here ... even better when you are not paying the electric bill😁

[mstng]

If mine was any bigger I would get another one as well. Some of that additional electric cost would be mitigated by them running less.

[rellis195]

I have a 28 ft Four Winds Citation Chateau (Class B-Plus). This has ducted air from a single air conditioner. Living in Florida we are constantly battling the heat. We visited the Keys in 95 degree weather, and our coach never got below high eighties all day.

We tried cleaning the filters and washing the condenser fins, and washing the fan blades but it made little if any difference. I then checked the cold air entrance to the unit and found that some cold air was being sucked back into the return. Half a reel of duct tape later that was fixed, but there was still not enough cool to go round.

So, I removed the Dometic Penguin II 13.5k low profile unit, and purchased a Dometic Brisk Air II 15k. The new unit is a full height unit. I do not know whether it is the 11% increase in power, or the increased area of the condenser fins allowing more air to flow thru, but it makes a big difference.

I also have the ability to direct all the air directly in to the living area, and bypass the ducts.

Normally an AC unit should show about a 20 degree fahrenheit drop between in intake and output.

Happy perspiring!

[sandrooney]

I now have a 15,000 in the living area and a 13,500 in the bedroom. I should be good to go. Axis 25.2

[Chance]

Since Thor made the 15,000 BTU/hr A/C standard on Axis/Vegas a few years ago, they should now offer dual 11,000s as an option like they do on some of the larger Class Cs.

I’m interested in knowing what they charge for that option; considering it uses same 4,000-Watt generator and 30-Amp electrical service. It should be worth it for those in warmer climates. I plan to look it up out of curiosity.

[sandrooney]

Can you run 2- 11,000 a/c's on a 30 amp circuit? I kept my second a/c on a separate 20 amp. I just plug it into the 20 amp at the pedestal and the RV into the 30 amp.

[Chance]

Just looked it up — the 2 X 11,000 BTU/hr A/C with Power Management option on a Chateau Class C has a MSRP of $1,313.

That’s not bad. With typical markup, we should be able to get it for under $900 or thereabouts. My original estimate of about $1,000 wasn’t too far off.

I’d pay that any day to upgrade A/C at factory on an Axis.



And yes, it will run on 30A service or 4 kW Onan generator.