Does anyone make an A/C larger than 15,000 BTU

[TexasRedNeck]

Curious, at 100 degrees the 15,000 struggles to keep up at times. Does anyone make a rooftop AC larger than 15,000? Say , like a 17,000? I have not been able to find one if they do.

Thanks as always

[RobertRyan]

Currently travelling around Eastern Europe. Insulation on Australian Caravans depends on the requirements. You do get Ice and temperatures well below freezing in quite a few places in Australia

[ghiotom]

Terryallan wrote:

dougrainer wrote:
The largest is 15k. If your RV is longer than 25 foot, a 15k will not be able to keep up in temps above 90 degrees and hi humidity. Doug

Really? My 13.5, on my 29' TT, does a great job in the high heat, and humidity of a Myrtle Beach July day. (read 80% humidity, and 100+ degree F) As long as the doors aren't opening, and closing every 2 minutes, and in truth. The main door is always open, with the screen door shut. It has plastic sheeting (plexiglass) covering the screen. Maybe it's the superior insulation values of the AZDEL construction.

Wow, that's some AC. Your heat index would be 164 degrees.

[pnichols]

TexasRedNeck wrote:
In this case, the heat and humidity of Texas are decidedly not something to brag about!

You got that right.

The heat and humidity of Texas are things to feel sorry for and move away from. I'll take the high desert summer heat in OR, NV, and UT any day over that stuff. BTW, if you think TX is bad ... try the neighbors along the coast to the East - been to Texas and the Eastern neighbors in our RV in August and had the campgrounds and attractions to ourselves except for the mesquitos and cicadas. Misery times ten. 😞

[69_Avion]

smkettner wrote:
Seen 118 in Vegas.... we head for the casinos until the sun sets :B
Humidity was probably negative so it does not count 😉

In Phoenix we hit 122. But it is a dry heat, just like your oven.

[dougrainer]

smthbros wrote:

C Schomer wrote:
They don't show net btu cap. 16/18kbtu must be gross btus. They're still pretty sorry ACs. 330 cfm isn't even enough cfm for an honest 1T AC. I'd like to know what the evap DT is and what the sensible and latent caps are. Craig

I suspect that a major problem with RV AC is that most RV manufacturers, most RV techs, and most RV customers, don't know what you're talking about.

You are correct as it is Greek to me (except the BTU and CFM), but there is NO REASON for anyone to know all that, unless you are trying to just show your knowledge and brag about it, when it has absolutely nothing to do with install and repair. Kind of like College professors that teach all day but have NO knowledge of the REAL practical experience out in the real world. Doug

[TexasRedNeck]

MEXICOWANDERER wrote:
"No offense to anyone outside of Texas, but unless you've been here in the summer, your reality may be a bit off (OK, some southern Louisiana and Florida folks may get a pass)"

Does 115F with 65% humidity (Xcalak Quintana Roo) qualify? Or 122F with 48% humidity (Ciudad Obregon Sonora) cut the mustard with Texan superiority?

Sir, please don't take it as Texan superiority, although we've earned the privilege of being thought of as arrogant. And in most cases, we probably have a right to be....;)

In this case, the heat and humidity of Texas are decidedly not something to brag about!

Those numbers would have me digging a deep cave and only coming out at night. Good grief!

[time2roll]

Seen 118 in Vegas.... we head for the casinos until the sun sets :B
Humidity was probably negative so it does not count 😉

[MEXICOWANDERER]

"No offense to anyone outside of Texas, but unless you've been here in the summer, your reality may be a bit off (OK, some southern Louisiana and Florida folks may get a pass)"

Does 115F with 65% humidity (Xcalak Quintana Roo) qualify? Or 122F with 48% humidity (Ciudad Obregon Sonora) cut the mustard with Texan superiority?

[Chris_Bryant]

The biggest problem with RV air conditioners is that they are designed to retrofit a roof vent opening- sending supply and return air through a shared 14" x 14" opening is tough.

[smthbros]

C Schomer wrote:
They don't show net btu cap. 16/18kbtu must be gross btus. They're still pretty sorry ACs. 330 cfm isn't even enough cfm for an honest 1T AC. I'd like to know what the evap DT is and what the sensible and latent caps are. Craig

I suspect that a major problem with RV AC is that most RV manufacturers, most RV techs, and most RV customers, don't know what you're talking about.

[dougrainer]

The ONLY answer in Texas Heat and Humidity is a 3rd AC on a 42 foot RV. There is NO WAY a 15k and a 13.5k will cool a 42 foot in Texas heat. ALL our RV's we sell over 40 foot have 3 AC units and my coworkers 41 foot DRV 5th wheel came with 3 15k AC/HP units and he has 4 slides and those units CYCLE and keep his family comfortable in 105 Texas heat. They are FULLTIMERS with 2 teenagers. Most of our 40 foot down to 36 foot have 2-15k units.
Last, a AC system does NOT have to run 100% to keep the moisture level and inside humidity down. A correctly functioning/sized AC system will cool most RV's and cycle. That may not happen during the 12 hours of the day at 100 degrees but will once the sun goes down. The BIG problem is what another poster stated---The INSTALL and how the gaskets and plenum system is sealed. ANY leakage will degrade the performance in hot weather and from MY observation, on systems that have the standard large return grill/filter in the ceiling, NONE are completely installed correctly. There is always room to seal them better. Doug

[TexasRedNeck]

greenrvgreen wrote:
The simpler answer is a third unit, if you have an available roof vent. Also, don't waste your time taking the A/C in to be checked--it works fine, I'm sure. As other have said, there is a limit to what an RV A/C can do, particularly if it is ducted.

If I was in your shoes, here would be my thought process:

#1. Are both A/C units running on compression 100% of the time? If either unit is cycling, then you have TOO MUCH A/C capacity for the volume of your unit--or you have insufficient circulation of cold air in the cabin.

#2. I would check the ducting for leaks that are pretty much guarranteed to be there. If I really felt like fiddling I would tape the ducts up, or

#3. I would disconnect one or both A/Cs from the ductwork. Let them blow cool air directly into the cabin, and use a portable fan to circulate it.

#4. I would add the third A/C, if nothing else worked. IMO, the most important thing about an A/C is that it stays on compression 100% of the time. Don't give it the opportunity to pour wet, clammy air into the cabin. If you don't need so much cooling, turn the third A/C off and make the other two run 100%, and then turn the second off, leaving the first to run 100%. In my 18-ft TT I run a 6k (6,000) btu A/C for hours on end--and I stay away from Texas.

The master bedroom AC will cycle but not the main. I question how well the front AC pushes air to the rest of the unit since it is, in essence, trying to force air back down a duct that the main unit is pushing air forward. Of course it can cause the main unit to push more air rearward, but I don't see much cold air from the front AC actually cooling the rest of the unit.

Maybe the answer is 2 13,500 in the main area that can be controlled independently during hotter weather. I'd hate to give up my fantastic fan, though. Of course the other is to be happy at 76 on a hot day.

Forgive my ignorance here. Other than removing the distribution panel below the AC unit on the interior and checking the tape in the transition from the opening to the ductwork how does one seal other parts of the duct work since it is behind the ceiling panels? Should I remove the round vent grills in each room and check the transition from the duct work to the ceiling vents too?

[time2roll]

TexasRedNeck wrote:
By the way, what is a basement AC? Is it like a ductless mini split for RVs? Never heard of that.

24,000 BTU with two compressors. Used in tall RVs where there is no roof clearance or it just fits better in a lower compartment. Ducting is in the floor similar to the furnace.

http://www.rvproductsshop.com/2ton-basement-airconditioner-w-hp-24-000-btu-46515-811.html

I know my 13.5 ducted roof air leaks into the ceiling because if I take an electric wall plate off there is positive cold air flowing out :R

[C_Schomer]

They don't show net btu cap. 16/18kbtu must be gross btus. They're still pretty sorry ACs. 330 cfm isn't even enough cfm for an honest 1T AC. I'd like to know what the evap DT is and what the sensible and latent caps are. Craig