13.5KBTU Is not cutting it

[jholovacs]

I have a large RV (Outback 298RE) and I love it. I think it's well-designed, except for a few things... like A/C.

Mine came with a 13.5KBTU A/C ducted unit. This is completely unable to knock more than 10 degrees off outdoor temp, 15 if not in direct sunlight. On an 85 degree day, that's fine, but when camping south of the Mason-Dixon in summer, it's not unusual to see 100+.

The camper is wired for 30A, and barring ripping the whole thing apart and wiring for 50A with two A/C units (which seems ridiculous) I seem to be stuck with going with a 15KBTU, which does not seem especially better to me.

How do people handle this this sort of thing? I like to play in the sun, but I definitely like to sneak inside and soak up some A/C, and sleep in 85+ temps is torture.

Are there higher-BTU A/C's available that won't blow a circuit? Some special insulation tips that make a noticeable difference without being noticeable? Improvements in the ducting/ air circulation that seem to work? Anything?

[L_R_G]

+1 to adding more registers. If you look at your manufacturer's documentation for your A/C unit I bet you'd be surprised at how many square inches of outlet space it's supposed to have; and that your trailer doesn't have as much as it's supposed to. I added a Dometic Genesis filter to mine which includes the quick cool dump vent. That made a huge difference for me. I had nowhere near enough area for the air to blow through before.

[LarryJM]

jholovacs wrote:
I have a large RV (Outback 298RE) and I love it. I think it's well-designed, except for a few things... like A/C.

Mine came with a 13.5KBTU A/C ducted unit. This is completely unable to knock more than 10 degrees off outdoor temp, 15 if not in direct sunlight. On an 85 degree day, that's fine, but when camping south of the Mason-Dixon in summer, it's not unusual to see 100+.

The camper is wired for 30A, and barring ripping the whole thing apart and wiring for 50A with two A/C units (which seems ridiculous) I seem to be stuck with going with a 15KBTU, which does not seem especially better to me.

How do people handle this this sort of thing? I like to play in the sun, but I definitely like to sneak inside and soak up some A/C, and sleep in 85+ temps is torture.

Are there higher-BTU A/C's available that won't blow a circuit? Some special insulation tips that make a noticeable difference without being noticeable? Improvements in the ducting/ air circulation that seem to work? Anything?

I would recommend you look at the number of registers and consider adding some and like donno suggested putting two either right at the air plenum or like I did right at the junction of the main air plenum and the duct run on each side if that is your configuration. This will allow for increased cooling in the area around the A/C itself and being able to close off some registers in spaces like the bedroom and bath during the heat of the day and not effect the overall cooling of your system. Some think you can shut off some registers to redirect the cooling, but w/o the proper number and free air register openings you can actually make the problem worse.

Please tell us what A\C model you have, if you have two duct runs (one on each side of the A/C, if your ceiling is foam board insulated, and the number and location of the existing registers and where in relation to the floorplan those are.

I added like 6 more registers with two at the main air plenum to duct run intersection and that solved all my cooling issues even in close to 100 deg outside temps.

While a second A/C is an option what I have described can be done for well under $50 and might be all that is needed.

Larry

[LukeS]

I had similar issue added fans to each side of living area, and in the bunk areas and bedroom. Amazingly it works without doing to much that is costly. I do like the idea to cover the slide with an ez up. Just remember to support it from winds etc.

[hitchup]

Even though we have a highly insulated 5er with dual panes and 2 AC's (15k n 13.5k), I still keep the dual cell shades and lined curtains closed when sitting in the hot southern sun.

We also have a door and slide awnings, vent pillows and a shade on the shower skylight. Plus keep table and tower fans handy to move the air. I have no problems keeping inside temps at 74-76 in 100+ degrees. Any cooler and I would need a sweater.

[johnm1]

We have a 15K BTU A/C (30A service) and it does a good job for us. We've been to Virginia Beach with temps just above 100 and, while it didn't shut off much, it was quite nice inside. We also have slide toppers on our slide outs and use the main awning which helps keep that side cooler. We also turn the A/C fan to "ON" all the time (not "AUTO") and it seems to help move the air around. A side benefit is it helps drowns out the rowdy neighbors at night!

If you add a 2nd A/C unit, or swap the 13.5K for a 15K unit, (and don't run a separate dedicated line to it) and you use "extra" stuff (spare fridge, hair drier, etc.) you might have to manage your power usage with only 30A coming in.

Just my 2 cents!

[bigcitypopo]

You have to remember. That cool air sinks... So your trailer is a cold well. A 13.5k a/c is plenty if your rig is well insulated. Close your furnace vents. Cut a sheet magnet for the vent. Place a small to medium vortex type fan in a spot where it'll blow across the room. You should notice a huge difference. Air movement is key. I also have reflective mats for the windows. My aljo had a 13.5 ducted. I never had issues in 100+ weather. Trailer was always 75-80 our hottest day was 109. Just compartmentalize as best you can. Keep the air moving.

[TOOBOLD]

Here's what we do on those really hot days 104. I put reflective car shades in the windows that face the sun, next awning out, place an easy up next to or over the slide for additional shade.

Stay home for any temps higher than 104.

[ScottG]

Terryallan wrote:
As I remember, and I'm not 100% sure. But I believe a 15 to 20 degree drop from outside temp is about all your gonna get.

I think your confusing temperature drop through the AC itself (16~21 degrees is normal) with temp drop from outside.
A trailer with sufficient AC can drop the inside to comfortable temps no matter how hot it is outside.

If it were me and I already have a good working 13.5, I would add a second smaller AC - maybe 9K.

[Desert_Captain]

We see lots of questions on this Forum by newbies as to what to look for that reflects a quality built trailer. Given the serious impact they have on the overall quality of life the heating/cooling systems are just such a benchmark. If the trailer is 25' or more and comes with a 13,500 BTU AC system you had better hope you won't need it much. I frequently see 30'+ TT's with a single 13,500 system, who are they kidding? if the builder went that cheap on such a critical system you should ask yourself what else did they skimp on that I cannot (easily), see.

Our 22' TT has a 13,500 (non ducted), AC and it is adequate but by no means too much, on a warm, much less a hot day. As noted above you cannot reasonably expect to get more than a 20 degree differential between the outside temp and what the AC puts out. I wish ours was ducted to reduce the noise and probably enhance the efficiency (but that is just speculation on my part). :C

[aarond76]

1. The air conditioners usually do a poor job seperating the supply side from the return side in the unit itself. I took the interior cover off mine and taped it all up good with foil tape between the intake and discharge side. What happens is you end up pulling the cooled supply air back into the return and it does not work as well. This made a huge difference for me. We have a 32' stick and tin and it cools it well. I have to believe you are better insulated than me, try this first. Also check to make sure your filter is clean and look up inside the unit and make sure the coils are not dirty.

2) Most people say 15k makes a substantial difference over 13.5k. I agree it does not sound like alot but look at it this way. 150 hp does not seem like alot more than 135hp until you get to a hill that requires 145 hp to climb... The extra 1.5k might be enough to make up all the difference in the world.

3) Some people will add a 2nd roof-top 13.5k A/C and run it off the 20Amp outlet on the pedestal.

[fla-gypsy]

I have a single 13.5 in a 29' box and camp in Florida in the summer time. I have added the vent pillows to the overhead vents, put reflectix over the opaque door windows, use the awning and find a campsite in the shade. It is always freezing (or so it seems) inside.

[tragusa3]

If operating correctly, you should measure about 20 degrees from the ingoing air to the outgoing air. So if the trailer temperature is 80 degrees, it should measure about 60 degrees coming out of a vent. Check if you're getting that. It will vary some depending on the load from outdoor temperature.

I was just at the beach in 92 degree daytime temps. I measured an 18 degree differential during the day, but at night I was getting a 24 degree differential. This is a differential from trailer temp to outgoing vent, not outdoor temperature.

[donn0128]

Turn the outlet so it is blowing straight down bypassing the duct work. Seems to work better that way for me

[Terryallan]

jholovacs wrote:
Hmm... I would need to find space for that, but it might be ideal... I'd probably want to run another circuit for it ( maybe pull off the separate 15A available in most RV sites)...

hmm...

What you could do. Is what we do for the outside fridge. Our TT is 30 amp. But we run it off the 50 amp service using an adapter. We then plug into the 30 amp, and run every thing outside on that. Fridg, griddle, toaster, fan. If we don't. We trip the breakers inside, and out.