13,500 BTU A/C on Keystone Outback

[wu367]

Purchased a brand new 301BQ Keystone Outback and took it on the first weekend camp trip this weekend. Went to Oklahoma where the daily temps were 105+. The interior of the camper was so hot we could barely stand it. The main cabin area would not go below 88 degrees and the rear bedroom was a sultry 92.

We tested the air going into the a/c -- 88 degrees as well as what was coming out of the a/c -- 68 degrees, but the interior would not cool down.

Is this a/c unit too small for the size of this unit? Would upgrading to the 15,000 BTU unit solve our problems or are we just doomed to sweat & suffer.

We love the trailer and the floor plan, but DW is refusing to camp in it again unless I can find a solution -- thoughts/suggestions??

[Bob Landry]

That's not enough air, even ducted, for that size trailer. 88 degrees return and 68 degrees supply is a 20 degree split. That's what a properly functioning AC should do, so that's evidence that it's not big enough to cool the trailer. I have the 277RL and after towing it all day with the sun beating down, it still takes 2-3 hours to cool down to where it's comfortable. After that, it runs quite a bit during the day, but it will eventually start cycling off. The dealer I ordered it from down in League City, Tx said they order everything with a 15KBTU. I had a Jayco 22 with the 13.5K in it and it struggled. I don't understand why they don't order everything with the bigger AC units. It's only a $146 upgrade.

[Me.Bikes.Dogs]

My 300MP with one 15,000 btu A/C can keep it about 10-12 degrees below the outside temp when the trailer is in full sun. I'm adding a second 15,000 unit in a week or two. Is your Outback wired for a second A/C? Upgrading to a 15,000 won't solve your problem. You either need a second A/C, cooler temps, or some shade!

[GMcKenzie]

I'm a bit surprised. Had my 30RKS in Vegas for 5 days, a couple saw 110+. It kept the trailer cool. I'd leave it on low all day until I got back, crank it onto high and it would pull the temp down. Maybe to 80 which felt fine after being in 110 on the strip all day.

[jq1031]

All of the comments above are on the mark. My Laredo has the 15 BTU & still takes at least an hour to get cooled down in 90 degree temps. In Vegas four years ago it was 117 degrees on the 4th of July. Our motor home had two 13.5 units & still we never got below 85 during the day & that's with shades down & the front windows had black screens that block ultra violet rays. You will do better with the 15 verses the 13.5, however the cost to change it out is not worth it!

[gepaine]

jq1031 got a 32 degree temperature drop when it was 117 degrees in Lost Wages. I think that was fantastic performance by his A/C system!

I've always been told that a properly sized and functioning A/C system should be able to deliver a 10-15 degree temp drop (outside temp minus inside temp) - that's all I should expect whether it's a house or RV. And that has always been comfortable for me. Of course, I've never been in Las Vegas when it was 117. Humidity is what kills me so anything below 85 with low humidity is quite comfortable to me.

[Bob Landry]

Originally Posted by gepaine

jq1031 got a 32 degree temperature drop when it was 117 degrees in Lost Wages. I think that was fantastic performance by his A/C system!

I've always been told that a properly sized and functioning A/C system should be able to deliver a 10-15 degree temp drop (outside temp minus inside temp) - that's all I should expect whether it's a house or RV. And that has always been comfortable for me. Of course, I've never been in Las Vegas when it was 117. Humidity is what kills me so anything below 85 with low humidity is quite comfortable to me.

A properly functioning AC, be it home, boat, or RV operates with a 20 degree split across the evaporator coil, AKA delta T. That's the difference in the temperature of the return air as it is drawn across the coils and the temperature of the discharge air at the grill. Outside ambient temperature does not figure into this as you are recirculating air from the inside, not bringing it in from outdoors.

The outside temperature is relevant to the extent of introducing heat to the trailer via radiation, but that's about it. A 20 degree difference across the coil will verify proper AC operation, and if the space does not get cool, that the AC is improperly sized for what it's expected to cool, or there is just too much heat being introduced via radiation. I would think that the largest AC would have issues keeping up with anything except the smallest trailer in the Nevada or Arizona heat.

The above information pertaining to temperature difference and cooling efficiency also depends on the evaporator and condenser coils being clean and that any ducting is properly sized and installed.

[gepaine]

I wasn't saying anything about methods for determining proper operation. (I'm not disagreeing with the last poster, but I think he miunderstood the intent of my post.) I was only saying that people need to have realistic expectations. As an example, if it's 100 outside, I think expecting any A/C to get the inside down to 70 is just being unrealistic.

[Handysam]

Recently on a 12 day trip where temps. were in the 90's here, and having no shade on our fifth wheel. I was very surprised at how ours cooled in the mid day heat. We have a 15k btu and its a fiver, and initially when we bought it last fall I was concerned about needing a second a/c in the bedroom (which I like it to be very cold at night), but that wasn't the case. Friends of ours have a new Outback TT and have had trouble keeping it cool on a recent trip to Florida. When they returned, they took it to the dealer and had a new one installed under warranty, and problem solved. Happy Camping, Sam

[therink]

Originally Posted by wu367

Purchased a brand new 301BQ Keystone Outback and took it on the first weekend camp trip this weekend. Went to Oklahoma where the daily temps were 105+. The interior of the camper was so hot we could barely stand it. The main cabin area would not go below 88 degrees and the rear bedroom was a sultry 92.

We tested the air going into the a/c -- 88 degrees as well as what was coming out of the a/c -- 68 degrees, but the interior would not cool down.

Is this a/c unit too small for the size of this unit? Would upgrading to the 15,000 BTU unit solve our problems or are we just doomed to sweat & suffer.

We love the trailer and the floor plan, but DW is refusing to camp in it again unless I can find a solution -- thoughts/suggestions??

WU367,
Good advice from all.
I think I responded to your post on rv.net as well.
My only recommendation is (because your rig is new) to remove all round ceiling ac vents and make sure all factory installed foil tape is installed properly. Improperly installed or loose tape will cause precious cooled air to flow into the ceiling cavities, therefore minimizing the flow rate and efficiency of the system. The first thing I did when I got my new Outback home last year was retape all vents. I was amazed (but not surprised) at how sloppily the tape was installed at the factory. I used the thicker type foil tape that molds well to where you apply it and used an entire roll.
I also removed the inside ac filter, dropped the cover and retaped several areas on the Plenum that were allowing air to go where it shouldn't.
I am very happy with the way my ac works, but then again, I haven't been in 100+ temps. Many days of 90+ with no complaints.
Steve

[Johnnyfry]

All good points but remember that every light bulb, operation of the stove and microwave increases the heat load the A/C has to contend with. Also, keep shades down or, better yet, cover the windowed with Al foil during the day. Park in the shade if you can. Every little bit helps.

John

[wu367]

Thank you all for the advise. I am in process of retaping vent connections and sealing up AC plenum area. We will see if this helps. Again, Thank you

[Terrydactile]

Originally Posted by wu367

Thank you all for the advise. I am in process of retaping vent connections and sealing up AC plenum area. We will see if this helps. Again, Thank you

If there are gaps and you tape them up it should help/fix your problem. I had to do this on my rig and it made a big difference. I had huge gaps in my vents and up inside the plentum. The holes they cut in the duct for the vents looked like they were cut out with an axe. At least some 1" gaps in places. I also found the the ends of the duct runs where leaking. To solve this I cut a length of foam pipe insulation of the right diameter and length and inserted it up through the last vent in the run and positioned them in the duct work. They were wedged in because they are slightly oversized.

Taping may not solve your issue but if there are gaps its a big step in the right direction. You don't stand a chance in the summer heat if you are blowing cool air into the attic space. Let us know what you find and how it worked.

[Bob Landry]

Good suggestions. I havn't thought about checking the taping on my ceiling registers, but it certainly seems like a worthwhile thing to do.

[ckittila]

I have a 2011 301BQ and am suffering the same issue as the original poster. The airflow to the rear of this model camper is very weak and the temperature easily exceeds 90 during the day. I was seriously considering ripping out the factory 13.5K ac unit and upgrading to a 15K unit, but I don't see how an addition 1.5K btu is going to make much of a difference here. I don't understand (actually I do) why Keystone doesn't just build this unit with the bigger ac unit.

Thank you for the information about sealing the ductwork. I am going to examine this right now. Perhaps this is part of my issue.

There is enormous airflow to the front ducts of this unit and very little to the rear air ducts. Is it reasonable to put a damper on the front ducts to increase airflow to the other ducts in the rear of the unit?

[therink]

Originally Posted by ckittila

I have a 2011 301BQ and am suffering the same issue as the original poster. The airflow to the rear of this model camper is very weak and the temperature easily exceeds 90 during the day. I was seriously considering ripping out the factory 13.5K ac unit and upgrading to a 15K unit, but I don't see how an addition 1.5K btu is going to make much of a difference here. I don't understand (actually I do) why Keystone doesn't just build this unit with the bigger ac unit.

Thank you for the information about sealing the ductwork. I am going to examine this right now. Perhaps this is part of my issue.

There is enormous airflow to the front ducts of this unit and very little to the rear air ducts. Is it reasonable to put a damper on the front ducts to increase airflow to the other ducts in the rear of the unit?

Sure, no reason why you can't install a damper, as long as itcdoesnt restrict airflow and choke the ac. Another thing I did was tape off the ends of the main ducts at the last vents in the front and aft duct runs. On mine, the ducts extend 6" or so further than the end vents. I figured that it didn't make sense to have air flow past the vent to dead duct space. Putting foam or pipe insulation in there would work too. HVAC systems need smooth and unresticed ducting to vent openings to move efficiently. I will say I'm pretty satisfied with the way my ac works in my 329fbh.

[ktmracer]

I have a 295RE and it is pretty big for a 13.5K single A/C. However, ours also had trouble cooling the bedroom down and as well as the rest of the trailer. doing the following helped tremdously. Most of the mod's could be done on other larger outbacks as well.

1) Open up the access panel to the ducted air. Check and make sure the openings to the ducting are cut to the full allowed size, bet they aren't, if not cut them open as much as is allowed
2) Use aluminum ducting tape, tape off and make sure there are no gaps or open areas in the plenum that would let air into the ceiling. You want ALL the airflow into the ducting.
3) replace the existing vents with "airport" vents. you can get them from suppliers on the web. it allows you to close off a vent, specifically, the one you want to close off is the living area vent in the duct going to the bedroom. instead of a directed air, it blows air 360 degrees across the ceiling. you just run the vent and it will screw and unscrew, opening or closing the vent to control airflow.
4) Add another ceiling vent in the bedroom. the ducting goes beyond the vent in the bedroom, so it is easy to add a second vent in the bedroom
5) Add another vent in the bathroom, goes into the same duct going to the bedroom.
6) to cool the bedroom, close the bath door and the folding screen in the bedroom.
7) take off all the vents and make sure they are tightly sealed between the ducting and ceiling. More than likely there is an open gap on some/all between the ducting and the ceiling, so air is going into ceiling as well as the living area.

if you do the above, you can actually get the bedroom about 5 degrees cooler than the living area! (and still keep the living room comfortable) If you do (1) (2) (6)(7) you can get the bedroom at least as cool as the rest of the trailer, most likely a few degrees cooler if you are using the ducted air. opening the direct vents pretty much limits the air going through the ducts, so ducted air doesn't do much.

And, if you want even better overall cooling
Add another vent in the living area just after the ducting to the bedroom makes it's turn from the plenum. It will put a vent close to the dinette which is nice. Basically, you want minimum restriction in the ducting, the more vents you install, the lower the restriction, the higher the airflow.

Several folks have followed the above suggestions and commented that they felt the mod's made a substantial improvement.

[ckittila]

Originally Posted by ktmracer

Basically, you want minimum restriction in the ducting, the more vents you install, the lower the restriction, the higher the airflow.

Several folks have followed the above suggestions and commented that they felt the mod's made a substantial improvement.

Thank you for all of the suggestions. I think your last statement may be the key. More vents, more air flow. This will be the tactic that I try for my camper, because it looks very straight-forward to do and I can tell I have plenty of pressure in the main duct to support the additional outlets. I believe that this camper, being bigger will benefit from more air flow out of this a/c unit.

Naturally, after I do this modification, the temperature will never reach 95 again this year, so I won't know the results until next year!

Thanks!

[burt78]

I retaped all of my vents and plennum in my 260FL and also added a "damper" to the bathroom vent to keep the bathroom from being so cold and to direct more air to the bedroom. I could tell a bit of a difference. This is the damper before I put the vent back on.

[Bob Landry]

How does the rotating grill part come out? I didn't see any screws and I didn't want to just start pulling on it.