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Old 06-18-2015, 02:43 PM   #1
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Do you stay cool with only 1 A/C unit?

This week is our first week staying in our new Cougar 301SAB 5th wheel. We're learning so many things. Luckily, so far, all systems are working properly. However, we have only one 13,500 BTU roof-mount A/C unit and are finding it difficult to stay cool in the 110 degree Arizona heat. The A/C unit just cannot keep the RV cool during the heat of the day.

Overnight it actually gets rather nippy in the RV with the A/C set on 75. It's nice enough in the morning until about 11:00 a.m. and then it starts slowly heating up in there. Today it got up to 90 degrees inside by noon with the A/C running full blast on a setting of 70 and two stand fans running to help circulate the air in the rig. Then again, in the evening time, about 7ish the A/C is finally able to cool it down to a comfortable temp inside.

I walked in one day last month (while the RV was in storage with no A/C running) and the inside temp was 110 degrees!! This was actually before it even got hot here in AZ. Summer is just beginning here.

This also seems to greatly affect how well the refrigerator cools, or so it seems. When the inside RV temp is comfortable the fridge works well; but, when it reaches those 90s inside, the fridge struggles. The freezer seems to be less affected. We currently have the fridge on its max cool setting but it took well over 24 hours for it to reach a temp of 40 degrees once we first hooked up to electricity.

Luckily, we live in the same park that we are doing our trial week in. We live in the manufactured home part of the park and we have rented an RV space in the RV section of the same park, to do a trial week in the RV to see how all the systems work and get a feel for what it may be like to eventually live in it fulltime, once we sell our house. So, we have the convenience of our nicely cooled home (thank you central air) to go to during those periods of the day that it's just too uncomfortable to stay in the RV.

We have quickly learned that it's going to need a second A/C unit installed, that's for sure!! Our RV is 34' long. Does anyone get by with just one A/C unit in extreme temps? If not, what do you do to compensate?

We see many other 5th wheels and some motorhomes in the park that also have only 1 A/C unit on top and we know the people are living in them either fulltime, or as long as they are parked here in the RV park. They too are enduring the same 100+ temps outside. I haven't seen anybody lounging outside in the heat to inquire, but, I really wonder what the temp is inside their rigs!

Any suggestions on ways to help the refrigerator do it's job in extreme temps?

How many of you have added a second A/C unit? Did you do a second roof mount, find a small window unit to use when needed, or do you use a portable A/C unit and just drain it in a sink or the shower?

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Old 06-18-2015, 02:52 PM   #2
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I used to have a 30 foot Thor ACE motor home with 1 15,000 AC unit. I had very similar experiences to yours in high outside temperatures. I eventually installed a second AC unit where the roof fan in the bedroom used to be. With two AC's running I was able to keep the internal temperature below 80 in 105 degree outside heat.

Regarding the fridge, in general try to keep that side of the RV as shaded as possible, keep the vents clear and make sure the vent fan (if installed) is running OK. I know that some owners have added vent fans. We are currently in the Florida Keys with outside temperatures around 90. The Dometic fridge is at 33 degrees and the freezer section is at 3.5 degrees.

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Old 06-18-2015, 03:04 PM   #3
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We are going to Utah and Arizona in July and have only one AC unit. Does anyone know if it helps to pull slides in during the heat of the day?
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Old 06-18-2015, 03:11 PM   #4
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In temps like that, it takes 2. 15000 units to keep my 38' motor home comfy.Pulling the slides in would probably help as most slides have thinner insulation than regular sides & roof, plus a little less cu. ft. to cool.
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Old 06-18-2015, 03:25 PM   #5
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Am surprised that a 13,500 was installed in a 34 footer as the main A/C instead of a 15,000. That may be a dometic penquin (low profile) high capacity 13,500. If is is, I would think about moving the 13,500 unit to the bedroom and putting a new 15,000 in as the main A/C. If you go with a dometic 15, it will not be a low profile, so check your roof location to see how your overall height is affected.
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Old 06-18-2015, 04:09 PM   #6
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Thanks for the good feedback so far :-)

Something we did to address the cooling issue was to hang blackout curtains over all the windows in the RV. They have grommets at the top and are hung on regular curtain rods so they can be easily opened when light is needed but really help keep the baking hot sun from coming in the windows when they are closed, plus they help block out light in the evening when we're sleeping.

We took down all the original window treatments, including the day/night shades and put up regular curtain rods and the blackout curtains in their place. The curtains are a nice light beige/vanilla color. I always imagine black curtains when I say "blackout curtains".

Most of the day/night shades were attached to the factory installed wrap-around valances so they came down when the valances came down. However, we've hung on to the day/night shades and may mount them just above the windows (still under the new curtains) for added insulation and light control.

Another thing we've done to combat the intense heat is to cover all the overhead vents with a custom-fitted foam padding that is dark gray (comes in squares that look like puzzle pieces and can be found at Home Depot, etc. Original use is for padded floor covering in garage, etc.) This also blocks the hot sun rays from baking overhead and further helps keep the space dark at night for sleeping. They are easily removed if we desire to open the vents. This is a temporary fix until we acquire some actual vent cushions which should offer even better insulation.

However, we know there is a second A/C install in our future regardless of these attempts at better temperature control. Hubby contemplates having a 15,000 BTU installed where the 13,500 BTU currently is and having the 13,500 BTU unit moved to the front bedroom where it's prewired for a second A/C. It seems like the bigger unit should be in the main area since it's taller and larger than the bedroom. However, that's all in theory at this point as we know it will most likely be costly to do. So, that's going to just hang out on the "future to-do-list" for now.

It's amazing what all you can learn about your new 5er in just the first 24 hours of staying inside it and I'm sure we have tons more to learn! We are loving our new 5er though and can see living in it fulltime at some point in the future.

We're open to suggestions from others who've solved similar issues before us. It's a brand new 2015 5er but we've already removed the booth dinette and the fold-out sleeper sofa. We've replaced the sofa with 2 comfortable swivel, rocking recliner chairs and we're looking for the right multipurpose idea for a table/desk/kitchen workspace to put between the recliners since countertop is lacking in most bunkhouse models.

We've got remodel ideas for the bunkroom as well. It will all take time, patience, and money to accomplish but it's fun dreaming about the completed project and traveling in an RV that's customized to feel like "home"...

So far, we've been able to use things we already had on hand in our S&B to customize the RV...and will look for bargains and finds along the way.
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Old 06-18-2015, 05:41 PM   #7
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I will never be hot again! 3 @ 15K

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Old 06-18-2015, 06:25 PM   #8
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We had one of our new a/c units go out a few months ago on our first trip out. We were parked in a shady spot and it was only 92 deg. There was no way 1 a/c could keep it comfortable inside. You need the second a\c for sure.
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Old 06-18-2015, 08:32 PM   #9
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We have no need for three AC's. Two 15K AC's keep us comfortable, even on 100+ degree Texas summer days.
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Old 06-18-2015, 08:42 PM   #10
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Our 30' Cougar FW with one AC and in FL was okay. Our 38' Wildcat FW with one AC couldn't cut it. Had to add a second.
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Old 06-18-2015, 09:10 PM   #11
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Originally Posted by drfife View Post
We have no need for three AC's. Two 15K AC's keep us comfortable, even on 100+ degree Texas summer days.
X2 ... Without thinking, I was driving alone on my Texas route from south Texas to north Texas I was only using the front console a/c to keep myself cool while driving (a 400 mile leg). What a mistake that was. The minute I pulled into my camp site and hook up I noticed the rest of the bus was at 96 degrees. I'm glad I have two rooftop a/c's (I might even upgrade them to bigger units), even if they ran for a long time to cool the place. The heat and humidity is bad during the summer here.

You need at least two a/c's.
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Old 06-18-2015, 09:24 PM   #12
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Our 40' Dutch Star had two 13.5 heat pumps, dual pane windows and an (at the time) optional roof insulation package plus Newmar was known for being one of the best insulated units made. In high 90 temps in Yuma we got by just fine with only one running.
But with most RV's you'll need more cooling than that and even better is to be in a shaded spot.
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Old 06-18-2015, 09:26 PM   #13
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Anyone traveling in the Deep South or the desert southwest really needs a second air conditioning unit--preferably ducted a/c.

You can add a second unit in a bedroom that's not ducted, however it's going to be very cold--and possibly very hot in the living room/kitchen. It's best if each unit has their own thermostat, and ducted to the whole trailer.

My new fifth wheel has only one a/c unit. We're trying to camp in tree'd campsites this Summer. Hopefully we can get a Dometic Penguin II installed over the winter.
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Old 06-18-2015, 09:48 PM   #14
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Window awnings help a lot.
Slides have little to no roof insulation.
Slide toppers help some.
One AC unit is not enough for 100+ degree weather, unless a small RV.
Shade trees are a very good thing.

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