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View Full Version : Realistic A/C performance??


Kristi
06-28-2013, 06:40 AM
I have a 30' passport and a 13,500 btu ducted a/c unit. I've read somewhere only to expect 15-20 degrees cooler in the TT then outside, sooo if it typically hits 100-105F here in the summer, am gonna be looking at 85 to 90 degres in the TT.

I realize shade, the awning, precooling in the am will factor into how well the a/c does, but I was hoping to hear from some of you guys who have similar setups and have camped in the heat. (tx)

TAZ23
06-28-2013, 07:36 AM
I have also found that keeping the shades closed will help somewhat in keeping the inside of the trailer cooler and more comfortable especially in bright sunlight. last year we Kept our Outback fairly comfortable in 95 degree heat. It made a differance of about 5 degrees closing the blinds. The windows are only single pane glass and have very little R-value. Also by limiting the number of times you open and close the door it will help.

86GT2r
06-28-2013, 07:52 AM
We have the same setup as you do. The temp was 105. F. When we visited the Badlands 2 years ago. We had a mostly shady site & didn't have any trouble keeping the inside comfortable. As others have stated, it helps to have your blinds closed.

JRTJH
06-28-2013, 08:03 AM
Way back when, we had a Holiday Rambler 34' travel trailer. It had a 15K A/C in the front and a 6K A/C in the back. When in Las Vegas in July, in Phoenix in August and in Blythe in August, the temps during the day were 110-120. We were parked in the sun and with both A/C's going "full bore" all we could do was keep the trailer a tad cooler than outside. Heaven forbid turning on a burner on the stove.

The efficiency of the units was such at at night you literally could "hang meat" in the trailer. It would easily cool into the 60's.

Nearly any RV that I've seen, with R-10 walls, R-15 ceiling and R-14 floors, single pane windows, air leaks around slides, open "holes" in the ceiling streaming in hot sunlight, and an occasional open door, the best you're going to do when sitting in the sun is to get maybe 20F below outside temps.

Try parking so the awning blocks the RV sidewall from sun, park in the shade, possibly, if you can, put a sprinkler hose on the roof to help with some evaporative cooling. But don't expect to be "calm, cool and collected at 75F in temps over 100F with a single A/C in a 30+ ft RV. You face another "issue" with trying to add a second A/C: That's the 30 Amp service. Unless you wire an additional line into the RV, say a 20Amp extension cord, or a similar type connection, you're not going to be able to run both A/C's and still maintian converter/refrigerator/interior lights.

Good luck.

f6bits
06-28-2013, 08:05 AM
If I was camping where it's routinely over 100°, I'd get a bunch of window reflective material:
http://www.homedepot.com/p/Reflectix-4-ft-x-25-ft-Double-Reflective-Insulation-BP48025/100052556

Kristi
06-28-2013, 09:11 AM
http://www.homedepot.com/p/R-Matte-Plus-3-R-5-0-3-4-in-4-ft-x-8-ft-Foam-Insulation-W-N5075X/100317820#.Uc3C5owo600

I cut a couple pieces of this to fit the roof vents/skylights also. Noticed a bunch of heat comes in through those even when they are closed.

Trent McCain
06-28-2013, 09:21 AM
We are in the KS heat for harvest. We have minimal trees in the campground. As others have stated keeping doors shut and blinds closed helps but on a 100+ degree day our inside temp is mid 80's. At night we have stayed fairly comfortable. Never really been an issue when we camped for a weekend. We have not stayed any extended time in our coach before this. I can say the next coach will be 4 seasons with a larger A/C. This one works for now, but with each adventure, we learn what we like and what we don't.

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SAABDOCTOR
06-28-2013, 09:41 AM
I finally gave up and put a second a/c unit on mine! i keep looking at that artic package sticker.I was hopping that since i wasn't any warmer in the cold months that maybe it saved the cold air to use in the summer.:D guess not:banghead: dang sticker!

Bob Landry
06-28-2013, 03:55 PM
The 20 degree difference between inside and outside is mentioned a lot on all of the forums, and it is as incorrect as ever. The 20 degree difference is what the temperature difference should be between the discharge and return air, also called the split across the coil. Outside temperature is irrelevant except to remind you of how hot a poorly insulated and under air conditioned trailer is going to be. That 20 degree spilt is also dependent on the unit being properly charged(most are) and that you don't have cold air leaking into the ceiling. Even with everything right, 13.5 BTU is not enough AC for a 30 ft trailer in a hot climate.
There are some things you can do to improve it. There are several threads on here about sealing ducts and ceiling plenums. With everything in proper order, a failure to achieve the 20 degree split indicates that there is not enough BTUs of air conditioning for the given space

Ken / Claudia
06-28-2013, 10:36 PM
At the Keystone new owners workshop I went to last month they said what Bob just said and added to help further start running the A/C early in the day. Thats all they had.

SAD
06-29-2013, 03:34 AM
RV Vent Pillow... Wont leave home without them.

http://www.uhlmannrv.com/uploads/image/Coupon%20Pics/VENT%20PILLOW.jpg

Reflectix on the upper side

http://www.byexample.com/library/photos/projects/winterizing/win_03664.jpg

They work GREAT!

All RVs are different (size, number of slides, # of A/C units)... as are all camping spots (relative to shade, breeze, etc)...

But generally when the outside air temps are 90-95-nearly 100 I can maintain 72-75.... When it jumps to 100-105-108 it'll be 77-78 inside.

One of my favorite campspots has a "whole" in the sky such that late afternoon, the living room slide gets baked.

Little Guy
06-29-2013, 06:40 AM
I was wondering if anyone has tried a portable AC unit that vents to the outside to supplement the main AC unit in the camper. I was thinking of running a heavy duty extension cord to the pedestal to power up the portable unit.

Kristi
06-29-2013, 06:47 AM
Sad, that's kinda what we made with the foam insulation sheets. The pillows look better though :)

Kristi
06-29-2013, 06:50 AM
It's gonna be unseasonably cool here this week 85-90 in July "bouncey: but I'm wishing we could just start migrating north for the summers! :)

Riverbound
06-29-2013, 07:07 AM
I was wondering if anyone has tried a portable AC unit that vents to the outside to supplement the main AC unit in the camper. I was thinking of running a heavy duty extension cord to the pedestal to power up the portable unit.

My buddy did that with his trailer. Worked as well as a two Ac deal.

Festus2
06-29-2013, 07:59 AM
We have an Uberhaus portable A/C that we use in our house on rare occasions when the temperature gets around 85+ degrees. It is rated at 8000 BTU's and would, I suspect, supplement a single A/C unit in a TT. This unit draws almost 9 amps and comes with remote. They can be obtained from most big box stores and won't break the bank. Good for small rooms and spaces.

The drawbacks as I see them are:
1) floor space would be taken up
2) needs to be vented (with fairly large hose/pipe) to the outside
3) requires a drain.
4) needs to be wired in or the use of a HD extension cord.

I suppose one could rig up a vent that wouldn't be too cumbersome, take up too much space, or get in the way.

In the long run, it might be just as easy and more convenient to have a roof-top A/C installed and make any necessary adjustments to your RV wiring to accommodate the unit.

Trent McCain
06-29-2013, 09:21 AM
I think if the AC quits, I'll upgrade to a larger one if possible. When we purchased this coach we didn't plan on living in it for any extended time. One of thing we tried last night was a small tower fan. It helped move the air and made things a little more comfortable. Its cooler today @ 93 and the inside temp is 75. Not quite as cool as we keep the sticks n bricks, but not uncomfortable.

Trent

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