HOT IN TEXAS!!!! Upgrade a 13,000 BTU to a 15,000 BTU? Does it help?

[Gavin]

I upgraded to 15,000btu about 18 months ago on 2005 Classic (home is Mississippi). We have appreciated a noticeable difference.

[NevadaGeo]

Originally Posted by jdalrymple

Our 27' gets warm with the one 13,500 unit, too.

We learned the following cheats help a bunch, all proven at Burning Man:

Go to Lowes or HD and buy some reflectix insulation and cut out covers for the roof vents and skylights. Use small velcro self-stick tabs to make them removable. The tabs are at Lowes too. In our trailer, the foil reflecix blends in with the shiny aluminum interior sheets.

Also cut reflectix "inserts" for the windows. One can place them between the window and the screen, from outside the trailer, or simply let the curtains hold them in place. Sandwiching them behind the windows works a little better, but requires a little more effort.

As mention before, use a fan(s) to help move the air.

Start EARLY. Accept being a little cool in the night or early morning in trade for being cooler during the heat of the day. Keeping a 75 degree trailer below 85 degrees is a whole lot easier than trying to cool a 90 degree trailer in 105 degree heat.

As for adding a second AC, a complete upgrade to 50 amp is not absolutely required. I have seen many AS trailers that simply added a second 20 amp shore line which powers only the second AC unit. One only plugs it into shore power when the second AC is needed.

We considered the second AC install, but have been satisfied with the solutions above.


Regards,

JD

Don't stop with the windows. Jeff, I don't know if you noticed on playa, but I have the reflectix stuff on my walls too as much as I can. Helps a lot, and in the winter too. I've seen playa sun heat the outside walls to over 140'sF on the Blue stripes, over 120F inside. With the reflectix it'll stay at less than 90. A good portable swamp cooler can do the job then but the humidity is less than 10% out there. I'd like to try the special white paint on the roof some time.

If you do have a separate power cable, do you have problems with voltage between the commons?

[HiHoAgRV]

I'll add onto the 20 degree comments- It's not so much 20 degrees from inside to outside, it's actually 20 degrees from the AC intake to the discharge. Straight from Colemans Owners manual-

"As a general rule, air entering the air conditioner will be
cooled about 15 to 20 degrees, depending on the outside
temperature and humidity conditions.
For example, if the air entering the return air grilles in the air
conditioner is 80 degrees F., the air leaving the discharge
grilles in the air conditioner will be 60 to 65 degrees F.
As long as this temperature difference is being maintained
between the return air and discharge air, the air conditioner is
operating at its capacity. If the desired inside temperature
(normally 80 degrees F) cannot be maintained, then the heat
gain of the RV is too great for the capacity of the air

conditioner."

I agree with all of the above suggestions to help cool off the interior, we broke down and added a second AC to the bedroom of our 34'.

[handn]

I think JD gives good advice to start cooling early and not expect the a.c. to cool a hot trailer to comfortable temps without a lot of running.
We have a 25 Safari with the 11,000 btu unit. We take the trailer from Tucson back to Colorado in the second week in June and all through Arizona and southern New Mexico it is usually in the 100's. When we take the trailer out of storage in the afternoon, it is blazing hot. We park the trailer put the ac on max and go to a cool place to hang out. After 4 hours or so when it is dark, the inside of the trailer is habitable. We keep the ac cranked down cold all night even though we sleep under a blanket and it would be tempting to open the windows. The next day we start out at 75 and in the afternoon the trailer is 85 but comfortable when it is 105+ outside. Tucson has low humidity in June.
We found we were comfortable in Florida in July because outside temps were in the low 90's and the a.c. did a good job of dehumidifying the air.
Our Safari has few small windows and they are glass except for the vents. Some models have lots of windows. For those I would get material like a windshield reflector and put tape it to the inside of the windows and vents. Nothing builds up heat faster than hot sun shining through plastic windows and vents.

[slowmover]

There are some other threads on this subject. 50A service upgrade and twin A/C units is what "works" for those for whom extended high heat (and/or high humidity) is experienced for extended periods.

What I've done is this:

1] Service the A/C you have. Not just an extra set of filters, but clean the condensor (aerosol coil cleaner) and evaporator. Waterproof covers for interior furnishings.

2] REFLECTIX for roof vents and windows is good, but with complementary fabric cover for interior side and charcoal for exterior (looks much nicer) and construct so as to be a interference fit on windows and industrial velcro for vents. Vents really do need a true exterior cover of their own, not just interior. One need not cover all windows, but some windows won't be used in high heat (such as behind front cover, etc; but it still needs insulation).

3] An oscillating table fan. Orient so that fan also pushes air BACK to A/C unit. Check seal around refrigerator, and oven exhaust fan vent and any exterior compartment doors (just need loose insulation to block off).

4] Afternoon shade. There is no substitute, in the end.

5] Don't turn off A/C. And don't turn down fan speed. It takes about 48-hours to completely cool down a TT that has been days in high heat. Open cabinets, etc.

6] Humidity control. A de-humidifier can take the load off an A/C unit on some days. I leave my A/C off on those days and run only the dehumidifier when I am gone. And then turn off, and turn on A/C. Takes very little time, relatively, to have cool dry air.

.

[litlgeezer]

One thing I did to assist in cutting down on the heat was to fabricate insulation pieces for the Vista windows out of 1/2 inch foam board. It's thin enough to allow the pull down shade to slide over it. The windows have some sort of deterioration between the panes, so there's not a big loss without those ugly windows open.

[perryg114]

There are some who have experimented with putting water misters on the roof. This would work really good in dry climates.

Perry

[Crusty]

Water misters work whenever the sun is shining on the roof. The heat from the sun is removed from the skin as steam which can even be seen with the right back lighting. Turning the misters on results in a 10-15º interior temperature drop within 30 minutes.

If you have hard water the stains left by the minerals in the water look ugly, but from my perspective of an all time hottest summer two years ago the stains were a secondary consideration.

[slowmover]

Originally Posted by Crusty

Water misters work whenever the sun is shining on the roof. The heat from the sun is removed from the skin as steam which can even be seen with the right back lighting. Turning the misters on results in a 10-15º interior temperature drop within 30 minutes.

If you have hard water the stains left by the minerals in the water look ugly, but from my perspective of an all time hottest summer two years ago the stains were a secondary consideration.

And there's bound to be some mild acid wash one could use in an electric pressure washer to take care of that come October.

It's an impressive temp drop (thanks for posting that info).

.

[perryg114]

Vinegar

[Crusty]

Dunno about any acid treatment because I didn't want to etch the aluminum. Most of the stain is gone now due to what little rain we've had here in Austin, so that makes me think that there's some kind of cleaner which will take it off. A properly prepared trailer might even have some sort of non-stick coating (wax?) applied before the mister was ever turned on to make the subsequent cleanup easier.

The temperature drop inside is dramatic enough to notice. The ceiling and walls stop radiating heat as soon is the water is valved on so it feels cooler in short order.

Shade is still the best overall solution.

[Landshark]

We've been living in our '86 34' LTD in College Station, TX, since mid-Aug last year and have survived quite comfortably with:

1) one new AC 15000 BTU and a fan in rear to circulate cooler air
2) reflectix on all bedroom windows, including rear wrap-around window
3) all awnings out (big awning secured with strap and HEAVY weights against wind)
4) shade trees almost against trailer on east
5) market umbrella to block westerly sun from doorway and front window below big awning (next-door trailer shades rest of ours)
6) as others have said, get a head start on cooling by running AC even early in the morning or all night as heat demands.

Everyone said we would need two AC units to cool this monster, but we didn't want to go to 50 amps, so we took a chance and it has worked fine with just the one unit; we're really enjoying Texas. Good luck!

Vivian

[texasbound]

Originally Posted by Landshark

We've been living in our '86 34' LTD in College Station, TX, since mid-Aug last year and have survived quite comfortably with:

1) one new AC 15000 BTU and a fan in rear to circulate cooler air
2) reflectix on all bedroom windows, including rear wrap-around window
3) all awnings out (big awning secured with strap and HEAVY weights against wind)
4) shade trees almost against trailer on east
5) market umbrella to block westerly sun from doorway and front window below big awning (next-door trailer shades rest of ours)
6) as others have said, get a head start on cooling by running AC even early in the morning or all night as heat demands.

Everyone said we would need two AC units to cool this monster, but we didn't want to go to 50 amps, so we took a chance and it has worked fine with just the one unit; we're really enjoying Texas. Good luck!

Vivian

Vivian,

Thanx for this! We are full timing in our 74 sovereign just outside Austin. Currently just have our original dometic, two fantastic fans, and reflectix.
Debating on plunking for a new 15k, or going with a portable 12k.............
Leo

[slowmover]

There are threads on the rollaround A/C units (if that is what is being considered) and IIRC, they are not up to the task. Remember that the default for one of these TT's in lengths of 27' and longer is 50A service and two roof units.

No one working the oilfield is comfortable w/o two units (mainly SOB's).

The summer temps here in Corpus are not as high as in Central Texas, but the humidity makes the heat index unbearable. That I am parked in full shade past noon is what makes it possible for me to maintain an acceptable temp with a single 15K unit (and a new MACH 8 Coleman is planned). Were I not planning to move north after another year I would already have sourced the pieces for the amperage upgrade already.

There is, literally, no such thing as too much A/C capacity in the hottest parts of the US. And no cooling at night to ameliorate high daytime temps. 98F at midnight is NOT uncommon in summer. Because this year is not nearly as hot as last year this late in spring . . well, just wait.

.

[KJRitchie]

Some of us are lucky enough to have the built it water mist feature on our Airstream AC. Turn on the AC and then stand underneath the air distribution box and let the water dripping out of the air distribution housing cool you off.

Kelvin

[Snaken49]

My first AS was a 2008 25' FB Safari with a 13,500 BTU AC. It took one afternoon in Palo Duro Canyon near Amarillo, TX at 108 degrees to convince me to upgrade to 15,500 unit. I had the work done at North Dallas RV and they did a first class job.

The upgrade coupled with the reflectix covers mentioned in previous posts installed on the windows made a tremendous difference, dropping the inside temp by 15-20 degrees. But even with the upgrade you still need an additional small fan(s) to move the cold air upfront or to the back as the case may be.

I eventually sold the 25' footer and upgraded to 2010 28' Safari with a stock 15,500 BTU AC. It has a rear bedroom with a big window where a headboard would be so I installed reflectix to reduce the heat. I also added a small fan that I clip on the closet door to push the cold air back into the bedroom. The system so far is keeping the inside at a cool 74-76 degrees when it is 104 outside with no shade.

I'm not sure if adding a second 15,500 unit or limitations of a 50 AMP electric system is worth the cost. However the upgrade from a 13,500 to 15,500 in the 25' footer was well worth it.

Stay safe and cool!

[StagrLee]

I just did a weekend at Lake LBJ in my 25' Eddie Bauer. 105 outside/93 inside temperature split at 3:00PM. Ended up closing the retractable curtains to the bath and bedroom which dropped the kitchen area to 85 which was quite nice. Great thread folks. Always like hearing about what works at Black Rock City.

Would love to see some pictures of the foil bubble wrap deployed on your rigs.

[Snaken49]

StagrLee

This is a pic of my back window showing the Reflectix installed between the glass and the screen.

You can purchase this at Lowes or Home Depot or almost any hardware store.

Hope this helps you to stay cool!



Shop Reflectix 25-ft x 24-in Reflective Insulation at Lowes.com

[StagrLee]

Originally Posted by Snaken49

You can purchase this at Lowes or Home Depot or almost any hardware store.

Hope this helps you to stay cool!



Shop Reflectix 25-ft x 24-in Reflective Insulation at Lowes.com

Nicely done. Like the price too. Are you sealing up the fantastic fans, overhead window and vestibule/vista windows?

[mansaj]

What are you using to hold the reflectix material in place?