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Getaways · 03-06-2012, 11:09 AM

Not sure where to post this thread...thinking this might be the best place.
I've looked through several "searches" to find the answer to my question but didn't find an close enough match.

As we are winding down our search for our airstream. We are really liking the layout of the 20' Safari SEs. Great kitchen counter top space, pano windows in the bedroom...

Prefer to save some $$$ and buy used. My question is on several of the units we've checked out they have an 11,000 BTU A/C in the 20 footers.

What is the performance in a 20 footer with an 11K BTU A/C? It gets hot and humid in the summers in southeastern VA. We're not yet retired and will be using it a lot on weekends so we can't go all that far to get to cooler ground (though the BLue Ridge Mountains are within easy reach). But, we still want to enjoy the beaches too. I am concerned that 11K is a bit small for our area in a camper that size.

Would love some first hand experience feedback. Thanks in advance for any insight.

TouringDan · 03-06-2012, 11:27 AM

Good luck in your Airstream search. I think that you are wise in looking at a variety of them and settling on a floor plan that works for you.

I don't have any true experience for you, but do have some engineering logic as food for thought. I think that most ac units are 13k btu/hr with the largest ac unit being 15k btu/hr. Folks usually recommend the 15k unit for hot climates. If you have a 15k unit for a 30 ft stream, this is equivalent to about a 10k unit for a 20 ft stream. I would think that you would be fine with an 11k unit. You can always upgrade the unit later if you feel the need. I would not think that this would be the primary factor in the decision on a used stream also. I would also switch to led lights for the interior, to reduce the heat load. They generate about 10% of the heat compared to regular bulbs.

BTW, one of our favorite campgrounds on the Outer Banks is Sands of Time in Avon. Check it out some weekend after you get your stream.

Good luck in your search.

Dan

Ag&Au · 03-06-2012, 11:36 AM

If you want to do a proportion comparison, we regularly take our 31 foot trailer to eastern Iowa near the Mississippi. Where we camp has no shade. The temperatures have been in the 90's with humidity also in the 90's. We have no problem with our 15,000 BTU unit. Since you have two thirds the volume to cool, I believe you would do fine. 11,000 is more than 2/3 of 15,000.

Ken

After I posted this, I realized that I said the same thing as the above post.
So it is 2 to 0 so far.

Ken

Getaways · 03-06-2012, 11:39 AM

Thanks Dan & Ken.

You are very insightful sirs. The size A/C unit will not be the deciding factor. But the idea crossed my mind and my natural curiosity wanted to look into it.

We stayed in a rental AS in VA Beach in Sept when it was still hot and humid. It was a 25' unit and I assume the standard size of 13.5K BTU. The unit seemed to really run hard and I felt struggled to keep the trailer cool during the heat of the day. 20' is 80% of 25' and 11K BTU is 81% of 13.5K BTU. So I thought the comparison made sense to question the ability of the 11K unit. Granted, being a rental unit in that area, I know that A/C may well have been run into the ground. But that is my only experience in an AS. Hence my search.

But as you said, the size A/C unit won't be the deciding factor. Again. Thanks.

Dan, you headed up to Sherando Lake any this year?

Ag&Au · 03-06-2012, 11:47 AM

There are some tricks to running the A/C.
If it will be working hard, it needs to be on high cool with the fan set to run on high continuously.
Ken

Phoenix · 03-06-2012, 11:56 AM

We have a 19-foot Bambi with the 11,000 BTU air conditioner, and it has no trouble cooling down the inside on 110+ degree days, mid-day, in the direct sun. However, the humidity in Arizona is usually very low compared to Virginia. With that caveat, the air conditioner cycles on and off, and we never set the thermostat to max; so it has more cooling capacity than we normally need, even during monsoon season when humidity is much higher.

Before you buy, you should test all appliances anyway; so make sure to include running the air conditioner, too.

Getaways · 03-06-2012, 12:05 PM

Update.

I just found out from a dealer that the KOA Option package includes an A/C unit from another manufacturer that delivers poorer performance. Additionally, and I should have caught this, the unit I was in has a lot more windows and therefore more heat penetration. And a wider body so more volume.....

SilverRanger · 03-06-2012, 01:42 PM

We have the 13,500 BTU AC/Heat Pump in our 19' Bambi. While in Perry, GA, (103 degrees F outside, no shade) we turned on the AC to run continuously, and left for about 60 minutes. When we came back, it was 67 degrees F. We kicked it up to 70, and set the fan to low, and it did just fine. I can't imagine an 11,000 BTU in a 20 footer not being more than enough.

BTW, great advice from w7ts:
"If it will be working hard, it needs to be on high cool with the fan set to run on high continuously"

xrvr · 03-06-2012, 01:52 PM

And I think an 1100btu unit will run off a single 2000 honda genny. jim

Foiled Again · 03-06-2012, 02:06 PM

Should be fine with 11K and a 20 footer. One thing that SHOULD be obvious is that there are intake screens in the AC unit that clog up with dust. I vacuum mine out at least twice a month. I did forget once - and wondered if my A/C was going bad... then I looked up and realized I had encrusted white lint in the vents. I could feel the temp. drop as I cleaned the filters. Your rental unit - at KOA - probably had never had the lint cleaned out of the filters.

(Try this trick on your hair drier and on your space heater if it has a fan. The gunk that comes out - yikes!)

Paula

Phoenix · 03-06-2012, 02:28 PM

Our experience has been that the 11000 BTU unit needs two Honda 2000s...

mefly2 · 03-06-2012, 04:56 PM

Current FC20 is 13,500 btu heatpump (all the way up to FC25FB); we need to EU2000 gens to start them up ... then same spec one throttles back on eco mode.

ROBERTSUNRUS · 03-06-2012, 10:15 PM

Hi, our 25' Safari has the 11,000 BTU air conditioner and it cools our trailer just fine. What helps mine is the fact that we have the small windows, mouse fur walls, and a vinyl headliner. A single Honda 2000 isn't enough, but our Yamaha 2400 works fine.

Skater · 03-07-2012, 05:21 AM

The 19' B190 had an 11,000 BTU air conditioner. Never had a problem, even at the Outer Banks in August. And those weren't all that well insulated, either.

AirsDream · 03-07-2012, 07:39 AM

Three points, more or less echoing what others have said:

1. I've got a 23 footer with mouse fur and vinyl interior, and an 11k A/C unit. It works just fine UNLESS the coach is parked in full sun and it's >90 outside air temp. Then it won't get it cold, but only comfortable. Moral: park in shaded areas when it's hot out, if you can.

2. The 11k unit runs fine on a Yamaha 2400 genset.

3. Since getting a solar power system, I've stopped carrying the Yamaha, and find that with a Fantastic Vent and a Fantastic Fan running inside, I can be pretty comfortable up to about 95 outside air temp and no A/C at all. But obviously there are a lot of variables, such as degree of shade, humidity, what you're wearing, your personal heat tolerance, etc. YMMV

ROBERTSUNRUS · 03-07-2012, 09:14 PM

Hi, I haven't read anywhere about it, but the solar panels should also help with external heat by shading parts of the roof.

slowmover · 03-08-2012, 10:48 AM

Humidity is the killer. I'm not sure I've ever seen anyone complain about too much A/C capacity, just the reverse.

Have a look at how you're using it (number of nights of use and climate/terrain), first, and spend time on window & vent coverings/insulation for same to cut solar gain (as these are good year round).

An inexpensive temp/humidity gauge is invaluable. Where I live (for homes) we read the humidity percentage as the first and last indicator of HVAC performance. 73F may be easy, but not with creeping humidity problems. Getting humidity down to around 45% is the real trick.

In this trailer I use a portable dehumidifier as the "bridge" between heat or cool appliances (as well as an oscillating table fan) to try and keep "comfort" affordable.

In the desert a slightly different approach applies.

Phoenix · 03-08-2012, 11:12 AM

Very true... I have been in 68 degrees and felt hot with humidity at 90%, and 80+ degrees at 5% humidity and felt cool. Fortunately, in Arizona, we only have to worry about humidity during monsoon season (late July through September), when the rains and dust storms come. However, our summer electric bills (for our home) are a killer, usually several hundred dollars a month.

CloudDancing · 03-08-2012, 01:53 PM

In August temperatures, we camped in Florida, South Carolina and Ohio. We had no issues with cooling our 20 foot Flying Cloud with the standard 11K unit. The 20 foot Airstream is a great choice!
L & K

TouringDan · 03-08-2012, 07:01 PM

Quote:

Originally Posted by AirsDream

3. Since getting a solar power system, I've stopped carrying the Yamaha, and find that with a Fantastic Vent and a Fantastic Fan running inside, I can be pretty comfortable up to about 95 outside air temp and no A/C at all. But obviously there are a lot of variables, such as degree of shade, humidity, what you're wearing, your personal heat tolerance, etc. YMMV

Airsdream

I go to a lot of music/bluegrass festivals in the summer and boondock, so my goal is to remain reasonable cool using fans only along with changing out all my interior lights to LED type. I plan to install some Fantasic vents along with two more 6v golf cart batteries so make sure that I have enough battery power to run the fans and minimize the amount that I need to run my 1 kw Honda generator. I have solar plans as well but this will come later.

Dan