Campervan AC units

[OnNTwo]

I live in Texas and I've noticed that some van manufacturers install from 11000 to 20000 BTU units in a 21 foot van. It made me wonder if the 11000 BTU unit could handle a Texas summer. Has anyone had experience with a 11000 btu van in a very hot state?

[avanti]

Originally Posted by OnNTwo

I live in Texas and I've noticed that some van manufacturers install from 11000 to 20000 BTU units in a 21 foot van. It made me wonder if the 11000 BTU unit could handle a Texas summer. Has anyone had experience with a 11000 btu van in a very hot state?

It's a tradeoff. If you want to go from tropical to frigid in 5 minutes, you need a large A/C. OTOH, if you care more about humidity than temperature (and IMO you should), a smaller unit will have longer duty cycles and thus will work better as a dehumidifier. In a perfect world, the ideally sized A/C would just barely run continuously at the desired target temperature. Of course, in a van with its limited insulation and widely-varying outdoor temperatures, you can't get near this ideal.

We have an 11K unit and have been happy, even when camping in Texas, but it does take awhile to cool down a very hot van. And naturally, insulation and vehicle color matter, too.

[rowiebowie]

Most never complain of their b's air conditioning capacity whether they have a 9K btu CoolCat or 13.5K roof ac.

That being said, I replaced a 13.5K roof unit with a 15K. Not too much a/c and I'm not sure there is such a thing. Also, the newer unit uses about an amp less than the smaller 8 year old unit it replaced. There are even some newer Coleman NDQ units that use a few amps less than my unit.

My conclusion is that a van is not a house, where an over-sized unit can cause problems by not running long enough to de-humidify. My bigger unit runs plenty and cycles very little in hot weather. Plus, it never "freezes out" the front cab area which is furthest from the a/c and the source of a lot of heat gain due to cab windows and windshield, even though we have the majority of airflow directed forward. Someone on this forum speculated that a typical dash a/c unit is in excess of 20Kbtu so maybe that explains it since it barely keeps the rear comfortable while driving.

I say go as big as you can, enjoy the cooling at no amperage draw penalty (compared to older units), and let the a/c thermostat cycle to your comfortable temperature.

[Rlum]

Originally Posted by OnNTwo

I live in Texas and I've noticed that some van manufacturers install from 11000 to 20000 BTU units in a 21 foot van. It made me wonder if the 11000 BTU unit could handle a Texas summer. Has anyone had experience with a 11000 btu van in a very hot state?

Staying cool in how weather is very difficult in a van. First I would try to avoid camping in these hot climates. May not be possible in Texas?
2nd the insulation of the van is very, very important. Poorly insulated vans with lots of window space and non reflective surfaces require a lot more AC.
3rd if you require lots of AC, you will probably use hook ups or run your generator a lot.
4th AC units generally generate lots of internal noise with their fan units. With AC running with generator, it is difficult to have a conversation.
About a yr ago, I switched our Dometic 11K to a Houghton Belaire 13.k unit. Much quieter! Still could not tolerated noise of generator so replaced with an inverter model. The heat and noise are now tolerable. I still do my best to avoid the hot camping climates as much as possible.

[jrobe]

Originally Posted by Rlum

Staying cool in how weather is very difficult in a van. First I would try to avoid camping in these hot climates. May not be possible in Texas?
2nd the insulation of the van is very, very important. Poorly insulated vans with lots of window space and non reflective surfaces require a lot more AC.
3rd if you require lots of AC, you will probably use hook ups or run your generator a lot.
4th AC units generally generate lots of internal noise with their fan units. With AC running with generator, it is difficult to have a conversation.
About a yr ago, I switched our Dometic 11K to a Houghton Belaire 13.k unit. Much quieter! Still could not tolerated noise of generator so replaced with an inverter model. The heat and noise are now tolerable. I still do my best to avoid the hot camping climates as much as possible.

I agree with all of this. We almost never use our AC because it is miserably loud. Most of the time we would rather be hot than listen to it. I don't think I could even sleep all night with it on without ear plugs. If I build another Class B someday I will either install one of the newer quieter models (like the Houghton) or I will just forget it and head further north. I would concentrate on the decibel level of the AC unit and not worry about the btu output.

[avanti]

I am going with an undermount 24VDC unit this time. Hopefully between that and a big battery instead of an Onan, it will be usable without earplugs.

[jrobe]

Another thought - these 12 volt fans are worth their weight in gold. There are many hot summer nights when these things have saved us from even considering AC even if we had shore power. They move a lot of air and are very quiet. Great design.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[OnNTwo]

All great points to consider. I hadn't thought about the dehumidifier features of an ac. Thanks for your posts.

[rowiebowie]

Originally Posted by jrobe

Another thought - these 12 volt fans are worth their weight in gold. There are many hot summer nights when these things have saved us from even considering AC even if we had shore power. They move a lot of air and are very quiet. Great design.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

+1 !

This little squirel-cage fan moves a lot of air for it's size without too much noise.

[TX-Trek]

We're in Texas with travels so far across the southwest - over a year ago I replaced our failing CoolCat with a residential style 12k btu window unit. Very quiet, cools very well in 90d weather and will cool off the parked van quickly. No complaints. We also sometimes use a small fan for additional air circulation when parked.
https://www.classbforum.com/forums/f...out-11478.html