AIR CONDITIONING

Air conditioning your Trailer is another one of those undertakings that should be planned, rather than an after thought.  With Home Builds I have seen a variety of installations.  In the RV world, products have developed through the years for a reason to get to where they are at the present.  But some are successfully outfitting their trailers with less expensive units.

Traditional RV Industry standard roof top Air Condition units
(Typically the 13,550 BTU, or 15,000 BTU units.
Require 110VAC to operate.  Most require at a minimum a dedicated 15amp or 20amp circuit.
Normally installed on #12 Copper AWG
Most require at a minimum a 3000 watt generator to run them
Advantages are ease of installation in a standard roof cut out where power is wired.
Some state they operate without damage on fluctuating power found at some ill maintained campgrounds.
At around the 100lb range these units do require adequate reinforced support.
They are roof mounted and blow the air at ceiling level.

Standard Window Air Conditioning Units
A variety of BTU ratings which gives you flexibility at matching your trailer size and climate
Require 110VAC to operate.  Most require at a minimum a dedicated 15amp or 20amp circuit.
Some might be able to operate on generators less than 3000 watts
In some trailers they can be mounted in a window without modification
Some are installing them permanent through the wall with the addition of condensation catch/drain pans
Wall mounted verses Ceiling mounted might be preferred by some?

Split System Air Conditioning Units  (Some also provide Heat)
9,000 BTU,  12,000 BTU, or 18,000 BTU units.
Require 110VAC to operate.  Most require at a minimum a dedicated 20amp circuit.
Requires #12-#10 Copper AWG depending on unit
Compressor/Condensing Unit on the outside - Evaporator/Blower on the inside
Some are installing the Compressor/Condenser unit outside on the trailer tongue
Some are installing the inside Evaporator/Blower near the front area at floor level
Similar in price to RV type unit when BTU rating is similar.

Portable roll around Air Conditioner Units
A variety of BTU ratings which gives you flexibility at matching your trailer size and climate
Require 110VAC to operate.  Most require at a minimum a dedicated 15amp or 20amp circuit.
Most are doing temporary set ups with these once they get to camp.
Most have an intake and output port that require some type of "ducting" such as flexible dryer vents
These units can't be run while inside unless air is ducted into the unit, and a condensation drain is made
Most of these I have seen a rather tacky looking. 
While they may do the job expect some parks to give you a hard time, or ask you to leave.

Can I run my Air Conditioner with an Inverter running off my battery?
While the general rule is you will have to have 110VAC available to run an air conditioning unit I have had some state they have operated off Batteries using Inverters.  While this may be true, the math doesn't support those statements.  At least not without throwing lots of money at it.  More than you would care to invest to use such a setup while camping. 

Sure....maybe!  If you want to get technical.  But for general rule of thumb, no way.  If you had a ton of battery storage, an adequate  inverter to handle the start up and run, and perhaps a very small (Low BTU rated) air conditioner, run for a short time.  Yes I would say it is not impossible.   But expect to invest a lot of money.  For the most part it is not feasible.