If you're looking at installing a caravan air conditioner for the first time, there are a few things you need to consider:

1. Cooling capacity
   1. Measured in kilowatts – gives you the power output of the cooling unit. Common sizes are from 2.0 to 3.2 kW
   2. Sizing the air conditioner appropriately for the size of the van is critical in obtaining effective cooling.
2. Heating capacity
   1. Measured in kilowatts or BTUs – the power output of the cooling unit. Common sizes are from 1.0 to 3.2 kW
3. Heating type
   1. Most caravan air conditioners have built-in heaters – but some are electrical element heaters, and some are full reverse cycle units. 
   2. Reverse-cycle units use the compressor to heat the van, and are much more effective and efficient than element type heaters (which are simlar to a common blow heater)
4. Mounting – roof or split system
   1. Roof-Mounted
      1. Roof mounted units are simple to install, and don't take up any cupboard space. You just need to ensure you have enough head height to walk under the internal plenum.
      2. Some van roofs won't be able to support the weight necessary – e.g. pop-top roofs commonly are not strong enough for a roof top caravan air conditioner.
   2. Split systems
      1. Mounted in a cupboard inside the van – they take up cupboard space
      2. Generally, they are quieter than roof mounted units
5. Profile
   1. Roof mounted units come in a variety of heights. 
   2. Modern high quality units like the AirCommand Ibis is the lowest profile – which helps with clearances into garage 
6. Generator power
   1. Quite often you may want to run your caravan air conditioner when away from a powered site. In this case you need a generator, as attempting to run off large batteries / solar systems are simply not economical. 
   2. Common generator sizes are 2.0 and 2.4kVa, which are suitable for a large range of caravan air conditioners.
   3. Many caravan air conditioner manufacturers recommend 2.8kVa+, but most owners get away with smaller generators without issue. The main issue is that a 2.4kVa generator is easy to handle as a one-man job, any larger and they get too heavy to easily move around.
7. Features
   1. Remote control
   2. Wired remote (wall mount)