There are times of the year and parts of this great country that can experience either extreme heat, or chillingly low temperatures... So, when travelling around Australia in a Caravan/Motorhome, a caravan air conditioner can come in very handy to keep your van nice and comfy inside. When you enjoy the benefits of free camping away from a caravan park and mains power, you'll likely need to run your caravan air conditioner from a portable generator. So here is what you need to know:
Even though a caravan air conditioner is a fantastic addition to your vehicle, it will also likely be the most energy consuming appliance on your trip. An average caravan A/C unit consumes between 1000 to 2000 watts when running continuously and when it first starts up can consume between 2000 to 3000 watts to get the compressor going. As a point of reference, compare that to around 100-200 watts for your laptop, 50-100 watts for your fridge, and 40-50 watts for a fan.
There are less common examples of campers using their lithium battery packs, plus inverter & charger set ups (battery bundles can be found here) to run their caravan air conditioner...whilst this might suit the minority of RV'ers, it can be expensive and for many set ups it can be uneconomical, draining your batteries very quickly! So the most common way to run your caravan air conditioner in the absence of mains power is via a generator.
What Type Of Generator?
This part is easy - you'll need an inverter generator. Inverter generators produce 'pure sine wave' power, meaning it is clean power that is suitable to run your sensitive electronic equipment. Because caravan air conditioners have electronic componentry, you need a clean power source which is provided by inverter generators.
Additionally, inverter generators are more fuel efficient than other types of generators as they are able to idle up and down based on the load of the appliance. Lastly, you'll notice that most inverter generators have a 'suitcase' style design, meaning they are enclosed with soundproofing material making them very quiet so you don't disturb your peaceful campsite!
What Size Generator?
The answer to this is a little less straightforward, but we'll try to make it easy for you. There's just a few things you need to consider based on your particular make and model of caravan air conditioner and your particular situation.
Generators are rated by their maximum power output. So, a 2000 watt generator can produce a maximum of 2000 watts at peak, and will run at around 1600 watts continuously. Due to their size and weight, a lot of people want to use a 2000 watt generator, but unfortunately in many cases, this may not be enough power to start a caravan air conditioner.
Traditional non-inverter style air conditioners tend to have a high startup current and depending on the size of the compressor, may require a generator with a peak output higher than 2000W.
The 3 inverter style air conditioners from Dometic can be run by a good quality 2000W generator.
To save everyone the hassle of calling manufacturers, we have put together a table based on our extensive market research which recommends a suitable generator that we sell to run most caravan air conditioners that have been sold in Australia.
If your air conditioner is not on this table, please give a call and we will do our bet to size one for you!
Other Factors To Consider?
With all of this in mind, there are a few more things to take into account when looking at a generator to run your caravan air conditioner:
Temperature: As the ambient temperature and/or humidity increases, the power required to start the air conditioner compressor is greater and the power output of a generator decreases. This means unfortunately at the time when you need more power to start the compressor, the generator is actually making less power than it is rated at due to the higher ambient temperature and humidity.
The hotter the ambient air is (the air that is sucked into the engine for combustion) the power output of the engine and generator will decrease. A good rule is to allow a 1.5% decrease in output for every 5 degree C above 25C. So on a 45 C day, a genset will be de-rated by 4 x 1.5 = 6%. Height above sea level will also cause then genset to be de-rated further.
Extension Leads: It is also suggested that a short lead from the generator into the van (no longer than 3-4 meters) is used in very hot conditions, as there is amperage drop over longer leads.
Other appliances: you will also need to bear in mind the load drawn by other appliances running at the same time as your caravan air conditioner: Battery charger, fridge, lights, TV etc. Often we find that customers who are running an air-conditioner on a generator that is only just enough to handle the air con start up requirement, will have troubles if their battery charger is plugged in at the same time for example.
So, overall, these are other considerations when selecting the right generator for your caravan, and highlights that opting for a genset with a bit of extra capacity beyond the peak draw of your air conditioner is a good idea.
Any Exceptions To the Rule?
Yes. There are six excepttions to the rule that we know of. In mid 2016, Dometic released the Harrier Inverter Air Conditioner: featuring the first use of an inverter compressor in an RV application. This means the Dometic Harrier Inverter can help eliminate start-up current issues when running from generators or when current supply is restricted. Where most other caravan air conditioners will require more than 2000 watts at start up, the Harrier can comfortably start and run from a 2000 watt generator such as the Yamaha 2000W Inverter Generator. (It is important to note, the Harrier has now been superseded by the Harrier Plus Air Conditioner).
In 2019, Dometic released the Ibis 4 Reverse Cycle Rooftop Air Conditioner, which improved the many industry-leading features of the Ibis 3 and incorporated them into a new light weight roof top design. Like the Harrier, the Ibis 4 uses inverter technology to eliminate start-up current issues and can be run from a 2000 watt generator. But the Ibis 4 features an industry first - it features a dual-cylinder horizontal compressor. This compressor reduces vibration in the a/c unit which reduces noise - a major benefit in most customer's books!
The Ibis 4 features impressive cooling, quiet operation and an ultra sleek low profile design - no wonder it is one of the most popular models on the market!
Also in 2019, Dometic released a lite version of the Harrier, targeted at mid-sized RV owners. The Dometic Harrier Lite Roof Top Air Conditioner weighs in at 36kg, and is the most efficient of the three Dometic inverter air cons on the market. The Harrier Lite is perfect for cooling vans up to 6m in length.
New to the market in 2023 Dometic have released their impressive FreshJet 7 Series models. These have been designed with the off-gridder in mind making them even more efficient than the Harrier and IBIS models. The FreshJet 7 Series lite, the Pro and the Plus will fast become the number one choice in rooftop air cons especially for use with a generator.
Recap and Generator Recommendations
Our air conditioner sizing table is the best resource to help you in your quest to find a quality generator to run your caravan air conditioner. Just bare in mind that the generators are recommended from the minimum requirement, therefore don't be afraid to choose a slightly larger model to take into account running other appliances and other external environmental factors.
The Yamaha EF2200IS is the most popular generator to run caravan air conditioners. It will start and run most caravan air conditioner models on the market, due to being lightweight, efficient and the boost feature!
Other popular models include the Cromtech Outback 2400w, the Yamaha 2400IS, the Briggs & Stratton 2400W, the Engel 2500W, the Briggs & Stratton P3400, and the Dometic TEC29 built-in generator. The latter 3 models being the choice for people running larger air con models and/or wanting a bit more power.
When you are choosing a generator for your caravan, it is recommended you opt for a quality brand that has comprehensive warranty coverage along with national service agent and spare parts support. Premium Brands such as Yamaha, Briggs & Stratton, Engel etc. have hundreds of service agents around the country meaning that if you ever need the genset inspected under warranty, serviced or require spare parts, then you are covered.
Even a select number of budget brand generators, such as Cromtech or Maxwatt, have national service agent support. They are made in China, and the premium brand units might be slightly superior in terms of specs, but their price is compelling and you still get national service agent backing.
It is not recommended you choose a cheap no-name generator (often sold on places like eBay) that do not have national service agent support. We repeatedly get stories of these cheap brands not honoring warranty, or when something goes wrong with the generator on the road, then there are long and frustrating delays to the caravan trip as there is no service agent or spare parts support.
To find out more about generators to run Caravan Air Conditioner units, check out our range HERE.
DISCLAIMER* Please note, this advice is general in nature and we strongly recommend consulting the product manual and where relevant, a professional installer.