Running a Caravan Air Conditioner from a GeneratorCaravan & Camping Products , Caravan Air Conditioners
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 (from the likes of Enerdrive) 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.
As mentioned earlier, most caravan air conditioner models will need somewhere between 2000 – 3000 watts to start. So, in order to get the right sized generator, you need to find out how much power your particular caravan air conditioner requires when starting up. Often this is not available on the product data plate or in the product manual (usually only the continuous running power is stated), so it is recommended you contact the manufacturer of your caravan air conditioner and ask them what size generator you would need to comfortably run that model.
An extra note here on this though; thankfully some of the newer Caravan Aircon models from the likes of Dometic are incorporating inverter technology into the Airconditioning unit which significantly reduces start up power requirements – we’re talking about the Dometic Harrier and Dometic Ibis 4 Aircon models. These new Aircons will comfortably start and run from a 2000w inverter generator. Most older Caravan Aircon units will still require a minimum of 2400w generator as mentioned above.
To help you select a generator to run your caravan air conditioner, we have created a guide:
Other factors to consider in running a caravan air conditioner from a generator?
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 two excepts 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.
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 already one of the most popular models on the market!
Recap and Generator Recommendations
In order to get the right generator to run your caravan air conditioner, best practice is to contact the air con manufacturer and find out what is the recommended size generator for your particular make and model of air con. Keep in mind that you may want to have some extra power capacity up your sleeve to account for external environmental factors and for running other smaller appliances.
The Yamaha EF2400iS is the most popular generator to run caravan air conditioners. It will start and run most caravan air conditioner models on the market, and it was awarded the number 1 caravan generator by Caravan & Motorhome on Tour Magazine in their mega caravan generator test.
Other popular models include the Cromtech Outback 2400w, the Yamaha EF2800i, the Yamaha EF3000iSE, the Briggs & Stratton P3000i, and the Dometic TEC29 built-in generator. The latter 4 models being the choice for people running larger air con models and/or wanting a bit more power.
A smaller percentage of caravan owners can get away with a 2000 watt generator. Again, the newly released Harrier Inverter Air Conditioner model runs comfortably from a 2000 watt generator, but while a few other models may do also, issues can often arise in hotter temperatures or when you need to run other appliances as well, or possibly also have your battery system hooked up. As mentioned, its always better to have a bit of extra power up your sleeve rather than get teeter on the edge and risk not having enough power in certain situations. If you don’t want to move to a 2400W generator then we highly recommend the brand new Yamaha 2200w Inverter Generator. This model comes with a boost feature for additional power, super quiet operation and has 10.5 hours run time – this is a whole hour longer than any of its competitors.
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 Honda, Yamaha, Briggs & Stratton, Dometic 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, 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.