Understanding Your Caravan’s Heating Cooling Systems

Caravans are essentially thin-walled boxes with large windows. They absorb heat like an oven in summer and lose it rapidly in winter. Managing temperature is one of the biggest comfort challenges of caravan living, and the solution depends on where you travel, when you travel, and how much power you have available.

Cooling Options

Roof-Mounted Air Conditioner

The most effective cooling solution. A reverse-cycle unit mounted on the roof provides both cooling and heating. Draws 1,500 to 2,500W, which means it requires 240V mains power (at a powered site) or a very large battery system with an inverter. Cannot practically run off standard battery setups for extended periods. The Dometic Harrier Inverter ($2,500 to $3,200) is the most popular aftermarket unit, known for quiet operation and efficiency. The Truma Aventa Comfort ($2,800 to $3,500) is another premium choice. The Houghton Belaire ($1,200 to $1,800) is the most common factory-fitted unit but noisier and less efficient than the Dometic or Truma.

12V Fans

Low-power ceiling or wall-mounted fans that circulate air inside the van. Draw 1 to 3A, making them easily sustainable on battery power. They don’t cool the air; they move it, which creates a breeze and makes temperatures feel several degrees lower. Essential for off-grid camping. The Sirocco II ($120 to $160) is the gold standard for caravan use: quiet, efficient, multispeed, and mounts on walls or ceilings with a gimbal bracket. The Caframo Bora ($80 to $100) is a solid budget alternative.

Ventilation

Roof hatches draw hot air out of the van and pull cooler air in through windows and vents. The MaxxFan Deluxe ($400 to $550) is the most popular powered roof vent: it has a built-in rain sensor, 10 speed settings, and can run while driving or in rain. The Fiamma Turbo Vent ($150 to $250) is a more affordable alternative. A powered roof vent draws 1 to 3A and makes a significant difference in hot conditions. Open windows with insect screens allow cross-ventilation. Combined with fans, good ventilation can keep a van tolerable in all but the hottest conditions.

Shade & Insulation

Awnings, reflective window covers, and shade sails reduce heat gain dramatically. Parking in shade (when possible) is the simplest and most effective cooling strategy. Reflective window covers can reduce interior temperatures by 5 to 10°C.

Heating Options

Reverse-Cycle Air Conditioner (Heat Mode)

Your roof-mounted air con can heat as well as cool. Effective down to about 5°C outside temperature, below which most units struggle. Requires 240V power. Common at caravan parks but not viable off-grid without substantial battery capacity.

Diesel Heater

The off-grid heating solution of choice. Burns a small amount of diesel to produce hot air blown through ducting into the van. Uses 0.1 to 0.3 litres of diesel per hour and draws 1 to 3A from the 12V system. Works in any conditions, any temperature, with no mains power required. The Webasto Air Top 2000 STC ($2,500 to $3,500 installed) and Eberspächer Airtronic ($2,000 to $3,000 installed) are the premium European brands with proven reliability. Chinese-made units from Belief and Hcalory ($200 to $500) are dramatically cheaper and increasingly popular, though build quality and longevity are less proven. A quality diesel heater is arguably the single most important upgrade for winter travel.

Gas Heater

Less common in modern caravans but still found in some. Burns LPG for heat. Effective but uses gas quickly and requires good ventilation (gas combustion produces moisture and CO2). Catalytic gas heaters are unflued (exhaust stays in the van) and require constant ventilation. Flued gas heaters vent externally and are safer.

Electric Heaters

Portable or built-in 240V heaters. Only work at powered sites. Fine as a supplement but not a primary heating solution for Big Lap travel.

What Do You Need?

Summer-only travel: Air con at powered sites, 12V fans and ventilation off-grid, reflective window covers.

Year-round travel: Air con for powered sites plus a diesel heater for off-grid winter warmth. 12V fans for summer off-grid. This combination covers every scenario Australia throws at you.

Budget setup: 12V fans, good ventilation, and a portable electric heater for powered sites. Works for mild climates and shoulder seasons.