Caravan Air Conditioning: How It Works

Jul 12, 2025

Ever opened your caravan door in summer and felt like you entered a pizza oven? Caravan and motorhome air conditioning saves the day by sucking out the heat and blowing in cool bliss.
Short answer? It uses a refrigerant cycle to chill the air.
Stick around to see how it all works!

The Core Principles of Caravan Cooling

It’s All About Heat Transfer: The Basic Concept

Caravan air conditioners cool by managing temperature and humidity. The key lies in transferring heat from inside the vehicle to the outside air.

This keeps the interior cooler and more comfortable for those long summer road trips.

Moving Heat from Inside to Outside

The system uses a refrigeration cycle to remove unwanted heat. A refrigerant absorbs the heat inside the caravan and moves it outdoors. This cycle works continuously while the air conditioner is running.

It’s a clever, enclosed process that lets you enjoy cool air while the system quietly shifts the heat elsewhere.

Why Dehumidifying is Just as Important as Cooling

Caravan air conditioners don’t only reduce temperature — they lower humidity too.
Removing moisture from the air helps the space feel cooler and less sticky.
High humidity can make even moderate temperatures feel oppressive, especially in small caravan spaces.

By drawing out both heat and moisture, the system creates a fresher and more comfortable environment.

Dometic roof-mounted air conditioner for motorhomes, on a white background.

The Key Components and Their Roles

Several essential parts work together to make caravan cooling possible.

The Compressor: The Heart of the System

The compressor pressurises the refrigerant and increases its temperature. This is where the cycle truly begins. It's considered the heart of the system because nothing moves without it.

A working compressor keeps the refrigerant flowing and the cooling process going.

The Condenser: Releasing the Heat

Once the refrigerant is compressed, it travels to the condenser coils. Here, the heat is released to the outside air. This turns the hot gas back into a cooler liquid.

Fans often assist in this process to help move the warm air away faster.

The Evaporator: Creating the Cold Air

Now a cool liquid, the refrigerant flows into the evaporator coils inside the caravan. It absorbs heat from the air, turning the liquid into gas again. This process cools the surrounding air, which is then circulated through the space.

The result is that refreshing chill you feel when the unit is running.

The Refrigerant: The Magic Liquid-Gas Cycle

Refrigerant is a substance that changes state as it travels through the system. It shifts from gas to liquid and back again. In doing so, it captures and releases heat, making cooling possible.

Without refrigerant, the entire cycle wouldn't function.

Truma air distribution unit for caravan ceiling installation, on a white background.

Types of Caravan Air Conditioners and How They Differ

Compressor vs. Evaporative Systems

Caravan air conditioning systems generally fall into one of two categories.
Each works differently and suits different needs.

How Compressor Systems Work: The Most Common Type

Compressor units use the refrigeration process outlined above. They are the most widely used systems in caravans and motorhomes. They work well in varied climates and offer consistent performance.

However, they require more power than evaporative units.

How Evaporative Systems Work: A Water-Based Alternative

Evaporative units work by drawing air through water-saturated pads. The evaporation cools the air, which is then pushed inside. These systems consume less energy and add moisture to the air.

That makes them ideal for dry regions, but less effective in humid environments.

Rooftop vs. Under-Bunk Installations

The placement of your air conditioning unit can affect both its efficiency and convenience.

How Rooftop Units Distribute Cool Air

Rooftop units are popular for their space-saving design. They sit on top of the caravan and blow air downwards. This allows cool air to spread naturally throughout the space.

They're relatively easy to install but may create more noise.

How Under-Bunk Systems Use Ducting for Airflow

Under-bunk systems are tucked out of sight inside the caravan. They use ducts to move air through vents placed strategically around the space. This makes them quieter and often more efficient in larger or premium models.

Installation is more complex, requiring proper placement and routing.

Truma air conditioner installed on the ceiling of a caravan interior with wooden cabinets.

Reverse Cycle: How Your Air Conditioner Can Also Heat Your Caravan

Some air conditioning systems do more than just cool — they can heat too.

Reversing the Refrigerant Flow for Heating

Reverse cycle systems change the direction of refrigerant flow. Instead of taking heat from inside and releasing it outside, they do the opposite. They extract warmth from the outside air (even in cooler weather) and release it indoors.

This clever trick allows one system to serve both summer and winter needs.

The Benefits of an All-in-One Heating and Cooling Solution

Having a dual-function unit saves space and weight. It also reduces the need for separate heating systems. For travellers exploring a range of climates, this flexibility is invaluable.

It keeps your caravan liveable year-round with minimal hassle.

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