So, you only have the budget for one fan-assisted roof vent but aren't sure which type is right for your camper? Have you considered a dual airflow fan roof vent? Unlike one-way options, a dual airflow caravan roof vent can effectively improve your van's air quality at any time of day or season, though the overall experience varies depending on the features and capabilities of the model you choose.
Dual airflow fan roof vents are among the most versatile active ventilation systems for campervans, caravans, RVs, and motorhomes. They're effective not just for general ventilation, but also for situational and seasonal needs.
In this post, we'll cover everything you need to know about this type of fan-assisted roof vent β including what it is, its three major benefits, and some of the best brands available today.
What Is a Dual Airflow Fan Roof Vent?
When shopping for a roof vent for your adventure van, you'll notice they're typically categorised as intake, exhaust, or dual airflow. Simply, the airflow type determines the direction in which the integrated fan operates.
For intake roof vents, the fan draws fresh, cool outdoor air into your vehicle, whereas exhaust roof vents have the fan expelling hot or stale indoor air out.
Meanwhile, a dual airflow roof vent can operate in either intake or exhaust mode. With a simple switch, you can reverse the fan's rotation β from clockwise to anticlockwise (or vice versa) β which is why they're also known as reversible fans. This reversible directionality makes a dual airflow fan roof vent the most versatile ventilation option, allowing you to tailor performance to suit any situation.
Why Choose a Dual Airflow Roof Vent Fan? 3 Key Benefits
The debate over whether an intake or exhaust fan is "better" is common in online communities. Some swear by exhaust mode only, while others insist intake mode provides faster cooling.
The truth is that both intake and exhaust airflow are essential for maintaining comfort in your campervan, caravan, or motorhome. Hence, a dual airflow fan roof vent offers double convenience, supporting all key applications:
- General Ventilation: A dual airflow fan roof vent improves overall indoor air quality by pulling in fresh air and removing moisture, excess heat, odours, smells, or fumes/smoke.
- Situational Ventilation: The reversible directionality of this fan is especially useful when you need targeted airflow β such as expelling cooking fumes or shower steam.
- Seasonal Ventilation: Unlike one-way vents, dual airflow roof vents also offer year-round flexibility. You can use exhaust mode during hot summer months and intake mode during cool autumn weather.
Ceiling Fan Mode
Many fan-assisted roof vents include a ceiling fan mode, which allows the fan to operate with the lid closed. Dual airflow models are still more convenient in this mode, as you can switch direction depending on your needs. For example:
- You can run the fan in intake mode to circulate air, helping regulate temperature and create a skin-cooling effect through sweat evaporation.
- In winter, you can use exhaust mode to pull warm air trapped at the ceiling down into the lower living space.
What's the Best Dual Airflow Caravan Roof Vent?
At Campervan Builders, we offer more than a dozen 12V fan roof vents with dual airflow functionality. The best option for your adventure vehicle depends on your budget, intended application, and desired features. Here are a few examples:
Maxxfan Deluxe Power Lift Dual Airflow Fan Roof Vent
The Maxxfan Deluxe Power Lift is the overall best dual airflow fan roof vent in our current catalogue. It features a sleek, rainproof design that allows operation with the lid opened during rain without letting water into the van.
The roof vent includes a reversible 12V fan with ten variable speeds for optimal airflow control depending on your ventilation needs. For instance, you can set the fan to its highest speed when your van feels like a hot box, then adjust to a lower speed once it cools down.
As a smart dual airflow roof vent, this model features a built-in thermostat and an adjustable automated control mode. When enabled, the automated mode allows the roof vent to open the lid and turn on the fan automatically when the room temperature rises above your thermostat setting.
Other available features:
- Electric-operated lid
- Durable, UV-resistant build
- Heavy-duty ball-bearing motor
- Over 900 CFM airflow capacity
- Supports ceiling fan mode
- Includes wireless remote control
- Compatible with standard 14 x 14-inch cutout
- Tool-free removable insect screen mesh
- Comes with a limited lifetime warranty
- Easy-to-use manual controls (flush-mounted keypad and lid knob)
Maxxfan Deluxe Manual Lift: The Alternative Manual Model
We also offer the Maxxfan Deluxe Manual Lift Dual Airflow Fan Roof Vent if you'd like to save a bit of money. It provides all the features of the electric version except the remote controller, motorised lid, and customisable thermostat auto mode.
As its name suggests, this model can only be operated manually, using the flush-mounted keypad for electronics and the three-winged knob for opening and closing the lid.
CVB-RVE-6000-AIR Electric Dual Airflow Fan Roof Hatch Vent
The CVB-RVE-6000-AIR Roof Hatch is an ideal choice if you need a budget-friendly dual airflow vent with an electric-operated lid. At about half the price of the Maxxfan Deluxe, it includes a motorised lid that you can easily open or close using the supplied remote controller.
The remote controller also allows you to reverse the fan direction and enable or disable the built-in rain sensor. The rain sensor automatically closes the lid when it detects moisture, so it's best to leave it enabled to avoid unexpected wet surprises.
You can also use the remote controller to adjust the operating speed of the built-in fan. However, unlike the Maxxfan unit above, this model's reversible fan has only three speeds for either intake or exhaust. It also lacks modern features such as a built-in thermostat and programmable auto mode.
Other available features:
- Supports ceiling fan mode
- 25.76 CMM airflow capacity
- Removable insect screen mesh
- Requires a standard 14 x 14-inch roof opening
- Includes one-year replacement warranty
- Manual controls (flush-mounted keypad and lid knob)
CVB-RVM5000 Manual Hatch Dual Airflow Fan Roof Vent
The CVB-RVM5000 Roof Hatch is an excellent choice if you need a reversible fan roof vent but have a tighter budget. While it doesn't include a remote controller for wireless operation, it still offers great features to enhance your ventilation.
For instance, the roof vent's fan provides three operating speeds to help you control airflow into or out of your camper efficiently. The fan delivers 25.76 CMM on the highest setting, while the lowest speed offers 13.38 CMM.
As a manual lift model, the CVB-RVM5000 has an integrated four-winged knob for opening and closing the lid. It also includes a rotary dial for controlling fan speed in both intake and exhaust modes. But unlike most fan-assisted vents with balanced settings, this model has three speed options for exhaust and two for intake.
Other available features:
- Sleek low-profile design
- Smoked UV-filtering lid
- Built-in insect screen mesh
- Suitable for standard 14 x 14-inch roof openings
- Includes a one-year replacement warranty
CVB-SRV280-LED Manual Shower Dual Airflow Fan Roof Vent
The CVB-SRV280-LED Shower Roof Vent is one of our dedicated dual airflow fan vents designed for a camper's shower or bathroom space. It is also one of the most compact models in this category, requiring only an 11 x 11-inch roof opening.
To give you optimal airflow control, this shower roof vent offers multiple fan speeds β three for extraction and two for intake. It also has built-in LED lighting around the interior trim, so you won't need a separate light fixture for your shower or bathroom.
Like any other fan vent, this unit has built-in controls for all its functions: a manual knob for opening and closing the vent lid, a rotary dial for fan speed and direction, and a separate push-button switch for the LED light.
Other available features:
- 6 CMM airflow capacity
- Removable insect screen mesh
- Includes a one-year replacement warranty
How Much Airflow Do You Need? CFM and CMM Explained
CFM (cubic feet per minute) and CMM (cubic metres per minute) are the common units used to indicate the airflow capacity of fan-assisted roof vents β whether one-way or dual airflow. Airflow capacity refers to the volume of air a fan can extract or push into a space over a given time.
It's important to consider airflow capacity when choosing a dual airflow fan roof vent for your campervan, caravan, or motorhome. The larger the space, the higher the airflow you'll need β and the higher the airflow capacity, the faster the system can ventilate your room.
That said, achieving higher airflow capacity requires operating the fan at higher speeds. And the faster a fan runs, the more power its motor will draw. The table below shows the speed settings, airflow capacity, and power draw of the fans in the five roof vents discussed above:
| Model | Dual Airflow Fan Speed | Airflow Capacity | Fan Motor Power Draw |
|---|---|---|---|
| Maxxfan Deluxe Power Lift Dual Airflow Fan Roof Vent | 10 Speeds | Over 900 CFM | 12V @ 3.8A |
| Maxxfan Deluxe Manual Lift Dual Airflow Fan Roof Vent | 10 Speeds | Over 900 CFM | 12V @ 3.6A |
| CVB-RVE-6000-AIR Electric Dual Airflow Fan Roof Hatch Vent | 3 Speeds | 25.76 CMM | 12V @ 2A |
| CVB-RVM5000 Manual Hatch Dual Airflow Fan Roof Vent | 3 Speeds | 25.76 CMM | 12V @ 1.6A |
| CVB-SRV280-LED Manual Shower Dual Airflow Fan Roof Vent | 3 Speeds | 6 CMM | 12V @ 1.2A |
More Features vs Cost vs Sacrifices
If you're adding a ventilation system to your campervan, caravan, or motorhome, a dual airflow roof vent is highly recommended. Unlike one-way (exhaust-only or intake-only) vents, dual airflow models allow you to switch between intake and extraction depending on your needs.
However, dual airflow roof vents are typically more expensive than one-way versions. The more features a model has, the higher its price tag will be. For example, the Maxxfan Deluxe Power Lift is the most sophisticated model in this category. But to enjoy its advanced features β such as a fully rainproof design, remote controller with display, customisable auto mode, and more β you'll need to budget a little over $600.
Still, proper ventilation is essential for keeping your van comfortable and preventing mould, mildew, and fungus. So, making a few sacrifices to get a good reversible fan roof vent is 100% worth it.
FAQ: Dual Airflow Caravan Roof Vents
What is the difference between intake, exhaust and dual airflow roof vents?
Intake roof vents draw fresh, cool outdoor air into your vehicle, exhaust roof vents expel hot or stale indoor air, and dual airflow (reversible) roof vents can do both β you simply switch the fan's rotation direction to change modes.
What size roof opening does a caravan roof vent need?
Most dual airflow fan roof vents, including the Maxxfan Deluxe and the CVB roof hatches, fit a standard 14 x 14-inch roof opening. Compact shower vents like the CVB-SRV280-LED require only an 11 x 11-inch opening.
How much power does a 12V roof vent fan draw?
Among the models covered here, power draw ranges from 12V @ 1.2A for the compact shower vent up to 12V @ 3.8A for the Maxxfan Deluxe Power Lift at full speed.
Are dual airflow roof vents worth the extra cost?
Yes. While they cost more than one-way vents, reversible fans support general, situational, and seasonal ventilation, and proper airflow helps prevent mould, mildew, and fungus in your van.
Ready to improve the airflow in your camper? Explore the full range of 12V roof vents at Campervan Builders and find the right dual airflow model for your build.
