SJRV Plus Fan Buying Guide: 355mm or 400mm Caravan Roof Fan?

The SJRV Plus Fan is a 12V caravan roof fan with reversible airflow, remote control and ten speed settings. It provides adjustable ventilation for caravans, campervans and motorhomes, combining a powered roof vent with a block-out blind, insect screen and LED lighting.

VanDIY offers two versions: one for a 355 × 355mm roof cut-out and another for a 400 × 400mm cut-out. Both have the same core ventilation and control features. The main choice is the opening size required for your installation.

Compare the 355mm and 400mm SJRV Plus Fans

Choose the 355mm SJRV Plus Fan or the 400mm SJRV Plus Fan to match your roof opening.

Choosing the Correct Roof Cut-Out

The cut-out is the opening through the roof. It is smaller than the outside footprint of the complete fan assembly.

A 355 × 355mm opening is commonly described as approximately 14 × 14 inches. A 400 × 400mm opening is a different size.

For a replacement, measure the existing opening and roof thickness. Also allow space for the exterior fan housing, lid movement and interior trim, particularly near solar panels, roof racks and overhead cabinetry.

The larger cut-out does not by itself indicate stronger airflow. Both SJRV Plus Fan versions offer the same core features and approximately 3,000m³/h of listed maximum airflow.

Extract Warm Air or Bring Fresh Air Inside

The reversible motor gives you two ventilation modes.

Exhaust mode draws cabin air outside, helping remove accumulated warmth and cooking odours. Opening a suitable shaded window allows replacement air to move through the interior towards the roof fan.

Intake mode draws outdoor air into the caravan. This gives you another way to manage airflow through your living or sleeping area.

The fan moves air rather than refrigerating it. It can remove trapped heat, but it does not cool incoming air below the outdoor temperature like an air conditioner.

Ten Speeds for Different Conditions

Ten selectable speeds let you choose gentle airflow or stronger ventilation.

Lower settings provide reduced noise and airflow for quieter periods. Higher settings increase ventilation when the cabin is warm or cooking odours need clearing.

The brushless DC motor provides adjustable operation, so you can select the setting that suits the conditions rather than running at maximum speed continuously.

Remote Control and Automatic Temperature Operation

Both models include a remote control and an interior touch panel.

The built-in temperature sensor supports automatic fan operation according to your selected settings. Powered lid opening and closing adds convenience, with manual lid operation also available.

These features let you manage ventilation without repeatedly reaching up to the ceiling.

Blind, Insect Screen and LED Lighting

The integrated pleated block-out blind reduces unwanted light, making the Plus Fan useful near beds and seating areas.

An insect screen helps keep mosquitoes and other insects outside. Built-in LED lighting illuminates the interior assembly.

Both versions supplied by VanDIY have a white roof lid.

Power and Installation

Both fans require 12V DC. The listed maximum fan power is 20W, with 4W LED lighting.

Plan for the fan and lighting together when sizing the electrical supply. Wiring, circuit protection, roof mounting and sealing should follow the instructions for the selected model.

The listed roof thickness range is 27–80mm. Follow the model’s instructions for lid position during travel and operation in wet weather.

Frequently Asked Questions

Can both Plus Fans extract warm air?

Yes. Exhaust mode draws interior air outside. Providing a suitable replacement-air opening helps airflow through the cabin.

Can both models draw fresh air inside?

Yes. Reversible operation allows you to switch between intake and exhaust.

Can I operate the fan using a remote?

Yes. Both versions include a remote control and an interior touch panel.

Can the fan respond automatically to temperature?

Yes. A built-in temperature sensor supports automatic operation based on your selected settings.

Do both versions include a blind, insect screen and light?

Yes. Each includes a pleated block-out blind, insect screen and LED lighting.

Will the 400mm model fit directly into a 355mm opening?

No. The models require different cut-out sizes. Select the version matching your installation.

Can I connect either fan directly to a 24V supply?

No. Both models require 12V DC. A 24V installation would need a suitably rated converter supplying the correct voltage.

Does the Plus Fan refrigerate the air?

No. It provides ventilation by moving air into or out of the caravan.

Choose Your SJRV Plus Fan

• Shop the 355 × 355mm SJRV Plus Fan.
• Shop the 400 × 400mm SJRV Plus Fan.

You can also browse our caravan roof fans and extractor vents.