Manually adjusting the settings of a roof fan vent can quickly become tiresome and inconvenient. Upgrading to smart fans like the MaxxFan Plus Power Lift 4540Ki solves these problems by allowing you to program them to maintain a specific temperature. Why does this matter?
During warmer months, you may need to leave your ventilation system running continuously to keep your space cool and comfortable. That isn't an efficient solution for your off-grid power setup, even with low-voltage fans — especially if you're relying on batteries and solar panels.
But a smart vent like this one on the roof of your van can help conserve battery power while keeping the interior comfortable. The unit also comes with a wireless remote control for convenient operation, among other features we'll highlight in this review.
What Is the MaxxFan Plus Power Lift 4540Ki?
The MaxxFan Plus Power Lift 4540Ki is an active ventilation system designed to enhance airflow in your campervan, caravan or motorhome. It's an upgrade over the MaxxFan Plus Manual Lift 4000Ki, which explains their similar appearance.
The 4540Ki fits in a standard 14 x 14-inch cutout, making installation easy if you're replacing an existing passive vent. It also features a 12-inch, 10-blade fan that runs efficiently on your van's 12-volt electrical system.
Unlike the manual 4000Ki, though, this model can be operated remotely using the included wireless controller. You can turn it on or off, open or close the vent lid, change fan direction and adjust the fan speed with ease.
The remote also simplifies enabling the fan's automatic mode — and best of all, you can program this "AUTO" function to your own preferred temperature. Once the built-in thermostat detects the van has reached that temperature, the fan motor shuts off and the lid closes automatically.
The lid serves as both a fan guard and a protective cover against rain and debris. Its most impressive upgrade over the 4000Ki is the built-in rain sensor that automatically closes the lid at the first sign of moisture. The table below compares this electric MaxxFan Plus with its manual counterpart:
| MaxxFan Plus Power Lift 4540Ki | MaxxFan Plus Manual Lift 4000Ki | |
|---|---|---|
| Housing | UV-resistant plastic | UV-resistant plastic |
| Finish | White | White |
| Weight | 4.8kg | 4.5kg |
| Mounting Cut-Out | 14 x 14 inch (355 x 355 mm) | 14 x 14 inch (355 x 355 mm) |
| Type | Electric Opening | Manual Opening |
| Fan Diameter | 12 inch (300mm) | 12 inch (300mm) |
| Fan Speeds | 10 Levels | 10 Levels |
| Fan Airflow | Intake and Exhaust | Intake and Exhaust |
| Fan Airflow Rating | 900+ CFM | 900+ CFM |
| Built-in Thermostat | YES | YES |
| Built-in Auto Mode | YES (basic and custom) | YES (basic only) |
| Power Requirement | 12V @ 5A | 12V @ 5A |
| Power Usage | 0.2 - 3.6 amps | 0.2 - 3.5 amps |
| Insect Screen | YES (removable) | YES (removable) |
| Controls | Remote control, manual knob, and keypad | Manual knob and keypad |
| Ceiling Fan Mode | YES | YES |
| Weather Protection | Built-in rain cover and rain detection | Built-in rain cover |
Full Review: 11 Standout Features of This Electric MaxxFan Plus
After thoroughly testing this MaxxAir roof vent, we can confirm there's a lot to appreciate. Here are the 11 most important features you should know before adding it to your adventure vehicle.
What's in the Box
- Electric fan unit: The core component, featuring an integrated vent lid, 12V fan, manual knob, flush-mounted keypad, built-in sensors, motorised actuator and insect screen. It also includes a moulded mounting flange and tabs for attaching a FanMate Vent Cover for enhanced weather performance.
- Interior garnish ring: A ceiling trim piece that hides gaps between the vent cutout and the ceiling, while also improving airflow direction for better efficiency.
- Remote control kit: A handheld remote for easy operation, complete with a wall-mounted holder for extra convenience.
- Installation supplies: Mounting screws, electrical connectors and a printed installation guide.
Design and Styling
Visually, the 4540Ki closely resembles the manual 4000Ki. It features a square design that fits the standard 14 x 14-inch roof opening found in most campervans and caravans. The vent comes in a classic white finish that blends seamlessly with both modern and traditional interiors, and it's lightweight, making it easy to handle during installation.
Sturdy and Durable Build
The lid and housing feature a rugged build of UV-resistant plastic, offering reliable performance even under Australia's harsh sun. Two sturdy lifting arms support the lid when open, allowing stable ventilation in windy conditions or while driving.
How Easy Is It to Install?
If you're handy with DIY projects, installing this vent is a breeze — especially if you're upgrading an existing vent. After removing the old vent and cleaning the area, you just insert the new unit and secure it with the provided screws. The flange lacks predrilled holes but includes dimples to ensure even placement of the mounting screws.
After securing the vent on the van's roof, apply sealant along the flange edges to waterproof it. Then head back inside to complete the wiring and attach the interior garnish ring.
Tip: The unit requires a 14 x 14-inch cutout for mounting. To confirm compatibility with your existing opening, place the garnish ring over the old vent's trim — if it aligns, the fan will fit perfectly.
Power Requirements
Before enjoying fresh air inside your camper, connect the fan to a 12V power source — via the battery busbars, fuse panel or a nearby circuit. The user manual specifies a minimum of 12V @ 5 amps, primarily to accommodate the motorised lid actuator. During continuous operation, however, our tests showed a power draw of around 3.6 amps on the highest speed setting.
How Do You Control It?
The vent is easy to control through its flush-mounted keypad, manual knob or remote control.
Remote control functions: The included remote allows complete control of all the fan's functions:
- On/Off button: Powers the fan.
- Vent lid button: Opens or closes the lid.
- Fan speed buttons: Adjust airflow intensity.
- Air In/Out button: Reverses airflow direction.
- Auto Mode button: Activates automatic temperature control.
- Thermostat buttons: Set your preferred Auto Mode temperature.
The remote's backlit screen clearly displays all the settings above, along with your van's room temperature, battery status and a signal strength icon.
Manual control knob: The built-in knob lets you manually open or close the lid — counter-clockwise to open, clockwise to close. It's handy for off-grid situations when the remote battery or camper's power runs low, or if you wish to leave the lid partially open. Unlike the knob on the manual 4000Ki, this one doesn't lock in place, allowing seamless operation with the remote.
Keypad controls: The flush-mounted keypad is a critical backup when the remote or camper's power is unavailable. It supports six key functions:
- On/Off switch
- Auto Mode
- Intake/Exhaust airflow
- Lid control (press "+" and "−" together)
- Fan speed adjustment (manual mode)
- Thermostat settings (Auto Mode)
The keypad also includes a dedicated button to toggle the rain sensor on or off.
Ventilation Performance
The motorised lid is one of this vent's top features. With a single press on the remote, the lid opens automatically — no more stretching or climbing to reach the keypad.
Secondly, the 12-inch, ten-blade fan moves over 900 CFM (cubic feet per minute), completing one full air exchange in a standard 1,036-cubic-foot camper in under two minutes. In an hour, that's about 52 full air exchanges, greatly improving the overall air quality inside the van. The fan's 10 variable speeds allow fine control, while the reversible motor enables both intake (cool air in) and exhaust (hot air out) modes.
Automated Operation
The 4540Ki has an advanced "AUTO" mode that includes both a 26°C factory preset and a customisable temperature setting. Once programmed, the fan automatically opens the lid, runs until your set temperature is reached, then shuts down. This ensures 100% hands-free operation — perfect when sleeping, working, driving, or if you leave a pet alone in the camper.
Energy Efficiency
Although rated at 12V @ 5A, our power consumption tests recorded lower figures. Our multimeter recorded 3.58 amps at maximum speed, which translates to 35.8Ah for ten hours of continuous operation. Meanwhile, the lowest speed, level 1, draws as little as 0.16 amps, making this fan vent highly efficient for off-grid use.
Rain Sensor and Weather Protection
As mentioned earlier, the lid serves as both the fan's guard and rain cover. The fan unit also features a sealing gasket around the rim to enhance waterproofing, plus a rain detection sensor that automatically closes the lid after detecting moisture — when we sprayed water over the sensor's circuitry, it closed the lid automatically.
Tip: The lid won't auto-close if opened manually with the control knob. You can also disable the rain sensor by pressing the "Rain" button on the keypad — its indicator will flash red when deactivated.
Maintenance
Cleaning is simple. Just remove the bug screen by turning its retainer knobs 180 degrees, then wash it using mild soap and water.
Note: Avoid detergents that contain petroleum additives or solvents such as acetone or ketones. For the fan blades, use a moist cloth with water, a window cleaner, or a low concentration of alcohol.
Is the MaxxFan Plus Power Lift 4540Ki Worth Buying?
Absolutely. It's a premium upgrade for campervans, caravans and motorhomes — especially for Australian conditions. It keeps your interior cool and fresh by efficiently cycling out hot, humid or stale air.
With features like remote control, rain detection, programmable Auto Mode and low power consumption, it offers outstanding value. These upgrades do come at a cost, though — you'll pay around $100 more than for the MaxxFan Plus Manual Lift 4000Ki.
Frequently Asked Questions
What's the difference between the 4540Ki and the manual 4000Ki?
The 4540Ki adds a motorised (electric-opening) lid, a wireless remote control, a rain detection sensor and a customisable Auto Mode temperature on top of the 26°C preset. It weighs slightly more (4.8kg vs 4.5kg) and costs around $100 extra.
Does the rain sensor close the lid automatically?
Yes — the built-in sensor closes the lid at the first sign of moisture. Note it won't auto-close if the lid was opened manually with the knob, and you can disable the sensor via the "Rain" button on the keypad.
How much power does it use?
The manual specifies a minimum 12V @ 5A, but our multimeter recorded 3.58 amps at maximum speed (35.8Ah over ten hours) and as little as 0.16 amps on speed level 1.
Will it fit my existing roof vent opening?
It fits a standard 14 x 14-inch (355 x 355 mm) cutout. To check compatibility, place the garnish ring over your old vent's trim — if it aligns, the fan will fit perfectly.
Ready for hands-free ventilation on your next trip? Order the MaxxFan Plus Power Lift 4540Ki in white from Campervan Builders today.
