V12 Valve vs Flower Power vs Rotating Valve: Interior Finish

When people order a rooftop ventilator, the interior finish is often ticked at the checkout without much thought. That is a pity, because the piece under the ceiling is the part you look at and touch every day. It decides whether you can close the vent on a cold night, whether fingers and paws can reach the blades, where the air goes, and in two cases whether the vent doubles as a light.

All the full-size rooftop ventilators we stock, the Le Mans, the Le Mans LL and the Round, share a 230 mm roof opening, so every valve and grille in this guide fits every one of them. The choice is purely about what you want the ceiling to do. There are four candidates: the V12 valve, the Flower Power valve, the rotating valve 300 mm and the fixed large grille. A fifth, the small 140 mm grille, belongs to the exhaust ventilator and is covered at the end.

The table puts the four finishes side by side. Diameters are the overall size of the part on the ceiling, all of which comfortably cover the 230 mm hole and the 245 mm ring.

Three of the four cost the same 35 euro in basic form, so the choice is about function, not budget. The extras, an electric actuator, an LED ring or a built-in light, are what move the price.

The V12 is the technical choice: a 290 mm ABS valve only 20 mm deep with a set of adjustable louvres. Open them wide and the fan works at full airflow; angle them and you steer the air across the ceiling instead of straight up or down. In a camper that means a Le Mans set to blow does not drop a cold column of air onto the bed. In a horse trailer it means extraction is drawn from the whole compartment rather than the spot under the fan.

It is also the only valve in the range that can be closed electrically. The 12/24 V electric version, at 40 euro excluding VAT, uses a small actuator driven from a separate on/off switch, not included, so add the fan switch 89-4008 or any rocker. That matters where the ceiling is out of reach: a high-roof coach, a horsebox, an ambulance where the crew must not climb on the bench, or a dog van you want to shut from the cab before a wash. The manual version at 35 euro does the same with a lever.

It comes in white, grey and dark grey to match the most common headlining colours. If you want to control where the air goes rather than just whether it flows, this is the one.

The Flower Power is the design choice and, in its LED version, the one that removes a separate light fitting from the ceiling. It is a 280 mm closable valve in a petal pattern, engineered so that when open it presents very little resistance, so the fan under it delivers close to its full rating. Closing is a simple manual movement.

The LED version adds 21 white and 9 blue LEDs in a ring around the valve, in 12 V or 24 V. White gives a general ceiling light for cooking, reading or loading. Blue gives a night light that will not wake a sleeping child, a nervous dog or a patient and leaves night vision intact. In a camper it replaces the dome light next to the vent; in an ambulance the blue mode is a genuinely useful low-level light. At 70 euro excluding VAT it costs less than a valve plus a decent separate light, and the ceiling looks far tidier.

Colours are white, light grey and two-tone grey. The plain version without LEDs is 35 euro. The LED ring needs its own feed and switch, so order the voltage that matches the vehicle.

The rotating valve is the traditional finish: a 300 mm disc you twist to open and twist to close. Nothing to learn, nothing to break, and at 0.4 kg the lightest closable option. It comes in black, white and grey, which makes it the obvious choice for a black-lined dog van or a grey trailer interior where the other valves come only in lighter colours.

Two options set it apart. The first is a version with an integrated white light, 12/24 V, which adds 30 mm of depth and turns the vent into a plain ceiling lamp for 60 euro excluding VAT, a simpler alternative to the Flower Power LED if you do not need blue night mode.

The second is an optional micro-switch. Wired in series with the fan, it cuts the power the moment the valve is rotated closed. That solves a real problem: a Le Mans left running against a closed valve strains the motor and wastes battery, and in a fleet vehicle nobody remembers to switch it off. With the micro-switch, closing the valve is the off switch. For dog vans, horseboxes and any vehicle with several drivers, we recommend it.

Sometimes the right answer is no valve at all. A fixed grille cannot be closed, which sounds like a disadvantage until you think about a livestock trailer, a kennel van or a plant room where the point is that the vent is always open and nobody can shut it by mistake. The large grille, 270 mm across and 4 mm thick, is a honeycomb finger guard for the Le Mans and the Round. It offers the least resistance of any finish and keeps fingers, paws and straw away from the blades. At 20 euro excluding VAT it is the cheapest, in white, light grey or black.

Its smaller cousin, the small grille, is 140 mm across and made for the exhaust ventilator, the passive venturi vent, which has no motor and nothing to close. It costs 15 euro. The Winglet, Turbo II and Turbo III come with their own interior grille or shutter in the box.

Pulling it together, here is what we usually suggest when a customer tells us what the vehicle is for:

• Camper or motorhome: Flower Power with LED. One fitting gives ventilation, a white light and a blue night light, and it closes for cold nights.
• Horse trailer or horsebox: V12 electric, shut from the cab without reaching over a horse, or the rotating valve with micro-switch for a one-action shut-off.
• Dog transport van: rotating valve in black with the micro-switch, or the large grille where the vent must never be closed.
• Ambulance or welfare vehicle: V12 with louvres to steer air away from the patient, or Flower Power LED for the blue low-level light.
• Coach or minibus: V12 electric, switched from the driver's position.
• Commercial van or refrigerated body: large grille under a powered fan, small grille under an exhaust ventilator.

All four finishes are stocked in the Netherlands alongside the ventilators they fit, so fan, switch and valve go out in one parcel within 24 hours. If you are unsure which colour matches your headlining, ask and we will send a photo of the actual part.