Vents VK 125 Q U centrifugal fan Ø 125 MM / 260 M³

A 125 mm centrifugal duct fan combining the quiet Q motor with the built-in thermostat and speed module. Rated 260 m³/h.

The VK 125 Q U is the most equipped variant in this size: quiet motor and automatic control. It is not the best buy for everyone, and it is fairer to say when it is not.

When you are better off not automating

Automatic temperature control always sounds like an improvement. There are three situations where a fixed speed does better.

When you are managing negative pressure. If your extraction is what creates the negative pressure keeping odour inside, you want that extraction constant. A fan that backs off as things cool lets your negative pressure move with it, and at its lowest point air can leak out through gaps rather than through your filter.

When your carbon filter is doing the work. A filter only treats the air that actually passes through it. Extraction that nearly stops at night filters almost nothing at night, while the odour is still there.

When your climate is stable anyway. In a cellar or shed with little temperature swing the thermostat barely acts: you set it, it rarely triggers, and you paid for a module that does nothing.

When this version is the right one: in a space with a clear difference between lights on and lights off, where without regulation you would ventilate either too much or too little, and where you would rather not solve that with another box on the wall.

When setting it up, watch the minimum speed. The module lets you choose a baseline the fan keeps running at below the threshold; do not set that to zero if you want continuous filtering and steady negative pressure.

The two properties together

Choosing the Q motor gives up 95 m³/h against the standard version and returns a machine that runs more gently for it. Housing, bearings and cut-out come unchanged from the same range.

Technical Specifications:

• Power draw: 61 W
• Current: 0.38 A
• Duct size: 125 mm
• Capacity: 260 m³/h
• Drive: quiet external rotor motor, cut-out recovers by itself
• Built in: thermostat plus speed control on the front panel
• Sensor reads: the air inside the duct
• Bearing life: at least 40,000 hours
• Housing: corrosion-resistant plastic, IPX4, class II
• Mounting position: your choice

Frequently asked questions

Can the fan keep running at a minimum speed?
Yes. Use the speed dial to set a baseline it maintains below the temperature threshold.

Why might I not want automatic control?
If you need constant negative pressure or continuous filtering, or if your climate barely fluctuates. A fixed speed does better then.

What is the difference from the VK 125 U?
The same module with the quiet motor: 260 instead of 355 m³/h.

Does it measure my room temperature?
No, the air temperature in the duct. On an extraction fan that usually tracks your room.