Vents VK 250 Duo R centrifugal fan Ø 250 MM

A 250 mm centrifugal duct fan with two speeds: 642 or 1126 m³/h, selected with a thyristor two-speed controller.

The VK 250 Duo R is the only two-speed version in this range whose high speed delivers MORE than the standard model. That is not a typo, and it is the reason to pick this one.

The only Duo that beats the standard

At the smaller sizes a Duo costs you something at the top. The 125 does 329 against the standard's 355 m³/h, the 200 does 741 against 780. There you trade a little peak output for a genuine low speed.

At 250 mm it is the other way round: 1126 m³/h on high against 1080 for the standard VK 250, with a 642 low speed underneath. So you give up nothing and gain a usable second speed.

What that means in practice: if you are torn between the standard version and this one, there is little to weigh up at this size. The Duo matches it at the top and additionally gives you a setting you can run on most of the time.

And that low speed is no emergency setting here. 642 m³/h is already more than a standard VK 200 delivers, so for most spaces it is simply your normal operation, with the 1126 held back for warm days.

Switching is done with the matching thyristor controller, or automatically with a timer rated for the power.

Construction

The external rotor motor has two windings, each with its own speed the motor was designed for. Otherwise the familiar build: centrifugal impeller with backward-curved blades, balanced during assembly, self-recovering thermal cut-out, bearings for at least 40,000 running hours, plastic housing, IPX4 and class II.

Technical Specifications:

• Power draw: 147 W on low, 176 W on high
• Current: 0.66 A to 0.76 A
• Connection: 250 mm
• Volume flow low: 642 m³/h
• Volume flow high: 1126 m³/h
• Motor: external rotor with two windings
• Control: thyristor two-speed controller
• Thermal cut-out: recovers by itself
• Bearing life: at least 40,000 running hours
• Construction: corrosion-resistant plastic, IPX4, class II

Frequently asked questions

Is it right that the high speed beats the standard VK 250?
Yes: 1126 against 1080 m³/h. At the smaller sizes it is the other way round; at 250 mm it is not.

Is the low speed usable as the normal setting?
Certainly. 642 m³/h is more than a standard VK 200 delivers.

Can it switch between speeds automatically?
With a timer rated for the power. Switching on temperature is what the U version does.

Which filter belongs with it?
One that can take the high speed, so at least 1126 m³/h.