Garden Highpro Profan TT Extractor Fan 100mm

A 100 mm inline fan with a two-speed switch: 145 m³/h at 21 watts, or 187 at 33 watts. Mixed-flow build with a copper motor winding and a plastic housing.

What the high speed costs

Two speeds sound like less air or more air, but the interesting question is what the difference costs you. On this model both numbers are given, and they do not rise together.

From speed one to speed two the airflow goes from 145 to 187 m³/h. That is twenty nine percent more air. Power draw goes, in the same step, from 21 to 33 watts, which is fifty seven percent more electricity.

So you pay twice for the high setting: nearly double the extra power for the extra air you get back. That is not a design fault but physics. The power a fan needs climbs far faster than its flow, roughly with the cube of speed, and here the speed goes from 2180 to 2385 rpm.

In practice: use the high setting when you need it, not by default. In the dark period 145 m³/h is almost always enough, and it then runs at two thirds of the consumption and noticeably quieter.

Note too that both figures are measured blowing free. With a filter and a few metres of ducting attached you will keep less.

Technical Specifications:

• Connection: 100 mm
• Speed 1: 145 m³/h, 2180 rpm
• Speed 2: 187 m³/h, 2385 rpm
• Power, speed 1: 21 watts
• Power, speed 2: 33 watts
• Motor winding: copper
• Housing: plastic, opens for cleaning

Frequently asked questions

Which setting when?
High with the lamp on, low in the dark period. That way you do not pay for air you do not need.

Will I get 187 with a filter fitted?
No, that is the free-blowing figure. A filter and ducting always cost some of it.

Can I fit a dimmer?
This model is built for two fixed speeds.