G-Tools Temperature-Controlled Inline Fan 160 mm 800 m³/h

A temperature-controlled 160 mm inline fan up to 800 m³/h, with an EBM Papst motor, adjustable minimum speed, an external sensor on a four metre lead and a thermal cut-out.

Hysteresis: two degrees of slack that stop the hunting

The specifications list a hysteresis of 2 °C. It is one of those numbers you read past, while it decides whether the unit is pleasant to live with or drives you mad.

Picture a control with no slack, set to 26 degrees. At 26.0 the fan speeds up, the temperature drops to 25.9, the fan eases off, the temperature climbs to 26.0, and that repeats endlessly. Such a control chases itself: the speed waves continuously, you hear the noise swelling and falling, and the motor takes accelerations it would never see at a fixed setting.

Hysteresis solves it by pulling the up and down thresholds apart. The fan speeds up at 26 degrees but does not ease back until 24. In between nothing happens, so it holds one speed for a while before anything changes.

On this model gradualness comes on top: speed rises and falls progressively rather than jumping between minimum and maximum, and you can set the minimum yourself so it keeps running through the coolest period.

Practical note: do not be alarmed if your measured temperature sits a degree above your setting. That is the system waiting rather than hunting.

Technical Specifications:

• Flange diameter: 160 mm
• Maximum airflow: 800 m³/h
• Motor type: EBM Papst
• Power: 105 watts
• Current: 0.5 A
• Control: target temperature and minimum speed adjustable
• Hysteresis: 2 °C
• Protection: thermal cut-out
• Sensor lead: 4 metres

Frequently asked questions

Why does it not respond immediately?
Because of the 2 °C hysteresis, which stops the speed shuttling back and forth.

Can I set the minimum to zero?
Better not. A low baseline keeps moisture down and keeps your filter working.

What does the thermal cut-out do?
It switches the motor off on overheating, for instance if the airflow is blocked.