Here's a video of the unit working with the AC:
Here's the whole setup
Part one : Air Extractor Selection & Flow Considerations
The AC has the following throughputs (min-med-max) : 250/310/350 m3/h
The matching air extractor has the following throughputs: 280/360 m3/h
Therefore we will match the speeds as below:
|AC Speed||Matching Air Extractor Speed|
It's important to have slightly higher flow from the air extractor as we don't know how much back pressure either of the fan can handle. We will make sure there's a small opening for additional air intake just before the air extractor in order to avoid creating a low pressure between the two devices.
The air extractor selected : S&P TD-350/125 Z
Part two : Controller
In order to to determine at which speed the AC is running, we will measure the current using a hall effect sensor on an extension cable.
Since this is an AC current, we need to determine the RMS value or the Vpp and therefore need to use a microcontroller.
This microcontroller will control two relays : One for the on/off switch and one for the min/max speed selection.
Part three : Enclosure
The exit of the duct is quite high up (about 2m/6ft) and we need to avoid right angle bends. The enclosure below will support the air extractor on top at a gentle angle.