Motion Sensor - Aeotec Tri Sensor

The Aeotec TriSensor is three sensors, 45 mm across and 50 grams. Motion to say whether a room is occupied, temperature to run the cooling, and light level so lamps only come on when it is dark. That is most of what a house needs to automate itself.

• What the Aeotec TriSensor covers, and what it leaves out
• It can act without waiting for the hub
• Adjustable sensitivity, and the dog
• Three years on one cell, and where it goes
• What it needs

Z-Wave Plus with S2 security. A Z-Wave hub is required.

What the Aeotec TriSensor covers, and what it leaves out

Motion, temperature and light. In practice those three drive nearly every rule a house actually runs: is anyone in this room, is it hot, is it dark. Humidity, UV and vibration are the ones left out, and if you want those the larger MultiSensor 7 is the part. For a bedroom, a corridor or an office, three is the right three and the smaller body is easier to live with.

It can act without waiting for the hub

The temperature reading can drive a device directly once it passes a level you set, rather than reporting to the controller and waiting for the controller to decide. That is worth having on a fan or a cooler, because it keeps working during the ten minutes your hub spends rebooting after an update, and it removes the hub as a point of failure on the one rule you least want to fail.

Adjustable sensitivity, and the dog

Motion is accurate to 7 metres and the sensitivity is adjustable, which is the setting that stops a cat or a dog arming your alarm every evening. It is the first thing to change after mounting and the reason most people give up on cheaper PIR sensors, which offer no such control.

Three years on one cell, and where it goes

One CR123A lithium cell, up to three years. 45 mm across and 50 grams, so it sits in a corner bracket, on a shelf or on a beam without looking like equipment. For a flush ceiling fit there is the Aeotec Recessor, which drops it into the plasterboard so only the face shows. Temperature is accurate to within a degree and light to within 3 per cent across 0 to 30,000 lux.

What it needs

A Z-Wave hub. It runs Z-Wave Plus with S2 security, and we sell three controllers that take it: the Fibaro Home Center Lite, the Fibaro Home Center 2 and the Homey Pro.

For humidity, UV and vibration as well, look at the Aeotec MultiSensor 7. To make a noise when it triggers, the Aeotec Siren. Aeotec publish the TriSensor at aeotec.com.