Temperature difference scene: new functions to iHost with Node-Red

Published at : 23 Dec 2025

Scenes on the iHost have limited conditions, and if you want to include a formula you are out of luck. But by running Node-Red on the iHost you can implement more complex logic in Node-Red and do the simple task on the iHost itself.

In this example I show how to create a trigger for a temperature difference. Read two temperature sensors and trigger if one temperature is higher than the other. For example to ventillate/cool a green house and only turn on the fan if the outside temperature is lower than the inside temperature.

Download my flow: https://github.com/nygma2004/km/blob/main/ihost_differental_temp.json

Buy your iHost: https://itead.cc/product/sonoff-ihost-smart-home-hub/ref/33

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Chapters:
0:00 Intro
1:20 How it works
3:08 Node-Red flow overview
5:23 Prerequisites
6:06 New virtual device
7:22 Hysteresis
7:41 Reading sensors
10:28 Fan state
10:55 Switching logic
15:36 Demo the logic
18:59 Closing comments
19:26 Outro