Ir Heat-Controlled Kitchen Fan

Here is very simple and low-cost kitchen fen controller circuit project,  Ql senses IR from heat sources, causes U1 to switch, activates optocopuler Ul, and triggers TR1.

Ir Heat-Controlled Kitchen Fan Circuit Diagram:

The Triac is from Radio Shack, or else a 200-V, 6-A unit (C106B) can be used.