I'm currently working on one project that requires the control of heavy appliances like the air conditioners and refrigerators. I'm using the ESP8266 to control the appliances. I'm able to control the lights and fans using my existing circuit with the relays but in many forums I found that I can not control heavy appliances using the same circuit. Do I need to do something special in my circuit to control the appliances? So can anybody let me know how can I control these types of appliances? I'm talking about switching it on/off, not the remote control. If anybody can provide me with the logic or the circuit diagram, it would be a great help.