ESPHome home made Air Filter

This project describes how to build a whisper quiet air filter for removing smells and pollen out of your room.

The software is ESPHome and Home Assistant. The hardware is an ESP32 with a AMD Ryzen Wraith CPU cooler

Cost

The electronic parts are 17 euro including the ESP32 plus some filament

Motivation

I had a spare AMD Ryzen CPU cooler fan after upgrading my PC. I could have thrown it away or I could make a silent air filter for my sons room to remove the pollen.

Features

The main features are:

• The button turns the fan on or off
• uses ESP32's Wifi to connect to Home Assistant for control and reporting
• the ESP32 is standalone and so the cooling function will continue to operate without Wifi. Doesn't need HomeAssistant or Wifi to operate. Wifi is only needed for setup, manual control and reporting.
• no screen is needed on the device itself, all management is done via Home Assistant
• no coding is needed. Just some configuration in YAML files. In fact this repo only contains the YAML code needed.
• No resistors, capacitors or difficult soldering needed. I did use some dupont cables for the wiring.

Parts (~17 euro)

4 screws maximum 20mm long 

1 AMD Ryzen Wraith 4 pin CPU cooler fan (or another 9cm fan)

1 ESP32 or ESP8266 board 

1 12V adapter (https://nl.aliexpress.com/item/1005005815301733.html) 

1 12V to 5V converter (https://nl.aliexpress.com/item/1005006648976219.html) 

1 button (sorry no link, mine came from a toy box test button) some dupont cables 

any compatible LEVOIT-Core mini/Mini-RF air filter (https://nl.aliexpress.com/item/1005007211634559.html)

NOTE: when turned off the fan keeps turning very slowly. Other fans might not have the problem. This can be fixed by following the solution in this bugreport patrickcollins12#17 (comment)