So my history with this project is I live in Minnesota and my HRV PCB board fried. I always wanted something with an air economizer since our springs and falls are perfect times to take in cool outside air and condition the house rather than turning on the air conditioner or opening windows. This is where this project fits in.

I wrote up a detailed description of operation. Refer to HRV Control Narrative.docx in the source code. The wiring diagram is also attached in the library.

(1) Arduino ESP32 - Used due to the amount of GPIO required for this project. ESP8266 just wasn't enough GPIO.

(1) 120V to 5V step down power supply - Don't use the cheap power supply PCB's. I went through two other types before I found out that this was the most stable.

(2) DHT 22 temperature sensors - Inside sensor & Outside Remote Sensor. Measure inside and outside temperature and humidity.

(1) 0.96" OLED display for local indication of the mode it is operating and for temp/humidity indication. Be sure you desolder and solder pins so that board is configured for I2C communication. Instructions for SPI and I2C can be found here.

(1) 8-Channel SSR 5 Volt High Level trigger relay board

(1) LM1117 Linear Voltage regulator to power ESP32 at 3.3V

(1) Rotary Encoder KY-040 & Knob used as a push button. Future functionality to include a menu and be able to select modes of operation and control setpoints.

(1) Enclosure to house the OLED display and encloder. Get the large one. Dimensions are 100mmx68mmx50mm.