Freezer to Refrigerator Conversion
Introduction
Convert a freezer to a refrigerator, and reduce energy consumption 12x so that your refrigerator uses 8 Watts of average power.
Nearly every household on Earth has a verticaldoor fridge that wastes not only food, but also about 1 kWh of energy each day (~365 kWh a year). Some vertical-door fridges waste as much as 3kWh each day. In a country of a few million households, replacing vertical door refrigerators with chestfridges can save enough energy to allow closing down at least one large power station. Alternatively, construction of a new power station to meet the increasing energy demand could be avoided or delayed. http://mtbest.net/chest_fridge.html
Original Work
This work is based on the Mt_Best_Freezer_to_Refrigerator_Conversion. Important point: reduce power usage to 8 watts for refrigerator.
Wiring Diagram
BOM
- Arduino Gemma $9.95
- or adafruit Trinket $6.95
- or sparkfun Pro Micro $19.95 - Install Instructions
- 24-280VAC Relay $9.95
- or SainSmart Relay Module $3.99 - Requires 5V Board
- Thermister $0.75
- 10k Resistor $0.95
- USB 5V Charger $3.95
- USB Micro Cable $1.95
- Junction Box $7.23
- Twin-screw cable clamp HomeDepot
- Extension Cord - Ace Hardware
- 2 Conductor Speaker Wire - Ace Hardware
Arduino Code
//A1 read voltage
//D3 sensor power
//D7 relay (+)
volatile int sensorvalue = 328; //define the variable
int triggeron = 328; //number that will trigger fridge on
int triggeroff = 304; //number that will trigger fridge off
// the setup function only runs once every time the chip is reset
void setup() {
digitalWrite(3, HIGH); //for powering thermister
digitalWrite(7, LOW); //for switching relay
pinMode(3, OUTPUT); //begin operating pin
pinMode(7, OUTPUT); //begin operating pin
delay(20000); // wait for thermister to get a good initial reading
}
// the loop function runs over and over again forever
void loop() {
sensorvalue = analogRead(A1); //read sensor
if (sensorvalue > triggeron){ //if sensor reads over triggeron, turn on
digitalWrite(7, HIGH); //turn on relay
delay(8000); //wait 8 seconds
}
if (triggeroff > sensorvalue){ //if sensor reads below triggeroff, turn off
digitalWrite(7, LOW); //turn off relay
delay(8000); //wait 8 seconds
}
}
Other Options
- http://mikeysklar.blogspot.com/p/yatc.html
- https://www.amazon.com/gp/product/B0002EAL58
- https://johnlvs2run.wordpress.com/2009/10/08/chest-fridge-conversion/