Residential Night Cooling automation with a Raspberry PI

and few other components

The Result

The idea

Night Cooling is a very efficient way to save energy by cooling a house with the colder air at night. Most people don't use it because it requires to manually turn on a Whole House Fan and open windows. Automation mechanisms are available but very expensive.

My project aims to solve the issue by building an inexpensive automation device using a Raspberry PI and a relay board. It has a couple of inside thermometers and an outdoor wireless thermometer. When the outdoor temperature is a few degrees cooler than the inside temp, the relays activate an actuator to open a window and turn on a whole house fan (both modeled with a Lego). It also has an LCD display to show temperatures and set a few options.

Do it yourself!

I'm providing very high level instructions for this project. I'm planning to add more detail later. Sorry!!

For this project you'll need:

Raspberry PI, Slice of PI, a CISECO Temperature sensor with 2 XRF modules, a relay board, a LCD display, a few resistors, cables, sodering tools.

Here are some of the components I bought:

Some of the components

Step 1:

I followed these instructions to connect a temperature sensor directly to the raspberry PI:


These instructions are needed to connect the LCD display to the PI:

Step 3 - the hardest one - :

Start using a remote temperature sensor!

Step 4:

The connection of the relay board was trial and error. What worked for me was: Connect the Gnd pin to a Gnd pin on the PI. Connect the VCC pin to a +5v pin on the PI. Connect IN1..4 to some free GPIO's. Leave the jumper JD-VCC - VCC connected.

Step 5:

It order to use it in the real world you should install the raspberry PI + LCD on a case.

The Code

Download the files here

Execute it the program with these commands:

sudo modprobe w1-gpio
sudo modprobe w1-therm
sudo python

I also added a startup action to the Raspberry PI so the program starts automatically after it boots, and the exit option on the menu shuts down the PI completely.

How would this work in real life?

First, if you are unfamiliar with the concept of night cooling, here is a good place to start: Night_Ventilation_Hoeschele_051311.pdf

You could use your current windows or install a vent close to the ground (air is colder near the ground) that will be opened by an actuator by the PI.

The best option for the fan is to use a whole house fan as seen on the image below, but using a window fan will also do the job.

Please share your thoughts with me. I'd love to hear from you.

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