Blathering | Raspberry Pi to Monitor Air Quality with an Arduino based Thermostat

Arduino Test Board.jpg

I’d like to call myself a tinkerer, but I don’t tinker enough hold that badge. I do like to look at other projects and see what is out there for things to make my life more efficient. My target is to make my home, work for me, to automate every aspect that is feasible that has real value to me that will make life a little more efficient and have a bit better resolution on the control of the world around me. One area that needs some work is the HVAC (Heating, Ventilation and Air Conditioning) controls. I have been pondering this for a while and I think I have a good project plan to make my house work for me just a little bit better.

This is just a blathering of a project to come. If you have any thoughts or suggestions, think that this is ridiculous and a waste of time, fire those off too. I’m open. It may not change my mind but it is always worth listening to a dissenting opinion.

Project Goal

I want a home thermostat and environmental control system that is under my control and doesn’t babble off to a cloud someplace. I want it to be intelligent enough to manage the room temperatures, know if a window is open in the house, adjust the dampers in my ducting to cycle air between the floors differently depending on the time of year. I want it to be aware of the current outdoor weather as well.

Why Weather Aware?

Weather Station.jpgI want the system to know how humid it is inside and outside of the house. Much of the summer in Michigan, I don’t need to have the air conditioning on, but I do want to keep the humidity down inside of the house. I also prefer my windows open to closed, so it would be nice if I could have my thermostat would know if windows are open. There is no reason to dehumidify the house when my windows are open.

Targeted Features

The Arduino portion can handle a lot of the functions I am targeting but there is another angle, I am interested in knowing what the pollution is inside the house. I have only dug into this a little bit but the Enviro Raspberry Pi Accessory is able to measure indoor air quality, humidity, pressure, light and noise levels. This could even tell me how effective my filter is too and find the most cost effective filter that does the job. It would allow me to run a Design of Experiments to test and maximize the cleanliness of the air in my home. I don’t know the extent of the on board air quality sensor but it could really do the job.

The Plan

Thermostat.jpgConfigure and build the Arduino thermostat, that is robust, reliable and extensible to control the HVAC system. Once I can do that reliably, I’ll add more sensors to it, window sensor, temperature sensors of different rooms, duct pressure at the blower, then I can start to add automated dampers in the system to control temperature leveling in the house more precisely. Also, to shunt airflow to unused rooms in the house as well during extreme weather conditions. I want to have all the data, inputs, outputs, status and so forth to be accessible on my network so that at any point in time from any computer terminal, I can look at my “environmental system” status. Of course, it will somehow be running openSUSE Linux, someplace. Either a Raspberry Pi running openSUSE or better yet, something x86 based. It’ll be incredibly, joyously nerdy.

Next Steps

For now, I am still gathering information, parts lists and so forth. The first step in this chain will be to replace the thermostat with an Arduino Smart Thermostat that will have better functionality. Once that is working and I have a good understanding of how to manipulate it. I will start to add sensors to it. From there, I’ll figure out my greatest need to further improve efficiency and add the functionality needed.

References

Enviro Raspberry Pi Accessory to Monitor Air Quality at FOSSBYTES.com

Arduino Smart Thermostat

JohnsonControls.com equipment dampers and louvers

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