IAQ - One of my many passions is indoor air quality and I tend to build projects on its monitoring and control to better understand and optimize the indoor environment that we spend so much time in.
Monitor
early on my monitoring projects consisted of spreading remote temperature sensors around the townhouse i lived in at the time to help balance the heating and cooling between levels and rooms. this later developed into a system that plugged into the thermostat that would turn on the furnace fan when temperatures varied above a setpoint to help equalize the floors.
My newer projects include a mobile battery powered device that monitors and displays humidity, pressure, temperature, pm2.5 (dust) levels, light levels and co2 levels. This is an easy way to get an idea on why the air feels a bit off in a room
Modeling
a bit boring for a web page but ASHREA - which is a society in America - has many procedures for modeling airflow and quality along with many other things. I learned these during my Masters and build spreadsheets that show what modifications are needed to the hvac system and ducts in order to have better air quality.
Control
This is the fun part in which you can build automated systems that help you be more comfortable while saving some power at points.
My current project which I will start posting about is a small portable HRV (heat recovery ventilator) which i am working on for the little cabin that i am staying in during the current pandemic.
it uses common electrical parts like the esp32, coroplast and a bunch of 3d printed parts to recover the energy of outgoing stale air and use that energy to heat up incoming fresh air.
Currently the design achieves around 40% recovery which is not to bad for a parallel flow system which maxes out around 47% recovery. This is just the base design held together with friction with no seals or optimization.
I am currently working on more control through a web interface and investigating switching to a counter flow design which can get into the 90%+ range for heat recovery
Again i'll add some photos and videos when I get a chance to better document this project