EcoRenovator - View Single Post - Need help with Nest-HRV integration

bbro62 · 11-24-19, 12:01 AM

My apologies for not updating this thread or responding. I did get this working but at the same time, was starting my own business which consumed most of my time. I'm happy to report that my controller has been humming along nicely for three years now and I really like it. I uploaded arduino sketches, schematics, etc. on Github https://github.com/blbrock/Smart_HRV

I really like the system. It monitors humidity in our two bathrooms and a third reference location in the house and compares these with outside temp/humidity to adjust the target indoor humidity and decide whether to run in recirculation mode or low or high fresh air exchange to obtain target humidity with minimal energy loss. The system consists of an arduino-based microcontrooler wired directly to the HRV and is controlled through a wall-mounted tablet via bluetooth. The arduino is also connected to a Nest thermostat via a relay to take advantage of the Nest fan controller. I have the nest set to run the HRV at low speed fresh air mode for 15 minutes every hour during the day to maintain indoor air quality.

The only thing I would do different is that I would wire the manual push button controls to the arduino and run them from there instead of leaving them wired to the HRV as they were originally. I was never able to capture the full command sequence from the manual controls and pushing the controls when the HRV is in an automatically triggered cycle can sometimes cause the HRV to go into error mode and have to be powered on and off. That rarely happens so not worth changing at this point.

Here's a couple images of the system:

https://raw.githubusercontent.com/bl...controller.png

Again, sorry for not updating or answering questions.

11-24-19, 12:01 AM	#17
bbro62 Lurking Renovator Join Date: Jan 2016 Location: N/A Posts: 10 Thanks: 2 Thanked 0 Times in 0 Posts	My apologies for not updating this thread or responding. I did get this working but at the same time, was starting my own business which consumed most of my time. I'm happy to report that my controller has been humming along nicely for three years now and I really like it. I uploaded arduino sketches, schematics, etc. on Github https://github.com/blbrock/Smart_HRV I really like the system. It monitors humidity in our two bathrooms and a third reference location in the house and compares these with outside temp/humidity to adjust the target indoor humidity and decide whether to run in recirculation mode or low or high fresh air exchange to obtain target humidity with minimal energy loss. The system consists of an arduino-based microcontrooler wired directly to the HRV and is controlled through a wall-mounted tablet via bluetooth. The arduino is also connected to a Nest thermostat via a relay to take advantage of the Nest fan controller. I have the nest set to run the HRV at low speed fresh air mode for 15 minutes every hour during the day to maintain indoor air quality. The only thing I would do different is that I would wire the manual push button controls to the arduino and run them from there instead of leaving them wired to the HRV as they were originally. I was never able to capture the full command sequence from the manual controls and pushing the controls when the HRV is in an automatically triggered cycle can sometimes cause the HRV to go into error mode and have to be powered on and off. That rarely happens so not worth changing at this point. Here's a couple images of the system: https://raw.githubusercontent.com/bl...controller.png Again, sorry for not updating or answering questions. Last edited by bbro62; 09-29-20 at 04:58 PM..