Control an HVAC Duct Damper from Photon

Did a full tutorial write up for opening and closing an HVAC duct damper. Temperature is monitored by a sensor connected to 1 photon. 2nd photon is used to operate a duct damper. Pretty neat I think. Full Hackster tutorial here:


Very cool but I feel like I need to warn any potential implementers that closing supply vents/ducts is generally advised against by HVAC professionals. Definitely don’t completely block any supply branch!

It is possible to adjust the closed position of the duct damper with an adjustable screw if needed so the damper does not close all the way. Seems like we need a way to control the intensity of the Forced Air unit.

Agreed. I really looked at the “Smart Vents” out there but a little research revealed they are not well received by HVAC pros, you would need to measure normal pressure on the system with heat/cooling then dynamically adjust the fan speed AND the amount of cooling/heating being output to maintain the original parameters of the total system. Very cool idea for “art of the possible” purposes as 24v is all over the home but this particular use case needs additional help…I wish it didn’t because I have 3 rooms I would lock off except for when they are occupied.

The “engineers” that designed my system created such an unbalanced mess, well I had to do it myself to fix it.

Semesters of fluid dynamics, fluid mechanics,

I still feel like for most installs if you are only shutting one small room off it would be ok. A person should certainly consult an HVAC professional though.
I will be investigating further into this application. Perhaps we can control the HVAC forced air unit through high power PWM. Then we would need to investigate controlling the heat pump as well to see if there is a way to control the intensity of that as well.
I had another comment on this article on instructables from a user stating the same thing:

I think if we all put our heads together we could come up with something. Electric heat and cooling is just getting out of hand cost wise I believe with raising costs.
We are working on some current monitoring solutions which I think would couple nicely with an application like this. They are due out in the next month or two and should allow a user to monitor current consumption on every circuit in a house for a very reasonable price.

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