I have a passive house project which includes air/ground exchanger for the ventilation part.
Due to 1) approximations in my maths, 2) ensuring legislation requirements, 3) me not being a professional, and 4) peace of mind, I want to monitor the air flows in the 2 intake & exhaust vents (and automatically power air extractors if need be).
It seems permanent vent anemometers do not exist on the market, only testers. So I want to make one (actually, two
) using 3D printed frame and helix that will fit inside the vent tube, ball-bearings for low speeds sensibility, and some measuring capability: ofc, phidgets.
Obviously I want to minimize the costs:
- power consumption
- hardware costs
so I was thinking about the ENC4109
* encoder phidget:
The ENC1000 consumes up to 4.2mA + encoder, or 21mW+enc, which means 184Wh a year if it were powered all the time - which isn't much already, but also the application wouldn't need permanent, µs monitoring. I figured I would "poll" for few minutes every... say, 15min, or half-hour.
* actual encoder:
The webpage about the ENC4109 doesn't have power consumption data, but I expect it to be low regarding its constitution (some kind of led emitter/receptor).
* extractor switch
I would have loved to use the PSU1000, but I live in europe. So the REL2001
, inside the outlet, will work wonders I'm sure.
Because of VINT, I was thinking of actually running cables across the house to a single control unit. Maybe using shielded cable to not tempt fate.
* control unit:
a SBC4 uses at least 1W while an idle RPi consumes about 4W (not even counting the vint hub, usb one is 0.15W minimum): hence SBC - though that already makes up about 9kWh/y. Or maybe I'll have the code running on the house's media center that will be most likely already powered 24/7.
I'll start by modelling, printing, and testing the frame+helix first, see how sensitive it is by breathing on it (not very rigorous, but I'll calibrate air speed when I buy the air extractors through their rated outputs).
If anyone reads this, is there something I forgot in your opinion? or have any thoughts about that project? thank you very much for any input!