Hardware Suggestion power metering single 120v outlet

I’m looking for some hardware suggestions for metering power usage. I have wood furnace that has a mechanical thermostat that reads fire temp and then circulates air into my main duct work. I can control the fire blower the wood furnace no issue. However I have some additional air circulates that turn on with my standard furnace. My goal is to get those to turn on when the wood furnace air blower turns on. Being its mechanical, measuring wattage I could turn on the air circulation fans based off wood furnace power draw.

However there is a couple catches:

  • Needs to be able to wired in directily to 12-2 or 14-2 , 120v
  • Can’t be a switched meter

Reason it can’t be switched, the wood furnace also uses the air blower to cool the firebox. If power goes out or is loss…temps could reach an extreme that would make duct work start to melt/smell or possibly other damage near wood furnance.

So far everything I’ve found has a switch built into it, which is just to risky.

Currently I use:
Openhabian 2.4
and starting to build some esp8266 sensors, but haven’t gotten everything in yet.

Any thoughts on best route for this?

I use an Aeon Labs home energy monitor to detect if my dryer is running. Works with 120v or 240v and senses using non contact inductive sensors.

I’ve also seen this done diy if you’re adventurous, but I got an old model of the above device for $15 so it was a no brainier.

Yes I have one around my main, maybe I can find a Gen 1 cheap and just use one clamp.

Can you not just use a relay or is it in another location from your furnace?

You could use the Tasmota firmware on your ESP with the PZEM-004T sensor.

My guess is the Z-Wave CT would be the simplest route, rather than programming the ESP. One thing you would need to watch out for is some CTs have a minimum current they need to show load and if it is just a small blower the CT might not be able to read it.

Standard furnace is located different location from the wood furnace although in the same basement. The wood furnace blower is actually a bit larger than my standard one. It pulls around 700-1200 watts anywhere from 1000cfm to highest setting of 1800cfm. I was able to purchase a gen 1 aeotec energy meter for $25 last night. I’m hoping to create a rule when sensor x sees x amount of wattage send command turn on other air handlers.

Just a follow up to how this is going. I ended up putting in that aeotec energy meter, no matter what i try it doesn’t pick up but 6 watts. However that is enough for me to create my trigger. All is going well, however its a huge waste of the sensor. Later on I’ll wire something inline, but this works for now.