Estimating HVAC power

Share your Projects!
1

I’m in an area where it gets really cold and much of my energy usage is heating. I wanted to split it out from the rest of my energy. However, I didn’t want to go through the effort of getting a CT clamp or adding wires to my circuit breaker, so I set up an estimation system. Here’s how it works:

  1. There’s an input boolean called “heater on”
  2. When the thermostat claims it’s below the minimum temperature, the input boolean turns on. When the thermostat claims it’s above the minimum temperature or the boolean has been on for a few hours, the boolean turns off.
  3. There’s a template sensor called “HVAC Power” that outputs the whole house power use minus 2.5 kW (normal high) if the heater is on, and 0 otherwise
  4. There’s an integral sensor (with left side sum and 1 minute maximum) called “HVAC Energy” that lets me add the data to the energy dashboard

I only set this up yesterday but it’s working alright. If you think there’s a way to get more accurate estimations let me know. I haven’t found any prior work or alternative methods yet though.

2

Your estimation system is a clever way to track heating energy use without extra wiring. Using HVAC estimating services can help fine-tune your calculations by factoring in equipment efficiency and runtime patterns for more accurate results. Testing this setup over a longer period or comparing with your energy bills could help verify its accuracy.