I'm into home automation and right now I'm trying to use my home automation system to help control my energy usage and also get an idea of how much energy I'm using. I was looking at several devices that can read the electric usage of my house and/or a large appliance like my heat pumps, but they are all fairly pricy and I really don't want to spend that much right now.
I was thinking about it, though, and I realized that since my thermostats are already tied into my automation system that I can tell how often and how long the heat pumps run for. I was thinking that if I took an ammeter and measured the current draw of the heat pump while it was running and the current draw of the air handler while the fan was on, then by multiplying it out based on how often and how long the system runs for I could determine approximately how much electricity it was using. I imagine that the current draw of the blower motor in the air handler is pretty much static, but I didn't know if the compressor used the same amount of electricity whenever it runs or if it will use more when the AC is on and it's 100 degrees outside rather than 80 degrees.
Do you guys have any idea? Just to be clear, I'm not asking how to measure the current draw of the compresser, but simply whether the current draw will be the same all the time or if it will vary depending on the outside (or inside, for that matter) temp.