How to measure KWh of my Furnace

Hi guys I am looking for way to to measure KWh of my Furnace I have DSB09104-ZWUS but my furnace is 110V single phase, any idea how can I do this whith DSB09104-ZWUS or with other device?

Do you have the brand and model of the furnace?

Is the furnace plugged into an outlet or is it hard-wired? I have mine plugged into an outlet and I use this:

And this is the display on the SmartThings app:


My Furnace is hard-wired but I can change to outlet but I am afraid if the outlet switch fail…

@JDRoberts I don’t have here the model/brand tomorrow night I will check this.

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I know these are made for whole home, but there is not reason they cannot work on a hardwired appliance such as a furnace as well.

I really do not think you should change a furnace to a plug outlet. It is hardwired on a dedicated circuit for a reason…not getting unplugged. It might not pass code if you do that.

The power a furnace pulls is to run the fan and the electronics, assuming it is a gas furnace. An electric would draw way too much current for a simple plug, anyway. A/C runs on 220. That is what pulls the power during the summer.


Sorry, hope I’m not stealing this thread…but this is on point. Let’s say, hypothetically, that I want to monitor the amount of energy that my AC unit is using all by itself. It would be on 220 line of course.

Can you use the Aeotec meter shown above and just use it on that one circuit. I’m talking the whole nine too. Powered from the electrical panel and everything. It seems logical that you could just put one clamp around each leg of the wires going in to the one single breaker. Right?

I’m just trying to ascertain if this is a guess…or a known fact…?

Also they make two different flavors of that device. Any differences of note?

A guess :slight_smile: I am looking into this same device for a similar application. A 2,000 SF home with two 20 year old HVAC units. I am looking to upgrade all house mechanical in two years and I wanted to capture a baseline. I am undecided if I go with 3 Aetoc units (whole home and 2 HVAC) or a smart sense type whole home solution.

The Q&A on Amazon addresses this very question; you have to scroll down a bit:

I am unaware of there being two versions. Are you sure you are not talking about previous generations? That is not obvious from their website.

OK, good info. I figured that logically it would make sense that you could just put the clamps on the circuit that you want to monitor. I mean, in theory, it’s the same thing as putting it on the leads that come in to the house.

Anyway…here’s what I meant by there being two versions. i suppose I could dig into this more myself…but there’s a substantial price difference and I just wondered if anyone already knew.

Obviously one is Z-wave the other is Z-wave plus…so maybe one is the old model.

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Gen 1 vs Gen 5. Not sure of the feature differences though. Gen 5 is Z-wave plus and alleges to work better confined to metal boxes.

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if you are not already monitoring whole-house power, that is more useful. It will tell you so much more about everything in the house.

if you ARE monitoring whole-house power, then you can tell when the furnace is running by the difference. Variable speed is a little more complicated but still do-able with logic.

hI @JDRoberts I have Gas Furnace, Single Phase, Brand Bryant, Model 310AAV/JAV.

I have many HEM’s.

Some in my panel, one on my furnace, dryer, microwave, and stove. They work great and are dirt cheap.

Search and you’ll find a number of threads showing installations and energy graphing methods.

Or put a HEM on the whole house, and many others on different circuits, then it’s easy to spot random loses from devices that are behaving badly, or you didn’t know existed. :wink:

And in a heavy electrical usage home, makes it far more accurate to use wattage measurements as conditions for actions…

@michaelahess, that was exactly what I was planning. For energy monitoring, ST integration is not all that important to me as I do not plan to take any automated actions based on current energy usage. But like the OP, I do want to measure energy usage on selected circuits, my HVAC/furnace being one of them (two of them actually)…as well as whole home.

I do know there are whole house options that can intelligently pick out specific loads, but I was looking at the aetoc options instead as I think I would prefer discrete monitoring on certain branches. I have not found any energy monitoring approaches that can mix intelligence and discrete.

Using ST as the gateway for the HEM readings into InfluxDB to be manipulated as needed was what I basically meant. Even if you don’t use ST for actions on the energy readings.

I tried one of the intelligent systems, it was more like a dead fish. I can do it better myself with the discrete readings.

All my HEM’s are Gen1. The new version measures watts and amps with accurate voltage readings, so it’s a bit more accurate, but not enough to make a real difference for most people. I can easily discern a 1 watt change, and my monthly calculations are always within only a few tens of watts ± the actual utility billing.

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Zooz Z-Wave Plus Power Switch ZEN15 for 110V AC Units, Sump Pumps, Humidifiers, and More

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Will that be useful or you want to see the data just because?
My furnace is what uses the most electricity in my house like yours maybe. My electrical bill is higher with the furnace on in the winter than AC on in the summer. So once you know how much it costs you which is not that hard to figure out just looking at your bills, will you be spending $5,000 to $8,000 to change your HVAC to get a more efficient system?

For me personally, its exactly that. I want to see how much money is on the table to be saved before I decide how much money I should spend to save money. Additionally, as I do other improvements in the house, I am hoping to see a reduction in energy usage. I already spent the holidays replacing all light bulbs in the house to new LED’s - over 80 of them. Only the ceiling fans remain. It’s taking me several years to bite the bullet but I finally found a high value CRI bulb that me and my wife liked. We made the switch. I don’t have a baseline for what that reduction will be so I can only speculate based on where my electric bill comes in vs where I thought it should be. Insulation and HVAC contracts are a lot more expensive than replacing light bulbs, so I want to gather some real data first.

Before you do improvement check if your gas or electricity provider offer home assessments. Most do, it’s free and you can get freebees like extra attic insulation.

If you want to gather the data it makes sense to get once of these devices, check out SENSE as well some other here: