Are Lennox Variable Speed systems learnable? SLP98V, XC20 AC, iComfort S30?

Hey guys - just recently upgraded my furnace and AC, these systems however, are fully modulating.

Can sense learn these? Does anyone have one that has been learned?

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Found our furnace… Not sure how to do this… But look for “Variable Speed Motor Detected” from a couple of weeks ago… If you need more information, let me know… Later…Gerry

I have 3 Lennox systems, 2 heat pumps and 1 air handler/furnace (dual fuel system with older Trane heat pump). They are all variable speed and Sense has detected all 3. I haven’t verified which of the motors it has detected yet and if it’s just the condenser outside or if it also combined the air handler. It hasn’t gotten cold enough here for my furnace to kick on yet to know if the air handler portion will show on.

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The Sense summer push to improve the detection of variable-speed ACs, now extended to winter heat mode in heat pumps (!), I think was best detailed by @MaheshAtSense (who I believe is the main driver at Sense in that regard) in this thread:

Detection of ramping or otherwise more complex signatures has certainly improved. The seasonal variation in usage of these devices I think translates to a kind of season-scale improvement.

Just following up as it’s quite cold outside and furnace kicked on overnight. Unfortunately the Lennox air handler hasn’t been detected as it ran overnight to run heat from the furnace. What has been must be the heat pump outside which is only used for heat above 40 degrees and AC.

You will need many operating cycles (tens to hundreds) before a Sense device model can be built for the device. I’d expect to be well into the heating season before you see a detection. Of course, due to the specifics of your home and equipment, the detection is not guaranteed.

Very true but FWIW the air handler also runs when the heat pump runs too. Same device blowing either cold or hot air. And it has been running since I installed Sense at the end of August. Unfortunately it hasn’t been detected yet and I am guessing my other HVACs that were detected are inky the outdoor heat pumps.

I see. One thing that I’ve noticed with Sense device models is that it seems to be possible for the monitor to classify and capture an appliance’s entire usage profile, even if part of that profile is a difficult-to-identify slow ramping pattern such as a variable speed air handler blower ramping up, if there’s a different component with a distinctive inrush profile that operates in tandem with the other components. For example, Sense will not see my variable speed blower motor start on its own, but if it sees the compressor inrush at the start of a cooling/heating cycle, it will properly classify the blower current as well. Including the ramp-up a few minutes into the cycle.

I think you might have a chance of seeing a different device pop up that includes the furnace-mode blower usage once Sense has some data on the other furnace components that start before a heating cycle: the inducer motor, igniter, and gas valve. If you get a detection at all, it will probably use the inducer motor inrush as the trigger for the beginning of a cycle.

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