My home has a 30 year old electric forced air furnace, a small wood stove and a fireplace.

I cut the power consumption in half by switching to an ecobee smart thermostat.

I tuned up the fireplace fans and replaced the gaskets, much better now.

I added a 8” inline fan to the HVAC to circulate the air across the 3 floors this past summer - this allowed a modest AC to cool the whole house. ( harmonized a 4-5C temp difference)

Hobby mining has been great for passive heat ( 3 nanos and a gpu rig) on the lower level.

The Avalon Q is maintaining 24C in the 3900 sqft house for the last 48hrs on eco. Granted it’s a mild 12-15 C outside today.

I’ll add a 20A circuit and use some 3d printed shrouds to pipe the heat into the HVAC with the 8” fan boosting it.