and had two in our previous home because it was better configured for one in the basement.

We swear by them! Big savings on the electric bill, so it gradually pays for itself.

...I would be very angry that the companies that I am invested in are not jumping head first into the ground floor of the non-fossil energy industry before the fossil fuel industry starts dying.

And methane is only one aspect of that "sell-by-date" industry.

One downstairs, in the living room, one in the main bedroom one in the office and one in the attic guestroom. I'm really happy with them.

No air vents, so heat pumps would be a very expensive upgrade.

On the other side, we also have no air conditioning. So we don't burn in hell later by cooling our house now.

In New England, it is very common to have either forced hot water or steam heat. With either system, you don't have air ducts throughout your house.

If you have added a/c, it was via window units or half splits. A half split could use a heat pump, but I don't know of anyone heating their homes up here with one.

Took a few months to get it set up properly (bad motherboard that was covered by warranty) but it's run great since. It's a Carrier unit that functions down to 20F before the smart thermostat switches over to the propane furnace, which is happening less often now as our Minnesota winters are getting more mild. We burn half the propane we once did, to the point our 500-gal tank only gets filled once a year. And it cools and dehumidifies great in summer as well.

The next step is replacing the 20 yr old water heater with a heat pump version, which apparently is very efficient as well.

By the time we need to replace the furnace and heat pump again in 15 yr, heat pump tech may be so advanced we won't even need a propane furnace any longer.