Heat pumps are very common in the US. That part isn’t really a challenge.

Heat pumps are super common, in the southern US I would be willing to bet you can't build a house without one, even geothermal is a heat pump.

I don't get what this startup is offering. Heat pumps are common and readily accessible, I can walk into lowes and buy one today and they can arrange a contractor to do the install. It'll be a lot less expensive this this setup.

If your business plan starts with "X is rare and hard to find" and X is actually extremely common, you're not going to be successful.

In the South-East US we've used Heat Pumps for at least 35-40+ years. Probably longer, I'm just lowering the number because I was a kid and don't know when they became the norm exactly. We don't have strong winters here so even the older heat pumps were fine with keeping houses warm. And we had/have resistive electric heating to supplement if the temp dropped too fast or too low.

You're right, heat pumps have been around for a while, but they're only at 15% market share across the whole US. The Southeast, for a few different reasons, has the highest market share. (1) It doesn't get that cold, and magnitude of heating/cooling loads are close enough that single stage equipment provides an OK experience. (2) There's very little natural gas infrastructure.

Cold weather heat pumps have recently become popular and enable increased adoption in the northeast, and the fact they're so efficient means they're competitive even in areas with a lot of natural gas infrastructure.