> I’ve tested it down to around -5 degrees (f), and it was 100% able to keep the house above 63 degree (f).

Some customers will accept that. Most will not. Reddit is not a particularly representative sample of the entire market.

If you read just a smidge of the context, it's a sizing issue, not a capability issue.

63 when it’s -5 out seems totally fine. More than fine for much of the US.

Maybe totally fine for you. But that will not be "totally fine" for much of the US when they are expecting to keep their house at 72 degrees and the new technology they got talked into can't do it.

The tech has limits and cold weather states can't avoid that or the reputation will get really bad and the tech will fail.

I'm not sure if you've lived in prolonged -15F areas, but many conventional heating systems struggle too... especially in poorly insulated houses. People often have wood stoves or other ways to compensate.

ok, Reddit is not representative. what qualifies you to speak for what customers will accept?

I spent 5 years installing and maintaining A/C equipment for residences and a few small commercial locations.

and if you believe that heat pumps do not work below freezing temperatures, you are part of the reason why misinformation keeps spreading. You should know better. You should be ashamed to be spreading straight up lies.

Chicago days under -15°F since 2015:

  Jan 18, 2016 -21°F Coldest day of that winter
  Dec 19, 2016 -21°F Early-season Arctic outbreak
  Dec 27, 2017 -19°F Part of a prolonged late-December cold wave
  Jan  2, 2018 -23°F Deep freeze to start the year
  Jan 30, 2019 -30°F Coldest Chicago temp since 1985; “Polar Vortex” event
  Feb 14, 2020 -18°F Valentine’s Day Arctic blast
  Feb  7, 2021 -21°F Mid-winter cold snap
  Dec 23, 2022 -23°F Pre-Christmas Arctic front
  Feb  3, 2023 -17°F Last occurrence to date

So basically every year.

edit: downvoted for noticing that it is cold.

What's relevant is not how cold it got on the coldest day of the year, but how warm it got on the coldest day, and how long it stayed cold. If the daytime high is mild enough that an undersized heat pump can keep the house at 72, it will take time for that house to cool from 72 to eg. 63 when the temperature drops overnight. And since the heat pump is still trying to keep the house warm, it'll take a lot longer for the house to cool off than if the heat were turned off entirely.

It makes sense but I just wasn’t willing to trust that with my checkbook, you know? There’s how it’s supposed to work on paper and then a reality where I’m stuck with it.

The regular AC and gas furnace combo works and is cheaper so I stuck with that.