Opinions about 2 part heat pump hot water heaters (e.g., Sanco 2, Sanden)

I have wanted a heat pump hot water heater for a while, but the closet it fits in is just too small for any of the existing (1 piece) units.

Just recently, I’ve noticed that there are now 2 piece units: the inside part is only a storage tank, outside is the heat pump unit. Cold water (or cold-ish) flows from the tank into the outside heat pump where it is heated, and returned to the tank as hot water. This design might actually allow me to get a heat pump water heater.

I’ve found 2 companies (that might actually be the same company) that supply these types of units: Sanco and Sanden. Is anyone familiar with these companies or these 2 piece water heaters? The Sanco unit I saw had an “Energy Guide” label saying yearly cost estimate to run is $127, which is excellent. It had a 43 gallon storage tank, and a first hour rating of 69 gallons. The heat pump is rated to work all the way down to -15 degrees. The Youtuber Matt Risinger (who makes home building videos) mentioned that he installed a Sanco unit in his house.

Some of the questions I have:

  • How loud is the outside heat pump unit?
  • Have you actually used / installed one? What is your experience with it?
  • Do other companies provide 2 piece units?
  • Are Sanco and Sanden the same company?
  • If you have one, how did you order it, and who installed it for you?
  • Do you know anyone who has had a bad or a good experience with it?
  • What criteria would you use to judge a unit like this?

Thanks for your opinions,
J.

I’ve just learned that Sanden is actually the name of the company, and Sanco is the name of their heat pump water heater.

J.