The hydronic system that heats my small office building was installed in 1999. It started out as an oil-fired cast-iron boiler supplying a combination of radiant floor slab on the ground level, combined with some “had to have” radiant wall and ceiling panels on the second story. It’s also set up with a panel radiator and towel warmer. I wanted all these different heat emitters present so that I could provide “show & tell” to prospective clients over the years when I was designing systems.
About nine years ago, I added a monobloc air-to-water heat pump, which now serves as the main heat source with the boiler retained for those really cold (sub-zero) nights, or as backup if the heat pump was down for service. After nine years, I’m happy to report that the heat pump has operated without incident, and it has been exposed to some brutal winter weather. The heat pump also provides chilled water for cooling using a wall-mounted fan-coil in the office space.
