Best heat for 2-flat front entry at staircase bottom?
After 116 hours, we finally broke the zero-degree F ceiling here today. About halfway into the cold spell, we heard a bang from the foyer and knew the hot water radiator out there had burst. For a hundred years, there’d been a radiator there, next to the front door, in the very NW corner of two outside walls, on the highest point in SW Minneapolis. My fiancée lives with her kids on the ground floor of this two-flat owned by her parents, and I do a lot of work on the building for them. I shut the inlet valve, removed the radiator, and capped the return, whose course back to the boiler runs for 18 feet along a very cold rim joist.
The radiator survived as long as it did, I suppose, because until this winter, the whole building ran on a single ground-floor thermostat, ensuring that there was hot water coursing often enough through that unit out in left field. Last summer, the watercourses were split, and the hulking iron boiler was replaced with a HE box the size of a footlocker.
I’ve been discussing the next step with the folks, and intuitively, I think a change to a wall-mounted, fan-driven heater in that 50-square-foot entry way is in order. The staircase to the upstairs flat is open, there are two good-sized windows on the north and west walls along the stairs, and there’s no heat on the second landing. From foyer floor to staircase ceiling, it’s about 20 feet. I know there are mini-split water heaters that can operate independently of the main boiler, but that seems like an expensive installation for an area that isn’t a living space.
Is my intuition getting warm? Thanks in advance for any and all advice.