CSST?
I've been toying with the idea of putting an NG fireplace or heater on my 1st floor (above ground, on slab). That floor is not true living space, mainly garage, foyer, and an unfinished area we refer to as "the basement" (laundry, storage, and my shop). The thermostat is on the 2nd floor, so this 1st floor area gets cold in the winter. We use the kerosene heater to warm it when we feel the need, but since we have NG service to the house (heat, water, and cooking), it seems running a line to the foyer for one of those wall-mount heaters would work well. Maybe even put one in the foyer and one in the "basement" for spot heating as needed.
Chris