On Thursday, May 14, 2015 at 8:01:16 PM UTC-4, Ralph Mowery wrote:
wrote in message
...
Hi.

I'm finishing my basement (open floor plan, 800sqft, walk-out, full height,
cinderblock walls, no water issues, in New York). It will have 2" EPS
insulation on interior of cinderblock walls, covered with sheetrock. I
have hydronic radiators in main floor of the house (oil-fired boiler) and I
also have just installed a mini-split A/C & Heat pump system for all rooms
of house with capacity for one more unit of 18,000BTU. I'm going to install
that last one to air condition the basement.

My question is: should I rely on that mini-split to heat the basement, or
should I install a new hydronic zone for the basement and install some
baseboards?

I just don't want to be done and then have to tear open walls to install
pipe and baseboards if it's going to be too cold to watch tv and hang out
down there.



My question is how cold does it get where you are at ?

If many days below about 25 to 30 deg F , that mini-split will probably not
be able to make enough heat, especially at 25 and below. For the southern
half of the US they usually work fine in many areas, but it does not get
below 25 for too many days.

If it was above ground, I would agree that would be a
major consideration. But it's a basement. My basement
is about 55F all winter, here in the NYC area. So, it's not
going to take much to keep it warm. Still hyrdronic would
likely have a lower operating cost, especially if it's gas
fired. But then they need the minisplit system for AC
anyway and we don't know what the payback time is for adding
the hydronic would be. I think that's the governing factor.
Also the hydronic lasts a long time, the ms AC not as long.
How much of one of those systems life spans is determined
by usage as opposed to just it's age, IDK, but assuming
usage for heat shortens it's life, then that may be another
factor in favor of hydronic.