On Dec 8, 4:45*pm, wrote:
On Thu, 8 Dec 2011 05:37:09 -0800 (PST), "





wrote:
On Dec 8, 8:27*am, Jim Elbrecht wrote:
"Roanin" wrote:

-snip-

Then decide whether you're going to keep it warm all the time, or if
you're going to go out there when it is -20F & hope to have a party in
an hour.

Actually it is just a room that I want to make comfortable when I go out
there to do whatever. Probably will not be out there when it is -20F. Who
knows what I will use it for. Plans are always changing.

In that case- throw out all the BTU factors and whatnot, and put a
torpedo heater there to bring you up to comfort level. [100k wouldn't
be overkill]

Or look into infra-red heating. * * * Then you need to pay more
attention to the surfaces in the room-- color and material.

You don't say what kind of fuel you'd prefer. * That might affect how
much it pays to just over-build to capacity.

Jim

I don't know about 100K BTU, which is enough for a whole
house. *But I would factor in that you most likely want it to
be able to raise the temp quickly. *Scenario being you keep
it off or at a low temp and turn the temp up on the random
times you decide to use it. * That's a different usage than
what the standard calculations are based on. * For example,
if you size a whole house system, you should wind up
with BTUs that are slightly more than required to maintain
the temp on the coldest day. * However, with that sizing, if
you let the house get down to 40, it would take a very long
time to heat it back up, even when it's only 30 outside.
So, I think you need to be large enough to heat the place
quickly. *On the other hand, you don't want it so large that there are
short cycles, wide swings, etc.

*The SMART way to do it is with multiple units. If you need to come up
to temp quickly, you pull out all the stops - and if you just want to
"keep" it warm you use only a fraction of the total capacity. Easy to
do with electrics, and not hard to do with gas, oil, or propane if you
install a minimum of 2 units. One relativly small unit to maintain
temp, and one "big muthu" to warm up quickly.- Hide quoted text -

- Show quoted text -

Maybe I'm missing something, but I don't see multiple gas
or oil units being smart. It's one 280 sqft room. Just get one
that's sized to heat
the room from being cold when unoccupied to 65F in
a reasonable time, say 30 mins to an hour?
With electric, being easier to install, no service, cheap, etc,
then I could see using multiple units, primarily if it's desirable
to heat the whole space more evenly. But for a shop, maybe
all he really cares about, at least for quick heat up, is one area
around a workbench, etc. In which case one electric could be
fine.