I'm sure someone will give you a better answer, but what you're looking
for is "Partitions". HAP has no idea where each room is relative to the
next one. You use the Wall and Ceiling Partition tab on the Space input
window to define a shared wall next to a space that is unconditioned or
at a different temperature. You define the Wall or Ceiling U-value
between the two spaces and then you set the max and min temperatures for
the neighboring space relative to two outdoor temperature extremes. HAP
then linearly calculates the neighboring space's current temperature at
any point in time base on the outside weather conditions at that point
in time.

For an unconditioned or partially conditioned basement below your
conditioned floor, you do a similar input using the Floor tab and
setting it to Above Unconditioned Space.

Good luck. I've been using HAP for 5 years now and it's been quite a
learning experience.

Matt Scott

N.E. Fisher & Associates, Inc.

329 East Second St, 2nd Flr

Boyertown, PA 19512

e: mscott at nefisher.com

p: 610-369-3190

f: 610-369-3194