Some pictures of the corner of my
outbuilding shop that could become a (sort of) cCube.
This shows the corner the cube would be in
(SW). The arrow lines show the area to be used.The west wall of the cube would include the
first window. The south wall would include an 8 ft width
of the collector (two 4 ft bays).The vertical white glazing supports are 2
ft apart -- every other one is the end of a collector bay, and is a solid
bulkhead.The active area of each collector bay is
46.5 inches wide by 93 inches high.Looking at the south wall from the inside.
The cube would end just to the left of the
generator.The width inside the cube would be 114
inches.The bat insulation is R19 FG.The west wall.The window is 36 inches wide by 60 inches
tall -- double glazed, low e.The north cube wall would come in just
where the picture edge is -- 12 inches to the north of the window.West cube wall width would be 91 inches.The ceiling is 14 inch deep engineered
joists. The spacing is uneven in this area due to the stair up to the
top level.Above the ceiling is a full height loft
level -- the roof line of the loft is insulated with R19 FG bats. The
loft has windows that could be opened to keep the temp somewhere near
ambient.Ceiling height (slab to bottom of joists)
is 114 inches.The floor is a 4 inch (more or less) thick
slab with thickened edges -- no insulation. So, the slab in the cube
area would probably require insulation on top of it to prevent a large heat
loss.South wall area (incl collectors) =
(114*114)/144 = 90 sqft North wall area = 90 sqftWest wall area (including window) =
(114*91)/144 = 72 sqftEast wall area = 72 sqftFloor area = (114*91)/144 = 72 sqftCeiling area = 72 sqft.Total surface area = 468 sqftSo, about $1000 of insulation to add
about 4 inches of polyiso everywhere.Tentative construction thought:(idea is to keep the 4X8 panels as intact
as possible for reuse)- Ceiling: attach polyiso to bottom of
ceiling joists using washer screws of some kind -- two layers with crossed
joints.- West wall (already has R19 FG): Maybe
only 1 layer of 2 inch polyiso screwed with washer screws on top of the
studs. Cut insulation around the window so that it remains a window.- South wall -- maybe fill in stud cavities
with R19 FG, then add 1 layer of 2 inch polyiso inside the studs?- East wall (added): Screw 1
horizontal 2X4 to the bottom of the ceiling joists. Temporarily anchor
a 2nd 2X4 to the floor. Add a couple vertical studs between the top
and bottom horizontal studs. Place the rigid polyiso panels against the
outside of the 2X4's -- first layer with long way running North-South, 2nd
layer with long way running vertical. Since the ceiling is 9.5 ft
high, part panels will be needed above the 8ft.Maybe tape seams?- North wall (added): Do it the same
way as east all, but add a door -- maybe just a removable 4X8 panel?- Floor: Just lay 1 or two layers of
2inch rigid on the floor, and lay some half inch CDX over the areas that get
walked on.-----------Is this enough insulation/collector area to
maintain 70F?Heat loss might be about:(468 sqft)(1F)(1/R28 BTU/hr-sqft-F) = 16
BTU/hr-FFor an average 25F outside and 70F inside,
(70F - 25F)(16 BTU/hr-F) = 720 BTU/hr, 17K BTU/day.Not counting infiltration or greater loss
in window area.Sunny day gain for 60 sqft collector might
be 48K BTU ish.Seems like it might be in the general
ballpark?Gary January 30, 2010