Natural Resources Canada uses the following program to calculate rebates for
energy efficient home upgrades.

Download from:
http://www.buildingsgroup.nrcan.gc.c.../hot2xp_e.html

According to the technical report from this software, a one-story house with
a full basement 43' x 43' exterior dimensions with a floor area of 1500sqft
on the main + another 1500sqft in the bsmt results in the following heat
loss values at 19F on the north west coast.

Base values:
==========
Orientation: west
Window distribution: even, 15%, metal, single
Cathedral roof: R12 attic
Main floor walls: R12 on 2x4 wood
Basement walls: no insulation, mostly below grade
ACH @50kpa: 10.35 (ACH = air changes/hour)

Heat loss = 57k (seems low to me as most HVAC contractor recommend 80k or
more)

Upgrades: (cummulative):

HL
49k; Low-e, double pane, vinyl windows
37k; Add R20 to bsmt walls
32k; Upgrade attic to R40
28k; Reduce ACH to 4.5


It gets even better, annual fuel consumption is reduced from 215 million btu
to a mere 81, almost 2/3's. Can anyone here verify these calculations
empirical evidence?

Martik wrote:

Natural Resources Canada uses the following program to calculate rebates for
energy efficient home upgrades...

Base values:
==========
Orientation: west
Window distribution: even, 15%, metal, single
Cathedral roof: R12 attic
Main floor walls: R12 on 2x4 wood
Basement walls: no insulation, mostly below grade
ACH @50kpa: 10.35 (ACH = air changes/hour)

Wow. Does the house implode? 50kPa is 1044 pounds per square foot :-)

Nick

edee em wrote:

"Wow. Does the house implode? 50kPa is 1044 pounds per square foot :-)"

Only if it's absolutely tight, of course. I just had this test done and my
place was rated as very air tight but when the blower went on, the draft in
places could part your hair!

They only test to 50 Pa, not 50 kPa.

ACH @50kpa: 10.35 (ACH = air changes/hour)

That's about 0.5 ACH of natural air leakage, an airtight house,
by US standards, but a poor submarine :-)

Nick