"Tony Hwang" wrote in message
news:ja6bh.392256$R63.206259@pd7urf1no...
Mike wrote:
This summer, I upgraded my walls to R20, attic to R40, replaced metal
single windows with double low-e argon vinyl, replaced all wood doors
with insulated steel, air sealed the house and replaced a 30 year old
120k gas furnace with a 75k condensing unit. The old furnace used to run
every 5 out of 15 mins at 0C, now it runs 10-15 mins every 3-4 hours.
Something doesn't seem right here as my neighbors runs 2-3 times per hour
and it's a 100k furnace in approx the same sized house with similar
insulation (maybe 20% less) I have my tstat set to +/- .5C and CPH
disabled.



Hi,
Size and style of house? The more insulation, the better. Only concern
will be fresh air supply.

1600sqft on top floor plus a 1400 sqft finished bsmt 2ft below grade in
front and 6 ft in the back. I believe insulating and airsealing the
uninsulated foundation walls made the biggest difference as the bsmt is now
7C more warm than last year. This also significantly reduced the "stack
effect", cold air infiltrating thru the bsmt towards the warmer upper floor
of the house. The heat loss model I used also supports this observation.