🚀 go-pugleaf

Alex Walter <alexw@resumes.com> wrote:

>Nick Pine  . . . Did you start this thread all about Energy Consultants?

I guess so... BTW, there is still an outstanding $10 prize problem... :-)

>I'm a learning "energy rater" for Energy Rated Homes of Colorado with
>a real world question regarding infiltration.   I say I'm learning as
>I've only been dealing with heating and A/C for 30+ years.

So are you one of the opportunists, or one of the shortsighted criminals? :-)

Perhaps you are a farsighted, experienced criminal...

>In the course of performing Manual J (ACCA) heat gain and loss
>calculations I am finding great variances in opinions as to what
>should be used  for infiltration figures.  Do you or any others
>lurking here have experience using blower doors to measure
>infiltration into houses?

I tested and improved two dozen houses around 1975, trying to implode then
with a big squirrel cage blower and a manometer, but haven't done much since,
except look at the numbers in Nisson and Dutt's Superinsulated House book,
and Avis and other housebuilders' numbers. This was interesting work... One
person failed to mention that he had a smouldering woodstove going; one time
the blower ate some window curtains, and almost ate a cat, and I sealed up
one basement so well that the gas heater starved for combustion air...
Strangely enough, I didn't get a lot of demand for my house-sucking services.

These days, it's my impression that when you buy a blower door, it comes
with lots of information on how to interpret the results, with tracer gas
correlations, corrections for building height and windspeed and temperature
(stack effect), and so on. 

>AND if you do what do you/would you use as the infiltration, air changes
>per hour, into a house if you find that a 24,160 Cu. Ft. house leaks
>3,200 CFM at 50 pascals negative pressure?

Nisson and Dutt suggest just dividing the 50 Pa number by 20, so I'd
estimate the natural air infiltratation rate for that house as  
3,200 ft^3/m x 60 m/hr/24,160 ft^3/20 = .4 ACH.

>Using the Manual J detailed infiltration estimate method I come up
>with winter AC/Hr = 0.85 and summer AC/Hr = 0.32 AC/Hr.

Sounds OK to me. I guess a lot of this energy testing is all tied up
with the government and electric utilities now...

Nick