On Thu, 16 Dec 2010 08:16:19 -0800 (PST), "hr(bob) "
wrote:

On Dec 15, 5:20Â*pm, wrote:
On Wed, 15 Dec 2010 22:50:42 +0000 (UTC),





(Larry W) wrote:
In article ,
a poster wrote:

...snipped...
As the Idjit who filled in the orifice and then redrilled it, I can
assure everyone that I did calculations on what size orifice I needed
to get a certain BTU flow. Â*I did this 20+ years ago and don't
remember the details any longer, but it was not strictly based on
cross-section of the orifice opening, but also included the effects of
friction of the gas with the orifice walls.

.... It may not
meet some PhD type of analysis, but it cut down the gas consumption
and we stay warm on -10 degree nights and days so I guess Â*I did
something right.

Most likely the unit was originally greatly oversized or grossly inefficient
for your tinkering to have worked so effectively.

MOST 30 year old and older units were grossly oversized.- Hide quoted text -

- Show quoted text -

It's not the unit was oversized, the unit was oversized for the
particular size house or heating application.
What else did you think I meant? Pretty obviouse it is "oversized
for the application" because if the same furnace was installed in an
arena it would be grossly undersized.

The tendancy was to go with "bigger is better"