On Tue, 23 Nov 2004 05:02:10 +1100, "Rod Speed"
wrote:


"Gary R. Lloyd" wrote in message
...
On 22 Nov 2004 08:11:30 -0500, wrote:

Gary R. Lloyd wrote:

ASHRAE's "15 cfm per occupant" standard is designed to avoid health issues.
Smoking, radon, and so on may require more.

For a family of four, that comes to 60 CFM.

You have stated that miners have been shown to pass out at 5 CFM per
person. For our family of four, that comes to 20 CFM.

These 19th century coal-mining experiments were an early basis
for ventilation standards.

You advocate the Canadian model, where the passive leakage is reduced
to 2.5 CFM. Then you would make up the difference by forced
ventilation.

Sure. This also works in most of Europe, and in many books on efficient
home design, eg The Superinsulated Home Book, by Nisson and Dutt
(Wiley and Sons, 1985.)

Is this a fair representation of your position?

Sure. It may be time now to look for better solutions instead of problems.

What are the pros and cons of tighter construction with forced
ventilation versus passive ventilation (leakage), assuming they
both result in roughly the same amount of ventilation?

The obvious pro with tight construction and active ventilation
is that you have real control over the ventilation and can vary
it depending on stuff like CO CO2 and humidity levels.

The only real downside is that you may need some form of
small UPS or internal battery power or failsafe to an automatic
shutter etc if extended periods without power are possible/likely.

I'd personally just have a decent warning system with a completely
unambiguous warning message where its clear what is warning about.


Another real downside is price. What would be the payback?

Gary R. Lloyd CMS
HVACR Troubleshooting Books/Software
http://www.techmethod.com