Steven Shipley wrote:
>
> Thanks.
> I know that any flammable gas is dangerous so I've always
> wondered why we pipe it into our homes.
It's a calculated risk. Properly handled, it is "acceptably" safe.
> So is it the venturi that makes the gas burn more
> efficiently therefore producing less carbon monoxide?
Yes, exactly. The yellow in the flame from pure natural gas is from
carbon glowing in an area that does not have enough oxygen to burn
completely (to CO2, which is relatively harmless). Some of that carbon
will burn incompletely, to CO. By using a venturi to add air to the
gas, you get the blue flame with relatively little CO.
> And building codes tolerate a small amount of CO in
> a living space?
The OSHA limit is 35 ppm for 8 hours. IMO part of the consideration is
how long the appliance will be used, and whether someone will be awake
to notice either the first effects of CO poisoning (typically headache
and nausea) or the CO detector going off.
BTW, for those who think I'm being paranoid again, some 5000 people are
treated for CO poisoning every year in the US, most of them children
(under 14). Some 200 die.
> I've come to the conclusion that it might be okay to
> burn natural gas in a fireplace insert. The idea is
> that I'd be able to heat up a box made of steel plate
> when the power fails. Sounds like one of those
> flashlight/radios that has a hand crank would be
> better than trying to light the house with gas.
I'm more inclined towards lanterns and candles for light. Yes, these
also emit CO, but relatively small amounts, and I would only use them
for a few hours a day, not while asleep. Your fireplace box sounds like
a good idea.
If you're really worried about extended periods without electricity, you
might look into a generator set (lots of them on sale, since Y2K turned
out to be safe).
Randall
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