[A/S] Asphyxiation

["nickcrowhurst" <NickandSandra@xxxxxxxxxxx>]

I've been worrying about some of the posts I've read about using 
portable heaters and blocking up ventilators during cold weather. 
When I was a kid I slept in a small unventilated cabin in a yacht, 
and I used a candle for a light. I woke up one night, having fallen 
asleep with the candle lit. My breath was coming very rapidly and 
making rasping noises. This was very frightening, and I crawled out 
of the cabin door to be met with fresh air, at which point I realised 
what had happened. My breathing and the candle flame had used up most 
of the oxygen. Some years ago I walked into a room on Christmas Eve 
to find a mother and daughter sitting in armchairs watching TV beside 
their gas fire. They were both dead. So I guess I'm a little paranoid 
about this, but these are some of the rules I observe, especially in 
our Airstream and in the cabin of our sailing yacht:-
1. Any furnace or catalytic heater should take in air from outside 
for combustion, and exhaust the combustion gases to the outside. The 
Airstream furnace is a beautiful piece of work in this repect.
2. No pilot lights to be alight within the trailer.
3. Ventilation to be used every time the oven or hob is used, even to 
boil a kettle. An air intake low down and an exhaust up high is 
ideal, but difficult to arrange in an Airstream in cold weather. I 
use the exhaust facility on the A/C, open the bathroom vent, but keep 
the sliding bathroom door shut. This has an air gap at the bottom, 
but not at the top. Perhaps a closeable vent in the floor would be 
ideal.
4. No decorative candles alight in the trailer. I fail on this rule! 
My wife loves to have a huge bottle-candle alight in the evenings, 
and I bow to this. (I have learnt to do exactly what women want. In 
my family there are my son and I, and ELEVEN women!) When she puts 
the lid on the candle at the end of the day, the flame is extiguished 
within a couple of seconds.
5. Even in cold weather, keep the bathroom ceiling vent slightly open 
at night. Not much use on its own, but I feel happier.
 So, any burning or breathing uses up the oxygen which keeps us 
alive. Carbon dioxide is the product, and trees live on this, but we 
don't. Poor ventilation for heating flames can cause carbon MONoxide 
to be produced. This is fatally poisonous, colorless and odorless. In 
our Airstream I have a smoke alarm, a carbon monoxide alarm, and an 
LP gas alarm. However, I know of no Carbon dioxide alarm, and this 
concerns me. A paranoia shared is a paranoia halved, so thank you 
all! From Nick.