[Biophysics] Re: reduce amount of exhaled water-vapor?

[bae at cs.toronto.no-uce.edu]

In article <1122200987.042817.66690 at g14g2000cwa.googlegroups.com>,
 <no_child_left_unleashed at yahoo.com.sg> wrote:
>The only cite I can find, says that an "average" person exhales
>approximately two liters of water into the air in 24 hours.  The
>question arises when sizing dehumidification capacity for
>air-conditioning systems.  Of course, you remember  that it costs you
>about 0.3521 KW-hours to condense that amount of water out of the air
>with an air-conditioner.  Which is quite a lot if you have to live on
>what you can generate from wind/solar/microhydro.  Heck, it's a lot if
>you don't, and oil is running $60/barrel
>
>Can anything be done by a homedweller to safely reduce the amount of
>water-vapor he exhales?

Well, if the air temperature is at or higher than 37C and the relative
humidity is 100%, you won't lose any water via your respiratory system,
but that doesn't help either, does it?  Your exhaled air will always be
at 100% saturation at body temperature.  The drier and colder the air
you breathe in, the more moisture you lose when you exhale.

If you're in Singapore, as your address suggests, the outdoor air is
always hot and humid, so ventilation may bring more moisture into your
air conditioned home than breathing will.  Of course, that doesn't mean
you should seal yourself in beyond some reasonable level.

Other sources of indoor humidity are moisture from cooking, bathing,
drying clothing and (if you overdo it) aquaria.  Get a tea kettle with
a whistle, and don't fill it too full.

I'd recommend you look for other places to save electricity.  Turn up
the thermostat on your air conditioner, don't run it when you aren't
home, or perhaps just air condition the room you sleep in.  People
survived without air conditioning until just a few decades ago, and
most still do, even in the tropics.  Hot humid weather is easier to
take if you don't keep exposing yourself to cool dry environments.
Fans are a lot cheaper to run than air conditioning, and can be quite
effective.

Some other places to save are conserving hot water if you have electric
water heating (e.g. use cold water for laundry, hand wash small loads
of dishes, fix dripping taps), don't leave appliances and electronic
equipment on when not in use, and replace incandescent light bulbs with
ones of lower wattage, or with fluorescents.

Keep breathing!