On Fri, 26 Feb 2010 12:32:19 -0800 (PST), "js.b1"
wrote:

On Feb 26, 7:43*pm, krw wrote:
A extra gallon of water would be quite welcome in most
houses in the heating season.

In the UK the opposite is preferable.

Even in Alabama it's so dry in the Winters that many run humidifiers.
Anytime you heat air the RH drops. Heat air 50 degrees and lizard
skin isn't unusual.

Kitchen:
- 75m3/hr extractor over a cooker/hob
- 150m3/hr extractor if say a wall fan

Water extraction or ventilation? That's significant air exchange
right there.

Bathroom:
- Similar water extraction required


UK houses very quickly suffer from damp & condensation.
If you try to heat an older house via an LPG portable heater the
airflow requirements for the burner and to avoid condensation will
almost negate the heating effect (ie, you will need huge amounts of
LPG to compensate making the seemingly cheap heating very much more
expensive).

UK construction:
- Double solid brick or similar (1930)
- Brick-Brick Brick-Block cavity wall (1950)
- Brick-Wood cavity wall (1970)
- Brick-Wood insulated cavity, airtight (2000)

That's not the point. Heating air reduces its RH. It's not unusual
to have an interior RH under 20%.