On Feb 15, 1:13*pm, Shaun Eli wrote:
Seems like it adds a bit of heat, at the expense of leaving the shower
with dirty feet. *Why are you closing the drain when you shower?

To prevent warm water going down the drain. Having just spent anywhere
from 5 to 8 kilowatt hours of electrical energy heating up the 40 US
gallon hot water tank; seems wrong to now let that hot water (mixed
with cold water to a suitable shower temperature) run straight down
the drain!

Someone else here seems to think drain is clogged, it is not. We are
'holding' the water deliberately in the tub; by leaving the plug in
for an hour or two after showering.

This is a very small town our effluent drains down into the sea with
very little treatment. But, in part, what got us wondering was that;
in a large city some manholes and drains actually steam in very cold
weather. So that heat was/is being wasted into the ground or all
outdoors.

Same as the wasted heat from our car engines. Don't know what the
figure is but is; but only 30% or something of the gasoline actually
goes into driving the car?

Also sometimes you will see 'homeless' people sleeping on top of the
exhaust gratings from buildings which are putting out considerable
amounts of warm air. All that heat, which has been made by the burning
of gas, or oil, or electrcity. Although in some cases heat pumps also
used.

And yes the saving per shower, or the less often, full bath tub, is
very small. The cost of the heat 'lost' down the drain being probably
of the order (in our case) five to eight cents per shower? For us (1.5
persons), only $30 to $50 per year.

So could one estimate, that in a family of say five with a proclivity
to take long showers and/or baths; the saving, by allowing the warm
bath water to slightly add warmth to the house could be of of the
order of $200-$520?

If so that's around one dollar per day which is what some poor
families this world try to live on!

The present credit and economic crunch brings some of our energy
wasteful methods to mind. And there are apparently now houses that are
so well insulated and have solar cells etc. that they actually make
more energy than they use for the house itself. However don't think
those houses are in very cold or hot climates etc. or the extra
investment cost needed?

BTW it only takes a moment or so to clean off the bath tub and it
takes a few litres of water; which do not need to be hot as shower
water (cold or oller will do) so that's a non issue; merely to prove
that warm water should NOT be held in bath tub. Must calculate the
heat lost from the volume of the exhausted air from the fan, though.