"Solar Flare" wrote in message
.. .
LOL. You forget about the spur runs to other water appliances that are
usually split off and contribute to the thermal drain. The other item
is the plumbing always goes in 90 degree angles if done by a
professional.


Such splits don't have to be filled with hot water to run the washer. They
just present slightly more surface area for cooling. But then, if you
insulate the piping properly, this is a minimal affect. Net result is, you
just have a slightly larger mass of copper to warm up along the way.

Actually, in my plumbing there are a couple of places where two 45 degree
angles, with five feet between them made more sense than a 90 and 7' of
pipe. Admittedly this is rare, but that's why they make 45's. So
professionals can use them when it makes sense.

Cripes! My laundry tub and HW heater are more than 50' (well, maybe
40') apart the way the crow flies, let alone all the take offs in
between.

Again, your 'take offs in between' don't have to be purged of water. They
add very little to the calculation. Less than one extra foot or two thermal
mass to warm up..

You have an unusual house if it's 50' as the crow flies between laundry and
HW heater. My laundry's on the second floor and I've worked out the length
of piping as 27' along the pipe run.

I can fill my machine quarter full of cold before the hot
hits the tub. My ensuite bathroom is even worse as it is over top the
laundry room and has another 20' of pipe to go.


Well, then *your* house is exceptional. Maybe you should do something about
it??

daestrom