Gary Slusser wrote:
"George E. Cawthon" wrote in message
...
Gary Slusser wrote:
"George E. Cawthon" wrote
Gary Slusser wrote:
"George E. Cawthon" wrote
I believe that the 1/2" copper is a direct replacement for 3/4"
iron
pipe. 1/2" iron pipe is totally inadequate for any modern house.
If
it were my house I would replace the larger runs with 1" or 3/4"
copper and the branch runs with 3/4" or 1/2" copper. Follow what
others said about the type of copper pipe
Actually, 1/2" and 3/4" copper or galvanized has the same OD
although
the ID
of L and M copper will be only slightly larger than galvanized and
roughly
about the same a K copper.
But.... with water conservation fixtures, what's the need to go to
so
much
larger tubing until we figure the peak demand that's needed for the
system?
You do that by adding up the max gpm of each fixture or use the
fixture
count method. And in new construction and many repipe jobs,
homeruns,
like
running Romex, using PEX is being used with excellent results. No
fittings
except one on each end of the run and each run is valved at a
central
manifold.
Gary
Quality Water Associates
www.qualitywaterassociates.com
Bulletin Board www.qualitywaterassociates.com/phpBB2/
It isn't the size it is the smoothness of the pipe wall that makes a
difference in flow. Sizing pipe based on the flow needed is driven by
economics. As a homeowner, especially a do it yourself homeowner,
economics is only one factor and may not be the most important factor
for me. I would use a larger size of pipe to reduce flow noise, a
larger slower fan and larger ducts to reduce air noise, a larger size
wire to reduce voltage drop, heavier floor joists and subflooring for
greater solidity, thicker outside walls for comfort and sound control,
etc. If I eliminate the labor cost, and since labor is a major cost
in any construction, I can devote more capital toward premium
construction elements.
Problem is George you were giving him advice, not speaking as to how
you'd
do it. But I agree with you, you're not a plumber. You also don't know
what
you're talking about IMO when it comes to sizing water line. And if it
weren't so late, I might prove it but it is late. And I doubt you'd get
much
out of it anyway. I'd really like to hear more about the smoothness and
less
water noise in larger pipe though, I see a full pipe regardless of the
ID or
smoothness so there will be no water movement noise. There's only one
chance
to get the pipe sized correctly, and that's at the beginning when sizing
it;
regardless of smoothness or whatever, it's the ID of the pipe for the
job it
has to do, and that's delivering the amount of water the system needs.
Good grief! No water movement noise? What the hell is that about,
how do you get water out of a faucet if the water doesn't move? I
suggest that you look at a 2 foot wide stream that is flowing 30 cfm
and then a 10 foot wide stream flowing the same amount and listen to
which one is making more noise. The same principle applies to flow in
pipes.
You seem to think one size of pipe is correct. Not true and you know
it. What is true is that a pipe below a certain size won't deliver an
acceptable about of water. Anything above that will deliver an
acceptable amount of water. It takes about 1.5 hours maximum for the
slowest reader to compare several sources as to normal and minimum
acceptable sizes of pipe. There is about as much science in sizing
pipe for a single family dwelling as picking out the size of the
family car.
Gary
Quality Water Associates
www.qualitywaterassociates.com
Bulletin Board www.qualitywaterassociates.com/phpBB2/
So I read a book and that says 1/2" copper is a flow substitute for
3/4" iron. Actually several books say that. Picking a size for a
water line in a single family dwelling requires about as much
information as you can get in about 1/2 hours of reading for a slow
reader. Any good book will tell you what sizes are acceptable
throughout the house. There is no single size that is correct. There
a sizes below a minimum that will not be satisfactory. Hell, if you
want the fast way just look at the outlet from the meter and use that
size throughout the house; got a 1" supply from the meter,then use 1"
throughout the house. While that is obviously overkill If the inlet
from the
George we are talking a full potable water pipe, and probably cold water at
that, an enclosed water line. And certainly not some open ditch. We also
aren't speaking of the water as it exits the faucet or fixture. where the
noise is caused by the water splashing or the aerator makes noise.
I know what we are talking about. We are talking about the noise of
water running through pipes. I've lived in houses with noisy water
lines. Most noise is caused at valves and then transmitted to the
walls through the pipes. And, the largest noise makers are usually
the valves associated with the water closets. The second noisest in
my experience is the outside faucets. But any constructed point in
the water line is a potential noise maker. And no, we aren't talking
about the noise of water splashing. We are talking about the kind of
noisy you hear when you are 30 or 40 feet from a fixture and separated
by several walls.
Yes one size pipe is correct for the specific house it is installed in.
Science... or actually math, is applied to find the (acceptable) velocity of
the water in whatever pipe size we use. The standard acceptable velocity is
not more than 6-7ft/second in whatever size pipe to be used. The velocity is
dictated the size of the pipe. The velocity is dictated by the size of the
pipe and the PRESSURE applied to whatever size pipe we select but there's
only one size correct for that specific water system. Only one size is
correct per installation because we have to base the pressure used on
open/running fixtures gpm requirement to calculate the velocity.
That's pure BS. There is a MINIUM pipe size based on acceptable flow
rate. Even you admit that, by saying you want to maintain a water
velocity of 6-7 feet per second, because the way you reduce velocity
is by increasing the size of the pipe. There is no MAXIMUM pipe size
unless you want to base it on pure practicality or economics. Most
fixtures have short, small (1/4" or 3/8") pipes between the fixture
and the supply line that determines the flow through the fixture, or
the fixture itself may have smaller openings that determines the
maximum flow or the supply valve may be the flow limiter. It doesn't
make any difference to the flow out of the one fixture if the supply
line is 1/2", 3/4" or 1 inch. Unless, you have several fixtures
flowing which reduces the pressure and then you want the supply line
to be larger.
There is no single size correct for water pipe any more than there is
a specific size for a bed room. If you like a big airy room, then
make the bedroom big. If you like a lot of flow even when other
fixtures are open, then use large diameter pipes. I doesn't make much
sense, unless you have a long run, to use pipe larger than your
metered supply. And yes, here we have an option of 3/4" 1" and 2"
meter supply.
That part about 3/4" iron/galvanized and 1/2" copper... yes, you'll always
get more water through 1/2" copper than a rusted up, full of encrustation
filled galvanized pipe, but not a clean one. With a clean one, you get more
water by about 2-3 times more with the 3/4". Prove me wrong if you can. And
it 'is' more the size of the pipe than the smoothness of the pipe, and
plastics are about the smoothest you can find; hard water scale does not
stick to the inside of plastics, nor do they rust or corrode which causes
roughness.
Hey, I don't know if it is true or not but several books on plumbing
indicate that 1/2" copper will replace 3/4" iron because of the
greater flow rate through copper and they weren't talking about rust
filled iron pipes. I do know that iron pipe, especially when you
consider the elboes and other connectors can be extremely rough
compare to copper.
Gary
Quality Water Associates
www.qualitywaterassociates.com
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