Gary Slusser wrote:
"George E. Cawthon" wrote
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.
I've been around a lot of water pipe and haven't experienced the noise you
have.
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.
Which goes to your suggestion of 1/2" to replace a 3/4" galvanized water
line; the basis of my reply to this thread.
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.
I said the selection of the pipe size is dictatd by the velocity and
velocity is dictated by the pressure the system requires.
There is no MAXIMUM pipe size
unless you want to base it on pure practicality or economics.
This is a DIYer you're advising, Why would he want to buy and install a
larger pipe than he needs?
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.
True, and you add them all up at maximun flow rate and figure what peak
demand flow rate the pipe size has to provide.
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.
Listen to what you've just said: Unless what? And then you need what? More
pressure? The problem is you don't have enough flow at the pressure the
system is operating at. Which goes back to your statement that his 3/4"
galvanized can be replaced with 1/2" copper with 2-3 times less WATER
delivered. If he does that, his velocity will be too high and that causes
water hammer damage to the entire system. Then he's out buying and
installing water hammer arresors BUT, he can't get more water without
increasing his PRESSURE. Which again then increases his velocity. Following
your advice, he's got a too small pipe. And going to 1" is a waste of money
and time to drill out joists etc. to get it through where 3/4" galvanized
was used previously. The same size PEX, CPVC or copper is the right choice
pipe size. Go look it up in something other than an old book. Find flow
rates of various materails. Read up on velocity and water hammer.
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.
I said specific to the building, that's not a blanket type statement
applying to all buildings.
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.
Look, I'm replying to what you said and I know the next larger ID pipe
provides 2-3 times the water volume than a 1/2" pipe given the same
pressure. Telling this guy with the question Is bigger better? to go with
1/2" copper when he has 3/4" galvanized (steel) due to a change in the
material is wrong.
I didn't say that. Go back and read what I said.
Go here and check out the result of your 1/2" copper to 3/4" steel and see
if you can visualize the additional water you get out of the 3/4" steel as
compared to 1/2" copper when all esle is the same. Also check out the
velocity difference and the blurp concerning velocity on the same page.
http://www.connel.com/freeware/flowcalc1.shtml
Fine.
And then go play around this page.
http://www.geagolf.com/GEA%20Pressure%20and%20Flow.html
And if you need more information, let me know.
Gary
Quality Water Associates
www.qualitywaterassociates.com
Bulletin Board www.qualitywaterassociates.com/phpBB2/
One last comment as we may be cross talking. First, my main concern
was that the idea that one specific size is right, is just not
correct. Larger pipe may cause other problems but it doesn't cause
flow problems. Hey, it was me that said bigger is better.
Ok, so you disagree with the 1/2 copper replacing 3/4 inch iron
pipe. Ok, that's fine. It really doesn't make any difference to the
discussion because (a) he now has 1/2 iron pipe and you know that 1/2
copper will flow better than 1/2 iron pipe. And (b) I said that if it
were my house I would use larger pipe.
I think you just want to argue. So look back through the stuff, I
never said to replace 3/4" iron pipe with 1/2" copper.