Long plumbing run - pull out copper for pex replacement? - Page 2

Daox · 12-04-12, 07:45 PM

No, I haven't noticed any hydraulic noise. I'll listen more carefully for it next time I use the shower. I'm not sure if there is a water hammer suppressor installed on that water line. My guess would be no.

Exalta-STA · 12-10-12, 05:52 AM

Just curious, how many feet of copper piping did you remove and where is it now?

Daox · 12-10-12, 06:56 AM

I'd estimate roughly 20-25 feet of copper. Unfortunately, none of it is in reasonable lengths since I had to cut it up into smaller lengths just to remove it. Most of it is cut up and laying in a scrap pile I have. There is still ~9 feet in the wall that I couldn't get out because it was anchored to the studs and I didn't want to open the wall up.

Daox · 12-30-12, 01:38 PM

Just following up on this. I haven't noticed any hydraulic noise even when listening for it.

FortyTwo · 12-31-12, 10:46 AM

I replaced most of my basement plumbing and first floor runs with Pex (from copper). It made a significant difference in the kitchen, especially for the dishwasher. I had a high efficiency / low water consumption bosch dishwasher and it never drew enough water from the water line to get actual hot water. Now I run the kitchen faucet a bit to rinse dishes, and get the line hot before starting it. Also- I think that water hammer is greatly diminished with Pex- as it has some flex and give that rigid copper doesn't. I am so happy with Pex- I'm thinking of redoing it all again in a few months as a home run system, with all the shut offs and lines in one place in the basement. It is ridiculously fast and pretty cheap to use, and I have_never_had_a_leak.

Snail · 01-07-13, 04:57 PM

I've just replumbed my new-old house with small-diameter plastic piping. Longest pipe run from the central in-line condensing gas water heater is about 12 metres (40 feet). I just completed the wiring to the heater a day or so ago. The hot water comes through faster than the much shorter 3/4 inch copper pipe runs at my existing house and there is no propblem with pressure loss in this mains-pressure system.

I ran some calculations on insulation. Given that you are going to loose all the heat in the pipe fairly quickly, regardless any insulation and given that even in a windly crawl space and with a 10 meter run of copper pipe the rate of heat loss from the hot water in the pipe to the air is at least an order of magnitude lower than the 10 to 30 kilowatts being supplied by your heater or cylinder whilst the tap is being run, complete pipe insulation is a waste of time and money in my climate. If you had a freezing blizzard passing the pipe and you were using the tap at the end of a long run at frequent intervals it just might be worthwhile I guess. So do the calculations first!

If you have a hot-water storage cylinder, heat will be conducted from the cylinder along the pipe at all times, not just when water is flowing, So in this case, you need to insulate the pipe from the cylinder for a meter or two, so that the loss from this cause is low compared to the general losses through the cylinder lagging.

Peter

Snail · 01-07-13, 05:42 PM

Having now reread the post on insulation, I'm properly embarrassed. Of course you need to insulate pipes where they might freeze, hot or cold, plastic or copper. My excuse is I'm now in a climate where that isn't an issue, unless the pipes are completely exposed, hence I misread the earlier post. (Also I've just come back from field work in Indonesia to an exceptionally hot summer Christmas at home. Freezing was a distant memory to me!)

However, I'm curious now. I used to have a house where we did get freezing temperature, but usually only overnight and never for more than a day or so. What happens to those of you who live in climates where freezing temperatutes last for days, or even months? Surely, in that case, no practical amount of insulation will stop eventual freeze-up? If you are lucky enough to go for a winter holiday, what happens when the taps are not used for a significant period? Even pipes which are within the conditioned envelope must be at risk if the house is unheated. Ouch!

Daox · 01-07-13, 07:08 PM

Well, we never leave the houses totally unheated. We just turn down the temperature when we're away.

Snail · 01-07-13, 08:05 PM

Winter is when blizzards arive and blizzards can cut off power for a longish time, especially in the countryside. Seems that that could be a risk when you are away? We had a once in 20 year blizzard in the South Island last winter and that happened. Since our holiday season is in our summer, most houses were occupied, in fact nobody was going anywhere, so not too many burst pipes, although those houses with electrical heating only were getting rather cold at the end, especially as insulation is pretty poor in many of our houses.

jlaw · 01-07-13, 08:38 PM

In my area the sewer bill is tied to water usage as well. The wasted water of the 3/4" pipe will also reduce your sewer bill if that is the case for you. If you are using a water softener the reduced usage of salt would be a consideration.

12-04-12, 07:45 PM	#11
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	No, I haven't noticed any hydraulic noise. I'll listen more carefully for it next time I use the shower. I'm not sure if there is a water hammer suppressor installed on that water line. My guess would be no. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-10-12, 06:56 AM	#13
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I'd estimate roughly 20-25 feet of copper. Unfortunately, none of it is in reasonable lengths since I had to cut it up into smaller lengths just to remove it. Most of it is cut up and laying in a scrap pile I have. There is still ~9 feet in the wall that I couldn't get out because it was anchored to the studs and I didn't want to open the wall up. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

12-30-12, 01:38 PM	#14
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Just following up on this. I haven't noticed any hydraulic noise even when listening for it. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

01-07-13, 07:08 PM	#18
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Well, we never leave the houses totally unheated. We just turn down the temperature when we're away. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by Daox; 01-07-13 at 07:37 PM..

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

12-10-12, 05:52 AM	#12
Exalta-STA Apprentice EcoRenovator Join Date: May 2012 Location: Philippines Posts: 107 Thanks: 12 Thanked 4 Times in 4 Posts	Just curious, how many feet of copper piping did you remove and where is it now?

12-31-12, 10:46 AM	#15
FortyTwo The answer is renovation Join Date: Dec 2009 Posts: 3 Thanks: 25 Thanked 0 Times in 0 Posts	I replaced most of my basement plumbing and first floor runs with Pex (from copper). It made a significant difference in the kitchen, especially for the dishwasher. I had a high efficiency / low water consumption bosch dishwasher and it never drew enough water from the water line to get actual hot water. Now I run the kitchen faucet a bit to rinse dishes, and get the line hot before starting it. Also- I think that water hammer is greatly diminished with Pex- as it has some flex and give that rigid copper doesn't. I am so happy with Pex- I'm thinking of redoing it all again in a few months as a home run system, with all the shut offs and lines in one place in the basement. It is ridiculously fast and pretty cheap to use, and I have_never_had_a_leak.

01-07-13, 04:57 PM	#16
Snail Lurking Renovator Join Date: Jul 2011 Location: Palmerston North Posts: 20 Thanks: 3 Thanked 9 Times in 7 Posts	I've just replumbed my new-old house with small-diameter plastic piping. Longest pipe run from the central in-line condensing gas water heater is about 12 metres (40 feet). I just completed the wiring to the heater a day or so ago. The hot water comes through faster than the much shorter 3/4 inch copper pipe runs at my existing house and there is no propblem with pressure loss in this mains-pressure system. I ran some calculations on insulation. Given that you are going to loose all the heat in the pipe fairly quickly, regardless any insulation and given that even in a windly crawl space and with a 10 meter run of copper pipe the rate of heat loss from the hot water in the pipe to the air is at least an order of magnitude lower than the 10 to 30 kilowatts being supplied by your heater or cylinder whilst the tap is being run, complete pipe insulation is a waste of time and money in my climate. If you had a freezing blizzard passing the pipe and you were using the tap at the end of a long run at frequent intervals it just might be worthwhile I guess. So do the calculations first! If you have a hot-water storage cylinder, heat will be conducted from the cylinder along the pipe at all times, not just when water is flowing, So in this case, you need to insulate the pipe from the cylinder for a meter or two, so that the loss from this cause is low compared to the general losses through the cylinder lagging. Peter

01-07-13, 05:42 PM	#17
Snail Lurking Renovator Join Date: Jul 2011 Location: Palmerston North Posts: 20 Thanks: 3 Thanked 9 Times in 7 Posts	Having now reread the post on insulation, I'm properly embarrassed. Of course you need to insulate pipes where they might freeze, hot or cold, plastic or copper. My excuse is I'm now in a climate where that isn't an issue, unless the pipes are completely exposed, hence I misread the earlier post. (Also I've just come back from field work in Indonesia to an exceptionally hot summer Christmas at home. Freezing was a distant memory to me!) However, I'm curious now. I used to have a house where we did get freezing temperature, but usually only overnight and never for more than a day or so. What happens to those of you who live in climates where freezing temperatutes last for days, or even months? Surely, in that case, no practical amount of insulation will stop eventual freeze-up? If you are lucky enough to go for a winter holiday, what happens when the taps are not used for a significant period? Even pipes which are within the conditioned envelope must be at risk if the house is unheated. Ouch!

01-07-13, 08:05 PM	#19
Snail Lurking Renovator Join Date: Jul 2011 Location: Palmerston North Posts: 20 Thanks: 3 Thanked 9 Times in 7 Posts	Winter is when blizzards arive and blizzards can cut off power for a longish time, especially in the countryside. Seems that that could be a risk when you are away? We had a once in 20 year blizzard in the South Island last winter and that happened. Since our holiday season is in our summer, most houses were occupied, in fact nobody was going anywhere, so not too many burst pipes, although those houses with electrical heating only were getting rather cold at the end, especially as insulation is pretty poor in many of our houses.

01-07-13, 08:38 PM	#20
jlaw Learning to save Join Date: Dec 2012 Location: Eastern North Carolina Posts: 19 Thanks: 1 Thanked 3 Times in 3 Posts	In my area the sewer bill is tied to water usage as well. The wasted water of the 3/4" pipe will also reduce your sewer bill if that is the case for you. If you are using a water softener the reduced usage of salt would be a consideration.