Air Chambers for modern fixtures

[dhill]

Are air chambers still necessary for supply lines going to fixtures in new plumbing?

[Rich]

I would say - yes - at all fixtures.

[bkrahmer]

You've picqued my curiousity. Can you tell me what you guys are talking about?

[Rich]

Water hammer arrrestor
http://www.factsfacts.com/MyHomeRepair/WaterHammerArresters.htm

[giddonah]

I'm glad you asked bk, I was starting to think I was the only one who was googling every other thread.

[dhill]

LOL. You guys remind me too much of myself! Thanks for the response, Rich. Maybe you can help me with this. Since my plumbing line total is only about 12 feet, all in one wall, do you think it would be okay to put one hammer arrestor on each line (hot and cold) between the last two fixtures, instead of trying to use arrestors for each fixture? My plumbing line is very simple and because I'm not using any automated closure valves that shut down fast, I'm thinking one arrestor on each line should be okay. In fact, the reason I asked the question in the first place is because I figured modern fixtures should compensate for the hammering effect in some way. Thanks again.

[Rich]

Is what I would probably do is put in an expansion tank - there are several diaphragm type expansion tanks that aren't very large - you can install it on the cold water feed and it should handle most problems with water hammer.
Depending on pipe size and GPM , etc..etc.. will depend on the size of the hammer arrestor. And I should note - I say hammer arrestor - not air chamber. An air chamber is just an extension pipe going vertical 6-24" whereas a hammer arrestor is has an internal diaphragm that doesn't allow water or air to become rancid and there is now draining down the system every year to recharge the air chambers.

[dhill]

Thanks, Rich. Ya, I'd already determined air chambers were too iffy, and arrestors much better. So if I use an expansion tank, where is it placed? Are they small enough to fit inside a 6" wall? My water feed is from a well and pressurized water tank. I'm not sure how many gpm's I'll be running. My pressure tank is set for 50 psi. Line coming in is 3/4 poly, but I'm downsizing to 1/2 inside the house run. Since you're being so helpful :), I'll ask my next question directly here. What's best to run for my water lines, cpvc, pex or copper?

[giddonah]

I have a feeling that last question should have its own thread considering the conversation that might ensue.

[dhill]

Yeah, you may be right, but I figured I was here, so I blurted it out.

[Rich]

Most expansion tanks are around 12-16" around and about 20" tall - that's a rough estimate anyway. So it wouldn't fit in a wall. Anyway - the tank is usually placed on your supply line coming into the house before it branches to the water heater and the rest of the house.
Hmmm... take a look at your pressurized water tank. It might already have an air diaphragm in it.

:) I personally like copper but the pex is gaining popularity and is just as good if not better than the copper in the long run. Not sure if I would go with the cpvc - I'm sure it would still work though.

[dhill]

Thanks, Rich.

[bkrahmer]

I will be finishing the rest of my pex lines in a few days, but I did 4 the other night. Took 5 minutes to run about 100' of tubing for the 4 lines. I love the stuff.

[dhill]

Thanks, BK. I'm leaning towards pex.

[Rich]

The main reason for my liking copper is from a GC standpoint. The installation of copper looks so much cleaner than a pex install.. with copper you get straight runs and a 90.. with pex you get a winding run with wide looping corners. Appearance means a lot to some people (homeowners) :)