4 story apartment, new tubing for hot water rads?

GW

Hello, I have a 4 story heating job we are about to start, new panel rads with new boilers. I am a little concerned about expansion and contraction noises, we will have risers that feed the upper 3 stories and the people on the 1st 3 floor may hear the piping in the boxed out riser runs. We will have 4 risers to feed the 6 radiators per floor.



I wondered if anyone here has ran this much vertical length; we do two story houses all the time and a 3 story on occasion. I will even get some soft L if need be. I am not sure if Fosta pex will be adequate, these are not constant circ jobs, just on-off stats. there will be an outdoor sensor, but that means nothing if a heat call comes on when it's super cold out.



Thanks for any input,



Gary Wilson

GW

ACR?

ACR seems to be the same wall thickness as L, has anyone used acr for heat runs?

Jean-David Beyer

these are not constant circ jobs

Could you run them as (nearly) constant circulation jobs?



My house is two stories with the boiler in the attached garage, so my maximum height is only 5 feet or perhaps less. My thermostats are straight on-off ones (Honeywell digital ones). But I do get some expansion noise from upstairs. I have diddled the outdoor reset for the upstairs to be extremely close to the actual heat loss, so that zone can run 18 hours straight sometimes. I have 2F setback there at night, so I can detect expansion noise when it comes out of it, but not during the day. Before I had outdoor reset, it expanded and contracted all the time and was very annoying.

Unknown

making sense

finally

Charlie from wmass

Acr is just capped and cleaned pipe.

The expansion rate is the same. The use of expansion compensators would help. You may want to offset at every other floor to give an expansion joint. You need to support it to the structure at each floor so you can not have it expand and lift the 2nd, 3rd, and 4th floor supports and transfer the weight to the first floor riser clamp or hanger.

GW

which is softer?

It's been years since I snaked soft L, since the advent of pex. This is not a budget job, I am happy to spend the extra cash on copper just to keep all the tenants happy. Is ACR and L the same in regard to softness? 

GW

yes

I considered doing vitodens 200s with room sensors but thought there's still going to be a nighttime set back and there would be nothing to prevent tenants from jacking their settings in the morning causing the same affect as an on-off boiler.



Actually if we cant get a venting drawing from Viessmann we're going with another brand, but that's another thread for another day. One challenge at a time. The building owners handed me the car keys and they trust that I'll do a good job; they don't care how i do it!

David Sutton_6

3 storys and 6 apts

I did this with BB all the runs were fosta pex. with the coating on it , it slides real smooth and not a sound still 5 yrs latter.

GW

nice

The 3rd floor piping went straight from the basement to the to top story? I may be in good shape since it's just a bunch of one zone systems with no dhw. Would you try the fourth floor with fosta?

David Sutton_6

Yes and yes

each apt had its own zone with its own circ,one thing i did do was to bump up the presure in the expantion tank to 15#'s and set the auto feed to the same, its been fine and all apts nice and warm. and yes i would go to the 4th floor if needed.