# Recirc piping high rise



## Ptturner91 (Oct 13, 2012)

Hey guys ! Most of my experience is low rise commercial and low rise res 

My question is in a high rise building like a condo lets say I've noticed that there is usually one big pump for the recirc line that does each zone (top half of building and one for the lower half of the building) how is it tied in to each riser? Sorry if this sounds like a dumb question I'm just not as experienced in this area as some of you may be 

Thanks again


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## wyrickmech (Mar 16, 2013)

Ptturner91 said:


> Hey guys ! Most of my experience is low rise commercial and low rise res My question is in a high rise building like a condo lets say I've noticed that there is usually one big pump for the recirc line that does each zone (top half of building and one for the lower half of the building) how is it tied in to each riser? Sorry if this sounds like a dumb question I'm just not as experienced in this area as some of you may be Thanks again


it will be tied into the end of the hot. This would be the farthest point away from the main risers. How we do it is the placement of two ball valves a flow control device and a check valve.


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## Ptturner91 (Oct 13, 2012)

wyrickmech said:


> it will be tied into the end of the hot. This would be the farthest point away from the main risers. How we do it is the placement of two ball valves a flow control device and a check valve.


Yeah but these ones have recirc mains so I'm told that re connect to each riser? I don't quite understand


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## wyrickmech (Mar 16, 2013)

Ptturner91 said:


> Yeah but these ones have recirc mains so I'm told that re connect to each riser? I don't quite understand


is there a pump on every floor?


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## Ptturner91 (Oct 13, 2012)

wyrickmech said:


> is there a pump on every floor?


No there isn't one big pump on the top and does floors 8-16 and there are 6 suites on every floor! How would that be piped?


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## wyrickmech (Mar 16, 2013)

Ptturner91 said:


> No there isn't one big pump on the top and does floors 8-16 and there are 6 suites on every floor! How would that be piped?


every level would go back to a recirculating riser then the riser would feed the pump. Pump would feed the storage tank then back in the hot water riser


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## Ptturner91 (Oct 13, 2012)

wyrickmech said:


> every level would go back to a recirculating riser then the riser would feed the pump. Pump would feed the storage tank then back in the hot water riser


Ok ! Kinda makes sense I guess I'll have to wait till I get called out there again and try and see it


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## wyrickmech (Mar 16, 2013)

Ptturner91 said:


> Ok ! Kinda makes sense I guess I'll have to wait till I get called out there again and try and see it


any time


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## leakfree (Apr 3, 2011)

We've done quite a few 5 and 6 story buildings with no true return risers.We collect all the hot risers in the ceiling below the top floor with a check/valves/circuit setter on each branch and take them down in one return line to the circ. pump.The hot water just circulates thru the hot risers and down the one return line,they're drawn that way by the mechanical engineers and it seems to work well.


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## wyrickmech (Mar 16, 2013)

leakfree said:


> We've done quite a few 5 and 6 story buildings with no true return risers.We collect all the hot risers in the ceiling below the top floor with a check/valves/circuit setter on each branch and take them down in one return line to the circ. pump.The hot water just circulates thru the hot risers and down the one return line,they're drawn that way by the mechanical engineers and it seems to work well.


on a multi story building that would not be economical. Why take the recirculating loop all the way to the top floor? The return riser would be the one line going back to the pump.


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## leakfree (Apr 3, 2011)

wyrickmech said:


> on a multi story building that would not be economical. Why take the recirculating loop all the way to the top floor? The return riser would be the one line going back to the pump.


Example:6 story building with 20 units per floor,each one has a kitchen,bath,laundry all on different wet walls, thats 60 sets of risers with a cold,hot,return line going all the way up.Now take that return loop that you'll have to put in either way and move it from the ground floor to the 5th and I can eliminate all 60 of those recirc lines(@10' per floor x60 risers x4 floors I just put 2400 ' of pipe in my pocket,plus 240 cores)and bring just ONE down from the 5th floor as I actually use the hot riser to finish the recirc loop.That one recirc line coming down from the 5th will be a larger line,but I'll guarantee you it will cost less in material ,cores,and labor than the 60 lines you'll run.


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## wyrickmech (Mar 16, 2013)

leakfree said:


> Example:6 story building with 20 units per floor,each one has a kitchen,bath,laundry all on different wet walls, thats 60 sets of risers with a cold,hot,return line going all the way up.Now take that return loop that you'll have to put in either way and move it from the ground floor to the 5th and I can eliminate all 60 of those recirc lines(@10' per floor x60 risers x4 floors I just put 2400 ' of pipe in my pocket,plus 240 cores)and bring just ONE down from the 5th floor as I actually use the hot riser to finish the recirc loop.That one recirc line coming down from the 5th will be a larger line,but I'll guarantee you it will cost less in material ,cores,and labor than the 60 lines you'll run.


so you make a riser per unit? That isn't the way we do a multi floor building here. One set of risers from the bottom to the top loops on every floor that just cut your footage down more.


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## tylerbee (Feb 14, 2014)

Ptturner91 said:


> Hey guys ! Most of my experience is low rise commercial and low rise res
> 
> My question is in a high rise building like a condo lets say I've noticed that there is usually one big pump for the recirc line that does each zone (top half of building and one for the lower half of the building) how is it tied in to each riser? Sorry if this sounds like a dumb question I'm just not as experienced in this area as some of you may be
> 
> Thanks again


I did quite a few recirc lines in 4 story buildings... There is a 1/2" pex line run to the top floor then tied into the hot riser just below the copper header with a 3/4" x 1/2" tee.. this is run to each top floor unit in the building.. the lines connect to a 3/4" reverse return line in the crawl space.. this 3/4" supply and return are run into the mech room.. return is connected to a recirc pump going to hw tank... all this is done in the early construction stages...


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