High Rise Piping Design
High Rise Piping Design
(OP)
Currently working on a renovation to a 40-story building which has a low and high zones for the HVAC hydronic piping. The client rep would like to install a single zone. Does anyone have experience with this type of zoning? We prefer to maintain the existing zoning.





RE: High Rise Piping Design
Without knowing to much about your system I would say that a single zone serving an entire floor is going to leave the occupants unhappy, regardless of what the owner says.
RE: High Rise Piping Design
sorry for the lack of information. The "low zone" serves floors 2 to 21 and the "high zone" serves floors 22 to 41. The existing system is a reverse return.
RE: High Rise Piping Design
RE: High Rise Piping Design
With high rise buildings and lots of tap-offs, branches, FCUs, etc., balancing is a nightmare.
HVAC68
RE: High Rise Piping Design
RE: High Rise Piping Design
Fortunately there aren't too many high rise building in the UK, so we don't have a lot of experience on this. The highest I have worked on is about 14 storeys.
High quality radiators will work at about 7 bar (70m head approx) so this I guess would equate to 14 stories. So I assume you would (based on this principle) have main plant rooms at 14 storey intervals. (i.e. zones up to 14 stories).
If fan coil units are proposed, then these can work at higher pressures (i.e. 10Bar or more) , but the fittings also have to be equivalantly rated or leaks will occur.
I would guess you have a lot of heat exchanger units at the 'zone' plant rooms with major plant either on the roof or in the basement (depending on what it is. I suppose rooftop plant is preferred for getting exhausts away and ejecting heat from towers and so on.
I have seen some projects use PRV pressure reducing valves and safety valves (to take out the excess pressures)but I don't like that idea.( too much unreliability and maintenance)
Is there anyone out there who has designed a really high building...if so, what did you do??
I am really interested.
Friar Tuck of Sherwood
RE: High Rise Piping Design
For example, taking SAK9 4.5 m floor to floor
If the chiller is at a low floor, the evaporator, pumps and lower floor equipment would need to be rated at 4.5m x 40 = 180m static hd + margin.
If the chiller was located at the roof level, the AHU coils/FCU coils, etc. for the lowest floors would suffer 180m static hd. + margin.
I design high rise buildings in Hong Kong, and split the vertical zones to avoid excess static head. That saves buying "specials" chillers, pumps and equipment, which also tend to have much longer delivery periods - that how it is done.