montgomerysj
Mechanical
- Apr 15, 2009
- 7
We have a two pipe direct return cooling pipe system for a campus of buildings. There are differing views as to whether the main balance valve for each building should be in the supply or return line.
1) One view is that it will be easier to set the flow into the building, if the balance valve is on the supply.
2) The other is that having the balance valve on the return will reduce air and noise in the system.
1997 ASHRAE Fundamentals Handbook, page 33.4 says -- Compared with placement on the supply side, balance valves on the return side will reduce the amount of free air in the coil.
From ashrae above it is obvious that each individual coil should have the balance valve on the return. Would this also hold true for the building as a whole?