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Verify that system is purged of air and filled to
proper pressure.
Verify proper pump operation per manufacturers
specifications.
Verify proper supply water temperature is available
and is at design temperature.
Proper air filter maintenance has been completed.
Fan belts are in proper working order.
Heat transfer devices (coils) are clean.
Strainers are clean.
All manual shutoff valves are open.
All bypass valves are closed.
No automatic or manual balancing valves exist
(if they do, they must be set fully open; not to interfere
with the pressure independency of the PICV)
Verify that each PICV valve has at least 2.3 psi, but less
than 60 psi dP across the valve to ensure they are in the
operating in the pressure independent range.
Less Effort with PICVs
Pressure dependent valves require more
commissioning time:
1. It is common to do three passes for proper balance
when using conventional control valves.
2. A change to a valve in a branch results in changes
to the flow through the rest of your system.
Required system balancing is labor intensive
Why pressure dependent valves require more commissioning time:
Typically, a balancer would start with the first valve and control loop on the right. They will set the manual balancing valve
so that the coil will get the flow it needs for design. Then the balancer moves on to the next one and sets it and so on, all
throughout the system on all of the valves. Every time the balancer sets another balancing valve, it affects the previous ones
that were already set. So traditionally they will repeat the process two or three times to reset those valves, which is very
time-consuming and labor-intensive. When the balancer is done, the system is balanced to the design parameters, but a
system rarely operates at design conditions. Therefore, the system is rarely balanced properly.
How PICV help in system balance and saving commissioning time:
Siemens PICVs make it easier to achieve system balance through use of the maximum flow setting feature and automatic
pressure regulator. The Siemens PICV allows the user to set the maximum flow for a given circuit, thus eliminating overflow
at the coil at design conditions. During operation, the automatic pressure regulator mitigates any flow variations due to
pressure changes and allows the PICV to deliver design flow rates to the coil. Both features help the balancer achieve
system balance efficiently allowing for the building to be commissioned quicker.
Impacts to Testing, Balancing, and Commissioning
When testing, balancing and commissioning systems with PICVs,
note that the two steps below MUST be done before beginning
flow verification.
Below are generally accepted methods for verifying flow when commissioning systems
Method #1 (System) – Total system flow verification for cooling/heating valves
Method #2 (Terminal) – Integrated PICV PT port verification for cooling/heating valves (operating range verification)
Method #3 (Terminal) – Air delta-T verification for cooling/heating valves
Method #4 (Terminal) – Water delta-T verification for cooling/heating valves
Method #5 (Terminal) – Coil ∆P verification for cooling/heating valves
Items to check before beginning flow verification procedure: