Here, I’m going to sum up a more elaborated article on the subject which was originally written in Persian language and is available at:
Basically, selecting an approach for balancing a large-scale hydronic HVAC system depends on various parameters, e.g.
- system size,
- complexity,
- variable/constant flow system
- required level of balancing
- required level of control
- the budget
I believe that, all in all, the following table sums up the methods available to balance a HVAC hydronic system, having control aspects in mind. For each and every approach, merits and demerits are listed for you to be able to select the one that fits your own project:
| Pumping System | Cost | Control Quality | Balancing Quality | Energy Efficiency | Complexity of Installation and commissioning | Space Requirement | Other equipment required | |
| Manual Balancing Valve (DRV) | Constant Flow | Low | – | Med | Low | Low | Low | – |
| 3-Way Motorized Valve | Constant Flow | Med | Med | – | Low | Med | Med | Controller, Temp Sensor, Switchbox |
| Constant Flow Regulator (CFR) | Constant Flow | Med | – | High | Low | Low | Low | – |
| Combination of 3-Way and DRV | Constant Flow | High | Med | Med | Med | High | High | Controller, Temp Sensor, Switchbox |
| Combination of 2-Way and Differential Pressure Control Valve (DPCV) | Variable Flow | High | High | High | High | High | High | Controller, Temp Sensor, Switchbox, Single pressure test point on supply line |
| Pressure Independent Balancing and Control Valve (PIBCV) | Variable Flow | High | Very High | Very High | Very High | Low | Low | Controller, Temp Sensor, Switchbox, Differential pressure transmitter, Pump Drive, one CFR of minimal size for each main branch/floor/building |