Think of all the things that have an automatic and a manual version: Cars can be either stick shift or automatic transmission. Electric and hand juice squeezers. Compact discs and vinyl records. Microwaves and stove ovens. It can be debated one is clearly better than the other, but then again, if the newer automatic version is far superior, wouldn’t that make the old manual version obsolete? Even in the advent of the invention of the circuit setter balance valve, the manual balance valve still has its place in the in the HVAC and plumbing industry. There are noted advantages and disadvantages of both and depending on the hydronic system, the manual can be the more appropriate choice.
Manual Balance Valve
Manual balance valves have a combination of a ball valve and a venturi balancing device. They also have adjustable stems for valve port opening and used as a flow shut off point.
Pros:
- Suitable for residential homes and small buildings
- Has low turbulence from the venturi device which provides accurate flow readings
- Can read flow as low as .01 GPM
- Has a higher flow range than fixed circuit setters
- Best used on the return side of the hydronic system
- Saves energy with the a lower pressure drop and a smaller pump can be used
Cons:
- Valves must be manually calibrated
- They require constant costly maintenance
Circuit Setter
Circuit setters are calibrated balancing valves with a built in slide rule. They have predetermined Cv (flow coefficient) values that automatically regulates the flow of water through the terminals.
Pros:
- Suitable for large buildings
- Easy maintenance
- Work on a minimum level of horsepower
- Low setup and initial balance time
- Able to shut down water flow for individual parts of a building but keep water circulating in the rest of the building
Cons:
- High energy usage
- Has limited flow range
- Inaccurate flow readings due to high turbulence at measuring point
