Hydronic Balancing Using Automatic Balancing Valves to Dynamically Balance Hydronic Systems Sean...

Hydronic Balancing

Using Automatic Balancing Valves to Dynamically Balance Hydronic Systems

Sean Kalman – Hays Fluid Controls

Automatic Balancing Valves

Agenda

Methods of Hydronic Balancing How Automatic Flow Control Works Automatic Flow Control Saves Money Where to Apply Automatic Flow Control Valves Selecting an Automatic Flow Control Valve


Methods of Hydronic Balancing

Balancing Valve Type Information

Ball Valve Inexpensive & Inaccurate

Circuit Setter Moderately Priced & Somewhat Accurate

Venturi Higher Priced with Improved Accuracy

Automatic First Cost eqivalent to Venturi, Lower TAB Cost


How Automatic Flow Control Works

When the Differential Pressure increases, the diaphragm presses up to and flexes against the orifice plate. This limits the area for the water to flow through.

When Differential Pressure decreases, the diaphragm relaxes, and increases the area for the water to flow through.

Flow


Automatic Flow Control Valves Save Money

Less Valves Required in System Higher Accuracy Lower Installation Cost Lower Test, Adjust & Balance Cost Lower Long Term Maintenance Cost Lower Pumping Capacity Requirement Can Be used in Variable Flow Systems


Typical Manual Balancing System

•Circuit Balance Valves required at all terminal units as well as riser.

•System to be rebalanced when new terminal unit brought on line.


Automatic Flow Control System

•Automatic Flow Control Valves only required at terminal units.

•No system rebalance needed when new terminal unit brought on line. AFCV dynamically adjust to maintain flow.

•No AFCV required on riser.

AFCV offers unmatched flexibility for your design.


Automatic Is Accurate

Most manual valves give somewhere between ±15% to ±25%

Automatic valves increase your accuracy to ±10% as a general rule


Lower Installation Cost

17 Components21 Connections

5 Components1 Package4 Connections


Less Valves Required with AFCV

In this manual system, 26 manually adjusted flow control valves are required. In the same system using automatic valves, only 18 valves are required.


Less Valves Required With AFCV

No balancing valve required in bypass with AFCV


Lower TAB Cost

Because AFCV are pressure independent, they are balanced from the time the pump is turned on. Thus, only flow verification is needed, saving as much as 60% over outdated manually adjusted valves.

1.5 Hrs to manually balance 1 coil.

$50 / Hour LaborX1.5 Hrs$75 Per CoilX100 Coils$7500 Balancing Cost

.5 Hrs to verify flow on AFCV.

$50 / Hour LaborX.5 Hrs$25 Per CoilX100 Coils$2500 Balancing Cost


Less Energy Consumed With AFCV

When your building load changes, AFCV can dynamically change to maintain your flow requirements.

When the ΔP decreases, the valves open to maintain a constant flow rate.

When the ΔP increases, the valves close slightly to maintain a constant flow rate.

Manually adjusted valves cannot adjust to the changing ΔP to maintain a constant flow rate. If ΔP increases, so does the flow, if ΔP decreases, so does the flow.



Application:

In an office building on a Spring day, the building may not be calling for less chilled water than what it was designed for. Except for a cafeteria which is at 100% capacity. By using AFCV, you can reduce your pump speed to meet only the chilled water need you have. With manually adjusted valves you do not have that luxury. In turn, reducing your pumping cost and saving money.



How Flow balancing cuts HVAC energy costs. (Use .06 kwh-hr cost) Flow Parameters Unbalanced Flow Balanced Flow

Flow, GPM 1050 870 Pressure, ft of head 62 75 Power, BHP 21.8 19.8 Power Consumptioin, KWH 18.2 16.4 Cost Per KWH $0.06 $0.06 Annual Electrical Cost $7098 $6396 Annual Savings $0 $702 Annual Savings Percent 0% 9.9%


AFCV With Variable Speed Pumps

Automatic Can accommodate changes in system.

Only AFCV can change to maintain exact flow rate.

For use with 2 position valves is excellent application.


AFCV With Variable Flow Systems

Control Valve has complete authority except when fully open and flow is beyond design.

Prevents “Overflow” of coil. Aids in preventing valve cavitation. Aids in preventing premature erosion of control

valve body.

Many engineers have suggested that AFCV is not suited for variable flow systems. Here are some reasons they are perfect for the job:


Cost Savings With AFCV

27 Circuit Setters = $729Installation Labor = $675

TAB Labor = $2,025Total Installed Cost = $3,429

18 AFCV = $954Installation Labor = $450

TAB Labor = $450Total Installed Cost = $1,854

In this example, we saved $1575 first cost alone.


Where to use Automatic Flow Control Valves

Water Source Heat Pumps Fan Coils VAV Box with Reheat Coils Air Handlers Unit Ventilators Cabinet Heaters Radiant Floor Heating Systems Hydronic Baseboard Heaters Cooling Towers Chillers


Automatic Flow Control Placement

In most applications, it is best to place the AFCV on the return side of a coil. This ensures that your water tube is full and providing maximum heat transfer.

Supply side will work, but is not ideal as too much air or turbulence may occur.


Automatic Flow Control Placement

In an open system, the AFCV must be on the return side of the coils to ensure that the tubes are flooded and ensure maximum heat transfer.

In an closed loop system, the AFCV can be on the return side or the supply side of the coils. The best practice is still to have your AFCV on the return side.


AFCV For All Applications

A small inline valve will work in tight spaces

A multipurpose valve provides unlimited options.

Larger valves accommodate high flow rates.


Choosing The Right AFCV

Choosing the right AFCV is very important. Here are some items to consider when choosing an AFCV:

•Operating Range:AFCV have a PSID range that they will operate within. Make sure the one you choose meets your needs.

•Flow Rates Available:Most AFCV manufacturers provide several flow rates to choose from. Some have a better selection than others. Make sure you are getting the flow rate you need.

•Hassle Free Operation:Ask the manufacturer if there are maintainance isssues with their valves. Will you have clogging problems or noise problems?


Automatic Flow Control Valves

SATISFIED

CUSTOMER

Inst

alla

tion

Valve Selection

No

Cal

lbac

ksComfort

Balance


Conclusion

AFCV are a good application in all types of systems.

AFCV saves money on both installation and operation of system

AFCV are best option for balancing of Hydronic HVAC systems.

Hydronic Balancing Using Automatic Balancing Valves to Dynamically Balance Hydronic Systems Sean...

Documents

Transcript of Hydronic Balancing Using Automatic Balancing Valves to Dynamically Balance Hydronic Systems Sean...