Transcript Hydronic Balancing

Hydronic Balancing
Using Automatic
Balancing Valves to
Dynamically Balance
Hydronic Systems
Sean Kalman – Hays Fluid Controls
Agenda
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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
Automatic Balancing Valves
Methods of Hydronic Balancing
Balancing Valve Type
Ball Valve
Circuit Setter
Venturi
Automatic
Information
Inexpensive & Inaccurate
Moderately Priced &
Somewhat Accurate
Higher Priced with Improved
Accuracy
First Cost eqivalent to Venturi,
Lower TAB Cost
Automatic Balancing Valves
How Automatic Flow Control Works
Flow
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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.
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When Differential Pressure
decreases, the diaphragm
relaxes, and increases the area
for the water to flow through.
Automatic Balancing Valves
Automatic Flow Control Valves
Save Money
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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
Automatic Balancing Valves
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 Balancing Valves
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
for your design.
Automatic Balancingflexibility
Valves
Automatic Is Accurate
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Most manual valves give somewhere between
±15% to ±25%
Automatic valves increase your accuracy to
±10% as a general rule
Automatic Balancing Valves
Lower Installation Cost
5 Components
1 Package
4 Connections
17 Components
21 Connections
Automatic Balancing Valves
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.
Automatic
Balancing
Valves
Less Valves Required With AFCV
No balancingAutomatic
valveBalancing
required
Valves 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.
.5 Hrs to verify flow on AFCV.
$50 / Hour Labor
X
1.5 Hrs
$75 Per Coil
X
100 Coils
$7500 Balancing Cost
$50 / Hour Labor
X
.5 Hrs
$25 Per Coil
X
100 Coils
$2500 Balancing Cost
Automatic Balancing Valves
Less Energy Consumed With AFCV
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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.
Automatic Balancing Valves
Less Energy Consumed With AFCV
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.
Automatic Balancing Valves
Less Energy Consumed With AFCV
Automatic Balancing Valves
Less Energy Consumed With AFCV
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%
Automatic Balancing Valves
AFCV With Variable Speed Pumps
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Automatic Can accommodate changes in
system.
Only AFCV can change to maintain exact flow
rate.
For use with 2 position valves is excellent
application.
Automatic Balancing Valves
AFCV With Variable Flow Systems
Many engineers have suggested that AFCV is not suited for variable
flow systems. Here are some reasons they are perfect for the job:
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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.
Automatic Balancing Valves
Cost Savings With AFCV
27 Circuit Setters = $729
Installation Labor = $675
TAB Labor = $2,025
Total Installed Cost = $3,429
18 AFCV = $954
Installation Labor = $450
TAB Labor = $450
Total Installed Cost = $1,854
In this example,
weBalancing
saved
$1575 first cost alone.
Automatic
Valves
Where to use Automatic Flow
Control Valves
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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 Balancing Valves
Automatic Flow Control Placement
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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 Balancing Valves
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.
Automatic Balancing Valves
AFCV For All Applications
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A small inline
valve will work
in tight spaces
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A multipurpose
valve provides
unlimited options.
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Larger valves
accommodate high
flow rates.
Automatic Balancing Valves
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 Balancing Valves
Automatic Flow Control Valves
Automatic Balancing Valves
Conclusion
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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.
Automatic Balancing Valves