ta balancing methods

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Balancing methods TA Hydronic College Training

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HVAC hydronic system balancing methods

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  • Balancing methods

    TA Hydronic College Training

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    What is the purpose of balancing ?

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    Adjusting the design flows in all terminal units in design conditions (when all control valves are fully open), while creating minimum additional pressure drops.

    1) Call Santa Claus! 2) Have a method.

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    Infinity of possible balancing solutions

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    100 100 100 100 100

    0.5 psi 1 psi 2 psi 3 psi 4 psi

    3 psi 2 psi

    1 psi 1 psi 1 psi 0.5 psi 0.5 psi

    100 100 100 100 100

    100 100 100 100 100

    2.5 psi

    9.5 psi

    = 7.5 psi = 17.3 ft

    = 9.5 psi = 21.9 ft

    = 16.5 psi = 38 ft

    1.

    2.

    3. ...

    3 psi 2 psi 3 psi

    3 psi 4 psi 5 psi 6 psi

    10 psi 11 psi 12 psi 13 psi

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    Building brick: the hydronic module

    4

    Main balancing valve

    1 balancing valve per circuit

    Direct return piping 1 2

    3

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    Splitting into modules

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    Splitting into modules

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    Simplifying the drawing is essential

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    Splitting into modules

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    =Solution for the main module

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    Splitting into modules

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    =Another solution for the main module

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    Turning direction criteria for splitting into modules

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    At any bifurcation between many and many units turn in the direction of the main flow

    At any bifurcation between one and many units turn in the direction of the many units regardless of the flow

    30 gpm 30 gpm 4 gpm 4 gpm 4 gpm 30 gpm 4 gpm 4 gpm 4 gpm

    Remark: bifurcations can be or

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    Splitting into modules

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    =Find out the sub-modules (1)

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    Splitting into modules

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    =Find out the sub-modules (2)

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    Splitting into modules

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    = Find out the sub-modules (3)

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    Splitting into modules

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    A

    A.5

    A.4

    A.6

    =

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    Where to install balancing valves ?

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    Where would you install balancing valves ?

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    Exercise: Split the plant into modules and place valves

    =

    All black numbers is q in gpm All red numbers is p in psi

    Mark with where STAD/F is needed, use the smallest amount! Size all STAD/F regardless of pipe p

    6/2

    4/2 3/2 1/1

    1/1

    2/2 4/2 5/2

    7/3

    7/3

    5/2

    10/4 10/4

    8/3 8/3 1/1

    2/2

    12/4 1/1 4/2 4/2

    2/2

    2/2 2/2

    2/2 2/2

    2/2

    2/2

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    Exercise: Split the plant into modules, place and calculate valves

    =

    All black numbers is q in gpm All red numbers is p in psi All blue numbers in feet All circuit length is 10 feet

    Mark with where STAD/F is needed, use the smallest amount! Size all pipes and STAD/F in TA Select Compare the valve size from the previous exercise

    60 60 60 100

    30

    60

    60

    60

    150 150 60 60

    150

    60

    60

    60

    30 90

    30 60 60

    90 60 60

    60

    60

    5

    100

    6/2

    4/2 3/2 1/1

    1/1

    2/2 4/2 5/2

    7/3

    7/3

    5/2

    10/4 10/4

    8/3 8/3 1/1

    2/2

    12/4 1/1 4/2 4/2

    2/2

    2/2 2/2

    2/2 2/2

    2/2

    2/2

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    Balancing a module

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    The iterative method (trial and error) quickly becomes a nightmare because of hydraulic interactivity

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    Balancing a module

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    Exploit the proportion

    rule

    100

    30 20 10 20 20

    150

    45 30 15 30 30

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    Balancing a module

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    The proportion rule applies itself downstream

    from a perturbation

    10 10 10 10 10

    11 12 0 13 13

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    Balancing methods

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    Proportional method adapted from air system balancing methodologies not optimal in pressure drops

    Compensated method (Pr. Robert Petitjean) designed for application with balancing valves optimal in pressure drops

    TA Balance method (Pr. Robert Petitjean)

    fully computerized: automatic determination of the index valve optimal in pressure drops

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    The compensated method

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    54321

    Reference valve

    Preset the reference valve for a pressure drop of at least 1 ft at design flow. (use calculation disk or TA SCOPE)

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    The compensated method

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    100%

    Partner valve

    Obtain the design flow in the reference valve by adjusting the partner valve.

    Reference valve

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    The compensated method

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    100%

    Reference valve Partner

    valve

    Maintain the flow in the reference valve, by adjusting the Partner valve, while adjusting valve no 4. (by using the computer method in TA SCOPE on no 4)

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    The compensated method

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    54321

    100%

    100%

    Continue the procedure with valve no 3. The flow is maintained in the reference valve and in valve no 4 by virtue of the proportion rule. Continue until all valves is balanced in this module.

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    The compensated method

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    Reliable Each valve is adjusted only once Minimum pressure drops

    3 people needed 2 instruments needed Difficult if the index

    is not the reference

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    Order for balancing modules

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    A

    A.5

    A.4

    A.6

    =The structure of hydronic modules can be seen as a hierarchical tree. By virtue of the proportion rule, before a valve can be adjusted, all its children valves must themselves be adjusted. Before a module can be balanced, the whole descent of this module must be balanced.

    1 3

    2

    4

    Balancing order:

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    Order for balancing modules

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    Correct

    Correct

    Incorrect !

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    Setting of balancing valves by step 1

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 2

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 3

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 4

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 5

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 6

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 7

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    Fully open

    50% open

    Balanced

    Module @ work

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    Setting of balancing valves by step 8

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    Fully open

    50% open

    Balanced

    Module @ work

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    TA Balance method

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    TA Balance is a computerized balancing method incorporated in the TA SCOPE:

    1. Two measurements are performed on each valve

    2. It calculates the best settings for the balancing valves of the module

    Preliminary operations: Partner valve is fully open Balancing valves of all circuits are set at 50% opening

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    TA Balance method

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    54321

    For each valve : 1) Enter the design flow 2) Enter valve and setting 3) Measure the current flow 4) Shut the valve 5) Measure the pressure drop 6) Re-open the valve Repeat on all module valves For the partner valve : 1) Shut the valve 2) Measure the differential pressure 3) Re-open the valve

    TA SCOPE calculates and displays the required valve openings.

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    TA Balance method

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    The settings displayed by the TA SCOPE are adopted: Circuits of the module are then proportionally balanced. With the lowest pressure drops in the valves. (starting

    with selected min p in the index valve)

    Setting the partner valve to the design flow, now or in a later stage Gives the correct flows in every balancing valves of the module.

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    TA Balance method

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    Reliable Minimum pressure drops

    Only one person needed Only one instrumet needed The index valve is

    automatically detected Overall gain of 25% on

    the balancing time

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    Balancing methods

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    Proportional method adapted from air system balancing methodologies not optimal in pressure drops minimum 2 to 3 access to each valve 1 man; 1 instrument

    Compensated method (Pr. Robert Petitjean)

    designed for application with balancing valves optimal in pressure drops only 1 access to each valve (if index valve at the end) 3(2) men; 2 instruments needed

    TA Balance method (Pr. Robert Petitjean)

    fully computerized: automatic determination of the index valve optimal in pressure drops 1 man; 1 instrument 3 to 4 access to each valve

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    Balancing reveals the optimal set-point

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    Minimum pressure drops in the balancing valves

    All the pump head in excess is located in the main valve

    Re-open the main valve and adjust the pump speed

    1

    2

    3

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    Pump optimization

    All above 1 ft (0.5 psi) in p in the index valve and main valve is energy waste.

    .no balancing is completed before the pump is optimized

    50 gpm

    250 gpm

    40 psi

    14 psi 10.5 psi

    50 gpm 50 gpm 50 gpm 50 gpm

    13 psi 12 psi 11 psi 0.5 psi

    40 psi

    10.5 psi 4 psi 1 psi 2 psi 3 psi 0.5 psi

    30 psi

    0.5 psi 3 psi 2 psi 4 psi 1 psi 0.5 psi

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    Savings are real

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    Pfizer pharmaceutical production unit nearby Tours (France)

    Installed cooling capacity of 184,256 MBTUH (3 chillers in cascade) Total design flow: 3400 GPM Problem: production alarms! 80 TA balancing valves from STAD to STAF 8 Audit of plant with TA Select based on a first measurement campaign Presettings calculated with TA Select Viscosity corrections checked with TA Select Full balancing performed using TA-Balance on one TA-CBI

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    Savings are real

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    Industrial plant 184,256 MBTUH cooling capacity 3900 GPM 49 psi pump head

    After balancing

    3400 GPM (-13%)

    No production alarms!

    Before balancing

    39 psi pump head (-20%)

    Pumping power reduction : 52 HP

    Savings : 17200 /year 24000 $/year

    Balancing methodsWhat is the purpose of balancing ?Infinity of possible balancing solutionsBuilding brick: the hydronic moduleSplitting into modulesSplitting into modulesSplitting into modulesSplitting into modulesTurning direction criteria for splitting into modulesSplitting into modulesSplitting into modulesSplitting into modulesSplitting into modulesWhere to install balancing valves ?Exercise: Split the plant into modules and place valvesExercise: Split the plant into modules, place and calculate valvesBalancing a moduleBalancing a moduleBalancing a moduleBalancing methodsThe compensated methodThe compensated methodThe compensated methodThe compensated methodThe compensated methodOrder for balancing modulesOrder for balancing modulesSetting of balancing valves by step 1Setting of balancing valves by step 2Setting of balancing valves by step 3Setting of balancing valves by step 4Setting of balancing valves by step 5Setting of balancing valves by step 6Setting of balancing valves by step 7Setting of balancing valves by step 8TA Balance methodTA Balance methodTA Balance methodTA Balance methodBalancing methodsBalancing reveals the optimal set-pointPump optimizationSavings are realSavings are real