PRESENTS

RICHARD A. WING

General Manager

ITI Certified TABB Technician

A Balancers Perspective on

PICCV Valves

Go with the Flow

Common Hydronic Formulas1 GPM = P X CV ( SEE NOTE )

2 BTU = CFM X 1.08 X T AIR

3 BTU = GPM X 500 T WATER

4 GPM = BTU

500 X T WATER

5 T WATER = BTU / GPM

500

6 T AIR = GPM X 500 T WATER OR BTU

CFM X 1.08 CFM X 1.08

7 GPM = FPS X (ID2 X 2.45)

8 FPS = GPM

ID2 X 2.45

(NOTE) CV = FLOW COEFFICIENT THAT WILL PASS A QUANTITY OF

60 DEGREE WATER THROUGH AN OPEN VALVE @ 1 PSI P

EXAMPLE:

CV 10 , P = 9 PSI

P X CV

9 X 10

3 X 10 = 30 GPM

Direct Return Piping

200% of terminal flow

100% of total flow

40% of terminal flow

THE FIRST ELEMENT SUPPLIED IS THE FIRST ELEMENT RETURNED.

Since the highest p is at the first element, the first element gets the lions share.

A time consuming balancing effort is required to test adjust and balance.

Reverse Return Piping3 Pipe System

100% of total flow

100% of circuit

100% of circuit

100% of circuit

THE FIRST ELEMENT SUPPLIED IS THE LAST ELEMENT RETURNED.

Since the p is equal at all the elements, the flow is also equal.

Little time is required to test adjust and balance

Flow vs. BTU Output

FLOW GPM BTU T EWT LWT

100% 30 300000 20 200 180

50% 15 270000 36 200 164

T = 20 F

Full FlowNo Balancing Valves / With Balancing Valves

50% Flowwith Balancing Valves / with PICCV

PICCV Pros/Cons

ADVANTAGES

1. FLOW STABILITY OVER A WIDE RANGE OF PRESSURES

2. LIMITS OVER PUMPING

3. OPENS AS P DROPS.

IT'S DYNAMIC

4. REDUCES INITIAL BALANCING TIME

5. ADD TO SYSTEM WITHOUT REBALANCING

6. ONE PIECE INSTALLATION RATHER THAN TWO PIECES: (ONE ATC VALVE AND ONE BALANCING VALVE)

DISADVANTAGES

1. NEED HIGHER TDH (MIN of 2.3')

2. NOT READILY ADJUSTED FOR FLOW INCREASE

(UNLESS CONTROLLER IS SET FOR 90%(ADJ) POSITION AT THE DESIGN GPM)

Perfect Application2 POSITION

PICCV

A PRIMARY LOOP CHILLED WATER SYSTEM WITH ONE "HEADER" TO SUPPLY MORE

THAN ONE COMPONENT. ALTHOUGH THE VFD (OR SEVERAL PUMPS IN PARALLEL)

WILL CHANGE THE TOTAL FLOW, THE INDIVIDUAL CHILLERS WILL VARY THEIR

CAPACITY AS SYSTEM P CHANGES.

VFD

RememberGo with the Flow.

Know where you are

Know the pressure