© Belimo University 2011, All Rights Reserved

© Belimo University 2011, All Rights Reserved
Enhancing Sustainability Advantages of pressure independent control valves; basic commissioning of Belimo PI valves. This presentation is an overview of Pressure Independent Valves and how they can eliminate waste by saving pumping energy as well as increasing chiller efficiency by reducing low delta T syndrome. © Belimo University , All Rights Reserved 1

Enhancing Sustainability
First, an analogy between air systems and hydronic systems. Why are there no more VAV pressure dependent air systems? I’d like to start our discussion today with a question. How many pressure dependent VVT terminal units have you specified or installed lately? Not too many? Why not? Let’s take a look at a typical pressure dependent VVT air system. As you can see, we’ve got a constant volume fan in the air handling unit, a number of pressure dependent terminal units, a balancing damper at each terminal unit, and a bypass (“dump”) damper to keep from over-pressurizing the system. The pressure-dependent terminal unit dampers are controlled directly by the space temperature sensors. Of course the key difference between a pressure-dependent and a pressure-independent terminal is that the pressure dependent damper is controlled strictly by the offset between actual room temperature and room temperature setpoint. Whereas with the pressure-independent terminal, the room temperature offset from setpoint is used to reset the actual terminal unit airflow from minimum value to maximum value. The air handling unit and terminal units are all sized and selected for design conditions, and the balancing dampers are set for design airflow as well. And at design conditions, this system works great. But how much of the time are we at design conditions? When we are not at design conditions pressure variations in the ductwork cause airflow to be inconsistent from terminal to terminal resulting in overflow and underflow conditions at the terminal level.

Pressure Dependent VVT System How many Pressure Dependent VVT systems have you seen lately? Air Handling Unit Return Duct VVT Boxes Supply Duct Bypass Space Temp Balancing Damper I’d like to start our discussion today with a question. How many pressure dependent VVT terminal units have you specified or installed lately? Not too many? Why not? Let’s take a look at a typical pressure dependent VVT air system. As you can see, we’ve got a constant volume fan in the air handling unit, a number of pressure dependent terminal units, a balancing damper at each terminal unit, and a bypass (“dump”) damper to keep from over-pressurizing the system. The pressure-dependent terminal unit dampers are controlled directly by the space temperature sensors. Of course the key difference between a pressure-dependent and a pressure-independent terminal is that the pressure dependent damper is controlled strictly by the offset between actual room temperature and room temperature setpoint. Whereas with the pressure-independent terminal, the room temperature offset from setpoint is used to reset the actual terminal unit airflow from minimum value to maximum value. The air handling unit and terminal units are all sized and selected for design conditions, and the balancing dampers are set for design airflow as well. And at design conditions, this system works great. But how much of the time are we at design conditions? When we are not at design conditions pressure variations in the ductwork cause airflow to be inconsistent from terminal to terminal resulting in overflow and underflow conditions at the terminal level.

Pressure Dependent VVT System Air Handling Unit Return Duct VVT Boxes Supply Duct Bypass Space Temp Balancing Damper Part Load Performance: Unable to respond to flow variation due to changing pressure conditions. Unstable control – system is “oversized”. Occupant comfort and energy efficiency are compromised. Spaces too cold (or hot). But at part load conditions (almost all the time), it doesn’t work so well. As the dampers in the terminal units close down, the pressure conditions in the ductwork change. The two things that determine the air flow through a damper are the damper position (% open) and the pressure differential across the damper. And because the pressure dependent terminal has no way to compensate for these changes in pressure, the terminals start to fight one another. Whenever the damper in Terminal 1 changes position, that changes the pressure conditions at all the other terminals. The dampers are having to react not only to changes in the cooling or heating load in the space, but also to the position of every other terminal damper! Second, the terminal that was perfectly sized for design conditions, and the balancing damper that was set perfectly for design airflow, now have far too much capacity for these part-load conditions. What formerly was a forgiving, stable condition permitting good control is now a knife edge - you’re continually over- and under-shooting. And because the terminals are now over-sized, the terminals closest to the fan consume far more air than required, starving the downstream boxes. Finally, as the dampers continue to close off, the dump damper opens up, returning air to the unit that is much colder (or hotter) than it should be. And that’s why you haven’t installed many pressure-dependent terminals lately.

Pressure Independent VAV Box Air Flow Temp. Control Controller Air Flow Measurement Device Water Flow Measurement Device Water Flow Controller From Temp. Control Part Load Performance: Flow is controlled under all pressure conditions. Pressure Independent Control Valve Pressure-independent terminals provides tremendous improvement in efficiency and occupant comfort at part-load conditions. The pressure independent terminal adds an airflow measurement device, and a controller with software to adjust the damper to provide just the airflow needed to satisfy the load. Now instead of controlling the damper directly, the space temperature sensor is resetting an airflow setpoint. No longer is the airflow through the terminal subject to the pressure conditions at the damper. No more fighting terminal dampers. Stable, consistent control with improved occupant comfort. Reduced fan energy. Pressure independent terminals are more expensive than pressure-dependent terminals, but their advantages are so universally recognized that this technology has come to dominate the industry. ADVANCE Pressure independent control valves operate much like pressure independent terminal units, except in a different medium (water instead of air). Previous generations of PI control valves accomplished this by mechanical means. These valves work very well, but it takes some imagination to see the parallel to a terminal box. With Belimo’s introduction of the electronic Pressure Independent Valve, the similarity is obvious. Stable control – system is “rightsized”. Occupant comfort and energy efficiency are improved. Spaces at or near design.

Pressure Independent Control Valve
What is a pressure independent control valve? A PI Control Valve…. Is a 2-way control valve that supplies a precise flow at any given control signal… Regardless of pressure variations in a system. It is not just a control valve and flow limiting circuit setter in the same assembly! Note: Automatic or manual balance valves should NOT be used with PI valves. If they are already installed they should be set WIDE OPEN. With the PICCV, the position of the actuator is set by the controller. An integral pressure regulator “trims” the differential pressure (and therefore the flow) to the required value. An ePIV works exactly like a pressure independent VAV box. The controller requests a given setpoint for flow and the integral flow loop measures and moves the actuator to maintain that exact flow from some minimum to some maximum pre-defined value.

Pressure Dependent Control Valve
Flow rate through equal % globe valve as a function of differential pressure (Cv = 1.9). *This assumes there is no balancing valve OR the balancing valve is left wide open.* Notice the line where the valve is wide open (top line). When the dP is at 5 psid, the flow is 4.2 GPM. With the valve still wide open, when the dP is at 30 psid the flow is 10 GPM! A 238 % increase in flow from 5 – 30 psi! At 50 psid (not shown) flow would increase to 13.4 GPM, a 319% increase!

Pressure Independent Control Valve
Flow rate through PI Control Valve as a function of differential pressure (3 GPM valve plotted). Equal % characteristic. Notice now on the PI control valve that the flow remains relatively constant over the entire 5 to 30 psid range. Also notice the increasing gap from 60% to 80% to 100% open. This is due to the equal % flow characteristic of the PI valve, which directly offsets the coil heat transfer characteristics to deliver a linear coil heat output response relative to the control signal.

Equal % Valve Characteristic
100 90 Energy Characteristic of Coil 80 70 60 Coil Energy Output (%) 50 Flow Characteristic of Equal % Control Valve 40 Resulting Energy Output of Coil 30 20 The idea of an equal percentage valve for water control of a coil is that the valve characteristic is exactly the opposite of the coil energy output characteristic. That is to say, as the energy output of the coil will rise quickly, relative to the flow. With the equal % valve, the valve flow is retarded in that same manner, but inversely proportionate to the coil energy output. In this way, the result is that the coil energy output is more linear with the control signal allowing better control of the process. 10 10 20 30 40 50 60 70 80 90 100 Signal (%) ASHRAE 2008 HVAC Systems and Equipment Handbook pg. 46.8

Advantages Iowa Energy Center Pressure Independent Valves Study
Chilled Water Closed Loop Test SAT Setpoint Change PICCV Valve Water Flow Globe Valve Water Flow How often will a coil be at design condition requiring full flow? As we know, historically we’ll be at design condition 1-5% of the time. We can also see this ‘full flow’ Waste Zone during any time the sensed temperature falls outside of the proportional band causing the valve to fully open. We could see this condition at morning warm-up or night low limit. What about the majority of the time the control valve is modulating under control? Once you’re satisfied, the modulating control valve will typically be open much less than 100%. But, there’s still a Waste Zone that needs to be addressed, even at this part load condition. This is testing conducted at the Iowa Energy Center whose mission is to evaluate means of energy conservation and its associated equipment. On the left is the setpoint changes made during the testing. Approximately every 90 minutes the supply air setpoint was raised 5 DegF. On the right is the resultant flow though the globe valve. You would expect to see something of a bump occurring upon a change in setpoint. As we start, the supply air setpoint is at its lowest, 56 DegF. The globe valve load is somewhat steady as it’s at a full load. As the supply air setpoint is raised, ultimately to 68 DegF, the valves are now under a partial load and you see the valve oscillating. This occurs because the valve is losing its authority at partial loads and the result becomes over (and underflow) through the valve and coil. A ‘partial’ Waste Zone because you still have to pump this excess water – and – the ‘unused’ chilled water is dumped back into the chilled water bypass ultimately effecting the operation of the chillers as we’ve seen. The Pressure Dependent Valve loses authority at part load. In effect, it becomes “Oversized”

Advantages Energy saving potential Globe Valve PI Control Valve
Because the PI valve oscillates far less than the PD valve, the net result is also that the control system loop is much more stable and less wear and tear of control valve and actuators occur. This is because the PI loop is effectively “pressure independent” of the dP across it. This changing dP occurs in any hydronic system as changes in flows across other valves are reflected in the changes in the system dP. Which of course, also means the pump(s) dP control loop oscillates less, therefore keeping the whole hydronic system pressure more stable.

Totalized Flow over 24 Hrs
Advantages Energy saving potential Totalized Flow over 24 Hrs Globe Valve = gallons PI Control Valve = gallons In this particular study, the totalized flow of the pressure dependent globe valve compared to the pressure independent characterized control valve was 26.5% greater during this 24 hour period! This represents a huge opportunity for savings. Note: The over-flow and under-flow cycling of this control valve results in a net over-flow condition!

Advantages Energy saving potential Pump Affinity Laws HP = Horse Power
Globe Valve PI Control Valve Pump Affinity Laws HP = Horse Power GPM = Flow in Gallons/Minute Required pumping horsepower varies as the cube of the flow. Therefore, this 26.5% increase in flow relates to double the required pumping horsepower. This only relates to the pump energy required. We have not even addressed the chiller inefficiencies on chilled water systems due to the low delta T that would be associated with this overflow. Globe = gallons PI Control Valve = gallons A 26.5% increase in flow results in twice the horsepower requirements from the pump.

Pressure Dependent Control Valves
Pressure Differential Sensor Setpoint = 10 psid Pressure Dependent Control Valves Design: 400 Ton / 800 GPM CHW 12˚ΔT Coil # gpm 10ft H2O (4 psid) 10 psid 2 psid 4 psid Coil # gpm 10ft H2O (4 psid) 20 psid 12 psid 4 psid Coil #2 gpm 10ft H2O (4 psid) 30 psid 22 psid 4 psid Coil # gpm 10ft H2O (4 psid) 40 psid Let’s look at the impact of poorly controlled flow on the Chilled Water System a bit more closely. Here is our simplified CHW system, and as we can see the design flow for the entire system is 800 GPM. If we select a design CHW ΔT of 12˚F, that makes this a 400 ton system. The chillers are capable of operating in a lead/lag and staged for full load. For this simplified plant, there is no chiller redundancy. 32 psid 4 psid Chiller 200 tons VFD-Pump Chiller 200 tons VFD-Pump

Advantages Energy saving potential
To see how we got 400 tons, here is the formula. Obviously, we selected a waterside ΔT of 12˚F. to make the math simple. The key thing to note on this slide is that for a given load, flow and ΔT are inversely proportional; as flow increases, waterside ΔT drops. As flow decreases, waterside ΔT increases. For a given load, flow and ΔT are inversely proportionate. As flow increases, ΔT drops.

Pressure Dependent Control Valves Design: 400 Ton CHW System @ 12˚ΔT
Pressure Differential Sensor Pressure Dependent Control Valves Design: 400 Ton CHW 12˚ΔT Coil # gpm Coil # gpm Coil #2 gpm Coil # gpm So going back to our system, let’s see how overflow affects the system. ADVANCE Let’s start by looking at the building side of the system. Chiller 200 tons VFD-Pump Chiller 200 tons VFD-Pump

Advantages Pressure Dependent Control Valves Design: 400 Ton CHW 12˚ΔT 180 Ton Load (45%) Coil # gpm Hold the load constant and vary the flow. Coil # gpm Coil #2 gpm In this system, at 45% load, if the system worked as designed and we were able to maintain our design ΔT of 12˚F., we’d be flowing 360 GPM. But as we’ve seen, pressure dependent valves are unable to accurately control the flow through the coils. ADVANCE To see the impact of poorly controlled flow on the chilled water system, let’s hold our load and our CHW supply temperature constant, and vary our flow to see what happens. Of course, in real life, loads are never constant, which is one of the factors that makes this so hard to see on a live system. Coil # gpm (12˚ΔT) 42˚ 54˚ CHWS CHWR 360 GPM Loop Flow

Design: 400 Ton CHW System @ 12˚ΔT Pressure Dependent Control Valves
Advantages Design: 400 Ton CHW 12˚ΔT Pressure Dependent Control Valves 180 Ton Load (45%) Coil # gpm Coil # gpm Coil #2 gpm As we’ve seen, for a given load, flow and ΔT are inversely proportional, so any overflow causes a proportional decrease in ΔT. So if our pressure dependent valves allow 10% more flow in the loop than ideal, our return water starts to go back to the plant colder than design. ADVANCE This overflow can happen at any load condition; it’s really just a mismatch between the amount of warm air flowing over the coil (our load) and the amount of cold water we’re pumping through the coil. We’re not getting any real benefit from the extra water, it’s just being pumped around the system without doing any work for us. And as we’ve seen, even a small increase in flow results in a major increase in pumping power. To the extent that this overflow creates a radical enough shift in “off coil” temperature, the control system will correct. But, one correction causes another to correct and another to correct, etc. causing system instability from other valves, pressures and pump control. Coil # gpm (10.9˚ΔT) 42˚ 52.9˚ CHWS CHWR 396 GPM Loop Flow (+10%)

Advantages Design: 400 Ton CHW 12˚ΔT Pressure Dependent Control Valves 180 Ton Load (45%) Coil # gpm An increase in flow results in: Lower return temperature. Reduced ΔT. Increased pumping power. Coil # gpm Coil #2 gpm At 15% overflow, which we’ve seen is easily possible with pressure dependent control valves, we’ve dropped our CHW return temperature from 54˚ down to 52.4˚, and our water side ΔT from 12˚ to 10.4˚. All that extra water is spinning around the system to no good effect. But that’s only 1.6˚ less than design. Surely that can’t be so bad, can it? Coil # gpm (10.4˚ΔT) 42˚ 52.4˚ CHWS CHWR 414 GPM Loop Flow (+15%)

Pressure Differential Sensor Pressure Dependent Control Valves Coil # gpm Coil # gpm Coil #2 gpm Coil # gpm Actually it’s pretty bad. If our water side design ΔT is 12˚, and we’re only getting 10.4˚, that’s a reduction of about 13% ({12˚-10.4˚}/12˚=0.133). If our water side design ΔT is 12˚, and we’re only getting 10.9˚, that’s a reduction of about 9% ({12˚-10.9˚}/12˚=0.091). ADVANCE But to fully realize the impact of low ΔT on the system, we have to turn from the building side to the plant side. With a 10% overflow ΔT Reduction goes From 12°F (Design) To 10.9°F (Actual) A reduction of 9%. With a 15% overflow ΔT Reduction goes From 12°F (Design) To 10.4°F (Actual) A reduction of 13%. Chiller 200 tons Chiller 200 tons

Advantages Pressure Dependent Control Valves Design: 400 Ton CHW 12˚ΔT 180 Ton Load (45%) 360 GPM Loop Flow CHWS CHWR 42˚ 54˚ (12˚ΔT) Chiller 200 tons VFD-Pump KW=1.0k 90% Load Arbitrary Value Again, we’ll start with an 45% load with the ideal amount of flow, 360 GPM, which results in our design 12˚ΔT. Each chiller and pump is sized for the full design load of the system, so the lead pump and lead chiller are humming along at 90%. We’ve got just enough water to serve our load, and it’s doing all the cooling work that we want it to do. Notice that we show a pump power of KW=1.0k. We’ve picked a variable, k, to represent the pumping power at 360 GPM because there are just too many possible pump selections for us say what a “typical” pump power consumption at 360 GPM. ADVANCE Just like before, we’re going to hold the load constant and vary the flow to see what happens. Chiller 200 tons VFD-Pump Hold the load constant and vary the flow.

Pressure Dependent Control Valves
Advantages Pressure Dependent Control Valves 180 Ton Load (45%) 396 GPM Loop Flow (+10%) CHWS CHWR 42˚ 52.9˚ (10.9˚ΔT) Chiller 200 tons VFD-Pump KW=1.33k 90% Load (396GPM/360GPM)3 = 1.33 (33% increase in pump power!) Once again, the inability of the pressure dependent valves to accurately control the flow results in an overflow condition, allowing 10% overflow to occur. Nothing changes for our chiller; it’s still providing 180 tons of cooling, and running along at 90% loading. But remember from our earlier discussion, the pump affinity laws dictate that the pumping power varies with the cube of the flow. So our little 10% increase in flow has increased our pumping power by more that 33%! Again with no real benefit. Now, if our overflow increases to 15%... Chiller 200 tons VFD-Pump An increase in flow results in: Lower return temperature. Reduced ΔT. Increased pumping power.

Advantages Pressure Dependent Control Valves Design: 400 Ton CHW 12˚ΔT 180 Ton Load (45%) 414 GPM Loop Flow (+15%) CHWS CHWR 42˚ 52.4˚ (10.4˚ΔT) Chiller 200 tons VFD-Pump KW=0.76k 45% Load An additional pump and chiller were started to meet the flow demand, not cooling demand! (414GPM/360GPM)3 = 1.52 (52% increase in pump power!) What happened?! What happened is that we exceeded the flow capacity of one pump and one chiller. Even though the lead chiller never exceeded 90% loading, you can only pump so much water through a chiller, and our pumps are sized for that maximum chiller flow. In effect, we ran out of water before we ran out of cooling. Now instead of running one chiller and one pump at close to full load, we’re running two pumps and two chillers at less than half capacity. It’s not too hard to see the waste here. ADVANCE Now, as I said at the beginning, this is a simplified system diagram, stripped down so that we can get to the key points. There are any number of possible system configurations and even more possible start-up and shut-down sequences of operation. But none of that changes the simple truth that if you can’t provide design ΔT to your chillers, you can’t get the design tons of cooling out of them. You wind up having to run your central plant to supply the building’s need for water, not it’s need for cooling! At higher load conditions (closer to 100%), the same sequence of events occurs (the lag chiller and pump are started too early at too low a load), but it will happen more quickly. At lower load conditions, the overflow in the loop may not reach the point where the lag chiller/pump have to be started. But you will still be wasting pump energy by pumping more water without getting any benefit from it.) Chiller 200 tons Chiller 200 tons VFD-Pump KW=0.76k 45% Load Also, a chiller receiving cold return water can’t load up!

Belimo PI Valves PICCV ePIV ½” – 2” 2 ½” – 6” 0.5 GPM – 100 GPM
Two Solutions for Today’s Hydronic Systems Here are the two types of PI Valves Belimo produces for the Commercial HVAC Market. The PICCV is a screw type valve up to 2” while the ePIV is a flange type valve for 2-1/2 to 6” The PICCV regulates flow based on an internal pressure regulator that takes a differential pressure across the ball. The ePIV regulates flow by having an internal magnetic flow meter and smart actuator. PICCV ½” – 2” 0.5 GPM – 100 GPM ePIV 2 ½” – 6” 105 GPM – 713 GPM

(Equal % or Linear; factory or field selectable)
Belimo Pressure Independent Valves Commissioning Belimo offers two products in their PI line. The PICCV utilizes internal pressure regulator technology. The DDC controller sets the valve stem open position (via the actuator positioning) and the internal regulator trims the flow as needed to maintain flow irrespective of ΔP fluctuations across the valve assembly. The PICCV can be field programmed to custom flow rates. The ePIV utilizes smart actuator technology with a built in magnetic flow meter. The ePIV allows field modification of several internal variables such as design flow setpoint, equal % or linear response characteristic, bias flow adjustment for “calibrating” flow (exactly as is done with the flow coefficient on a pressure independent VAV box) by the balancer if desired. PICCV (Equal %) ePIV (Equal % or Linear; factory or field selectable)

Belimo PI Valves PICCV Water passes through regulator Pressure is P2 (intermediate) Water exits valve Pressure is P3 (low) Water enters valve Pressure is P1 (high) Ports sense pressure drop and transfer it below regulator Low pressure pulls regulator down, against the spring force

As per the previous slide and this diagram, the audience should now understand and (for those who know the Phoenix air valve product) will see the similarities.

Belimo ePIV Magnetic Flow Sensor Smart Actuator Flow Feedback and
Here’s the Belimo ePIV showing the flow sensor, pressure transmitter; the control valve; and the actuator. To use this in your system you will only need one point for control (an analog output, for instance), that you already have for your valve control. An additional input point at the controller would be required to accept the feedback signal to monitor the actual valve flow in GPM. Flow Feedback and Control Signal LGCCV Valve

Magnetic Flow Sensor Measures changes to the induced voltage of a conductive fluid through a controlled magnetic field. No moving parts or openings to clog or jam. No maintenance. A magnetic flowmeter determines the flow by measuring the changes in an induced voltage of a conductive field though a controlled magnetic field. Why a magnetic flowmeter? No moving parts No orifices, paddles or other mechanical devices No maintenance

Flow Accuracy +/- 6% of Vnom
Actuator/Flow Tolerances Controller starts to control if delta "flow actual value" and "flow set value" > 5% (50% of the Flow tolerance) Controller stops to control if delta "flow actual value" and "flow set value" < 1% (10% of the Flow tolerance) Control actually allows incremental “float” to prevent over-response. This allows system to stabilize easier. Flow Accuracy +/- 6% of Vnom Example Control Signal Y = 100GPM (stable  no changes) If the measured Flow is higher then 105GPM  Actuator will correct until measured Flow is 101GPM. If the measured Flow is lower then 95GPM  Actuator will correct until measured Flow is 99GPM.

Installation Considerations
5 straight pipe diameters before the flow sensor no straight pipe requirement on the outlet of the valve Piping requirements for the ePIV are simple. 5 straight pipe diameters on the ePIV assembly inlet 0 straight pipe diameters on the ePIV assembly outlet You could attach an elbow at the ePIV outlet without any problem, for more installation flexibility. STRAIGHT INLET LENGTHS 2-1/2” ePIV = 12.5” 4” ePIV = 20” 6” ePIV = 30” 3” ePIV = 15” 5” ePIV = 25

Installation Considerations
The ePIV assembly can be mounted in any orientation, except, where the actuator would be below the horizontal of the ePIV. This is required to prevent condensation from running down into the electronic actuator. Vertical mounting of the ePIV is permitted. Actuator must be kept above horizontal!

Introducing – the ePIV electronic Pressure Independent Valve
Cost effective flow sensor technology combined with Belimo’s industry leading intelligent actuators and proven characterized valve technology Both non-spring and electronic fail-safe proportional models Provides all the benefits of PI valves (accurate flow control, improved efficiency at part load by reduced pumping power, improved waterside ΔT) Reduced cost, less weight, less raw materials, more sustainable! True flow measurement, available to DDC system through feedback wire Glycol concentration up 50% has no effect on flow measurement Can be configured for either linear or equal percentage flow characteristic with a simple program change. Cost effective Pressure Independent Technology coupled with current known valve technology with non-spring and electronic fail-safe proportional models We are cost competitive verses the competition – Flow Control Industries (DeltaP), Warren Controls, and FlowCon (to name a few.) The CCV technology is well known to Belimo as we have provided this for over 10 years. Known benefits of PI valves (no overflow, no underflow, non-hunting system) Since this is an extension of the PI technology – all the benefits that we have spoken about in the last 6 years for PICCV apply to this valve. Real flow measurement, display through feedback This is read through the PC tool or through the feedback wire at the controller. Will provide tables that show the flow at the various voltages (2V=XXX, 3V = XXX, etc.) Glycol concentration has no effect on flow measurement (within the tolerance of the system.) This is a major point for those who are familiar with flowmeters. We have already factored in the 0 to 50% glycol, as well as the temperature range into our flow tolerance. There are no settings to be done with the ePIV. Just install and wire as you would a standard actuator.

Belimo Field Programming Tool
Field adjustable programming tool allows: PICCV Control/feedback signal Custom flows/adjust flows Many other parameter adjustments ePIV Custom flows/bias adjustment Flow coefficient Equal % or linear setting ZTH-GEN The ZTH-GEN is a handheld device (fits in the palm of your hand) that provides easy field adjustment of the PICCV or ePIV. The device plugs into the actuator with the supplied cable. The device is powered by the actuator through the plug. No additional, external power supply is required. No external power needed; no battery; powered by actuator 24 vac! Just plug it into actuator.

ePIV adjustments (PC Tool v3.5 and above)
Belimo PC Tool ePIV adjustments (PC Tool v3.5 and above) Control/Feedback Signal Voltage 2-10 VDC 0-10 VDC User selected Flow Characteristic* Equal Percentage Linear Maximum (Design) Flow Bias Adjustment Belimo’s PC-Tool software (Windows based) is available for programming of the actuator. The PC-Tool (among other things) can adjust: The control signal input 2-10 vdc 0-10 vdc User adjustable Flow characteristic Equal percentage (default) Linear The maximum flow of the ePIV (Vmax) Bias Adjustment (just like the K-factor on a PI VAV Box)

Commissioning Additional P/T PORT for verification of 5 psi (11.5 ft H20) minimum differential across the PI Valve. Belimo developed a commissioning procedure with the input from the National Environmental Balancing Bureau (NEBB) and the Testing Adjusting Balancing Bureau (TABB). First, Belimo Pressure Independent Valves do not have any means of testing as part of the PI Valve. The consensus from a variety of engineers and owners was a reluctance to use the device you are testing as the means of testing the device is functioning correctly. Thus, the procedures detailed in Belimo’s documentation lists common and accepted flow verification procedures to verify the operation of the device. (ADVANCE) It’s good piping practice, and strongly recommended, that P/T ports be installed before and after a coil. (Many times these were eliminated when ports are seen on PI Valve, but those ports won’t allow later in life testing for issues, e.g. – pressure drop of the coil itself or the inlet and outlet temperatures of the coil). These p/t ports are typically standard on coil details. (ADVANCE) Also, a third P/T port, located after the PI Valve should be installed. All PI Valves, though pressure independent, require a minimum differential across the PI Valve to be pressure independent. If this minimum differential is not met, the valves will exhibit low flows, acting in most cases as a pressure dependent valve. (Belimo valves have a standard minimum differential of 5 psi; not uncommon today’s pressure dependent valves + you don’t need the pressure drop of the balancing valve when calculating your pump head because it is gone.) For sizing purposes, calculate a pressure differential of 5 psi for the Belimo PI Valves. The purpose of this third P/T port is to allow easy testing of the 5 psi minimum differential. Minimum ΔP across valve must be verified with PI valve COMMANDED by DDC (or by programming tool) to design flow, not manually positioned!

Commissioning Step 1: Ensure all strainers are clean and bypass valves are closed. Step 2: Command via DDC all PI valves to design flow. (Diversity assumed at 100%.) Step 3: Set distribution pump(s) to elevated speed by commanding ΔP setpoint or pump speed directly. Step 4: Find the “critical zone” (ie. the PI valve that has the least ΔP). Step 5: Increase or decrease pump speed/ΔP setpoint until critical zone has just over 5 psid (11.5 ft H20). The resulting ΔP at the system sensor will be the optimum system ΔP setpoint. Step 6: Verify total system flow is at design at main flow station (or by other method). Step 7: If flow is not within +/- 10% of design, start checking valves at terminal level, starting with largest valve(s) first (voltage, control signal, strainer, etc.) Belimo developed a commissioning procedure with the input from the National Environmental Balancing Bureau (NEBB) and the Testing Adjusting Balancing Bureau (TABB). First, Belimo Pressure Independent Valves do not have any means of testing as part of the PI Valve. The consensus from a variety of engineers and owners was a reluctance to use the device you are testing as the means of testing the device is functioning correctly. Thus, the procedures detailed in Belimo’s documentation lists common and accepted flow verification procedures to verify the operation of the device. (ADVANCE) It’s good piping practice, and strongly recommended, that P/T ports be installed before and after a coil. (Many times these were eliminated when ports are seen on PI Valve, but those ports won’t allow later in life testing for issues, e.g. – pressure drop of the coil itself or the inlet and outlet temperatures of the coil). These p/t ports are typically standard on coil details. (ADVANCE) Also, a third P/T port, located after the PI Valve should be installed. All PI Valves, though pressure independent, require a minimum differential across the PI Valve to be pressure independent. If this minimum differential is not met, the valves will exhibit low flows, acting in most cases as a pressure dependent valve. (Belimo valves have a standard minimum differential of 5 psi; not uncommon today’s pressure dependent valves + you don’t need the pressure drop of the balancing valve when calculating your pump head because it is gone.) For sizing purposes, calculate a pressure differential of 5 psi for the Belimo PI Valves. The purpose of this third P/T port is to allow easy testing of the 5 psi minimum differential.

Commissioning Belimo PI valves do NOT require that the entire system be placed in full design flow. Each PI valve flow can be verified individually with the rest of the system under normal control. Command valve assembly to design. Verify at least 5 psid across PI valve assembly. Verify coil flow as per usual method (coil ΔP method, etc.) Link for PI valve commissioning document: Belimo developed a commissioning procedure with the input from the National Environmental Balancing Bureau (NEBB) and the Testing Adjusting Balancing Bureau (TABB). First, Belimo Pressure Independent Valves do not have any means of testing as part of the PI Valve. The consensus from a variety of engineers and owners was a reluctance to use the device you are testing as the means of testing the device is functioning correctly. Thus, the procedures detailed in Belimo’s documentation lists common and accepted flow verification procedures to verify the operation of the device. (ADVANCE) It’s good piping practice, and strongly recommended, that P/T ports be installed before and after a coil. (Many times these were eliminated when ports are seen on PI Valve, but those ports won’t allow later in life testing for issues, e.g. – pressure drop of the coil itself or the inlet and outlet temperatures of the coil). These p/t ports are typically standard on coil details. (ADVANCE) Also, a third P/T port, located after the PI Valve should be installed. All PI Valves, though pressure independent, require a minimum differential across the PI Valve to be pressure independent. If this minimum differential is not met, the valves will exhibit low flows, acting in most cases as a pressure dependent valve. (Belimo valves have a standard minimum differential of 5 psi; not uncommon today’s pressure dependent valves + you don’t need the pressure drop of the balancing valve when calculating your pump head because it is gone.) For sizing purposes, calculate a pressure differential of 5 psi for the Belimo PI Valves. The purpose of this third P/T port is to allow easy testing of the 5 psi minimum differential.

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