Ashrae 90.1 and the future of pumping part 2

Editor's Notes

• #2: A long list of savings that adds up to a LCC and a true value based offering.
• #4: In a 3 pump system shown here (NOTE: We don’t show the VFDs on the wall or integrated on the motor) But we eliminate the flex connectors, the concrete bases, inertia pads, no realignment of the flex coupling during commissioning. HSC versus VIL Assume 3 pump system - 6x5x12 versus 6x6x11.5 (2-duty / 1-standby) Installation cost = $19,572 vs $8,327 105.7 sf vs 44.2 sf; diff. = 61.5 sf and if we assume $150 / sf, that’s $9,225
• #5: LEFT: BAYFRONT TOWERS, Tampa, FL Compact mechanical room with no space for two individual pumps and no space to mount drives on the wall. Simple single large AHU avoided using DP sensor by using sensorless design. Pumps also have auto alternating feature. Worked out of the box with only a slight adjustment to the minimum maintained pressure to accommodate the twin chillers minimum flow requirement. What is not shown in this picture is the two chillers and twin buffer capacity tanks and expansion control tank. There’s a lot of equipment in this little room! 4302 8x8x10-20 hp DualArm DE-IVS Sensorless unit we sold this past year. The DualArm IVS Sensorless pump has been in operation for almost ¾’s of a year. We took out an old water source Air Handler replacing it with a chilled water AHU, Twin Chillers, the IVS dual Arm, a buffer capacity tank, air purger and expansion tank all in the same room we took the old AHU out of…No small task. It worked right out of the box with only a slight adjustment to the minimum maintained pressure. The original set point was below the chillers minimum flow requirement. Otherwise – Flawless! RIGHT: SHOREWOOD PACKAGING, Danville, VA If no floor space, mount the pumps off the ground!! Commercial real estate cost $120/ sq ft, +50% Joe’s numbers on wall mounting?
• #6: The VILs present a huge opportunity for pipe savings as they can be mounted directly to the chillers, boilers, and cooling towers. On average the pipe savings are reduced by 40-50%. Here’s an example of a plant room optimization for Glendale Arena, home of the Phoenix Coyotes. On the left are HSC. On the right the VILs are mounted directly onto the chillers saving 43% of piping. In this case, the pipe savings pretty well paid for the pumps. Ran AOL 2400 gpm @ 50 ft vs 2400 gpm @ 80 ft and looked at difference in op cost. 14477 vs 7893 = $6600.
• #7: The most common replaced item on pumps is the mechanical seal. Seal changeout is much faster 30mins versus 2 hrs compared to base-mount. Also 4300 VILs don’t use bearings which dramatically reduces failures and maintenance costs.
• #8: A long list of savings that adds up to a LCC and a true value based offering.
• #10: Armstrong Vertical inline pumps with Design Envelope IVS integrated controls. Series 4300 pumps are available up to 350 hp with integrated controls. Series 4380 close-coupled pumps are available up to 7.5 hp with integrated controls.
• #11: The twin pump uses 2 rotating assemblies in 1 shared casing. The twin 4312 and 4392 use the same rotating assemblies as the 4300 and 4380 vertical inline pumps.
• #12: Casings differences.
• #14: Servicing of twin pumps is not as convenient as the dualARM; both pump rotating assemblies must be shutdown in order to begin maintenance of either seal. Since the twin pumps do not feature built-in isolation valves, the pumping unit must be isolated by separate external valving. While the 4312 split-coupled pump features an outside seal, and can be changed without removing the motor, the Series 4392 close-coupled twin pump requires installing a blank plate over one side of the pump casing before the rotating assembly can be accessed and the seal changed.
• #15: Twin pumps provide redundancy but require the system to be temporarily shut down (and the blank plate installed) to service a pump head. The dualARM, with its locking valves, can direct the fluid to the opposite pump head and continue to operate without shut down. For critical services that cannot afford down time, such as cooling for data centers and hospitals the dualARM should be used. The twin pump is available only in bronze-fitted construction rated for ANSI 125. The dualARM can be used in higher pressure services with ductile iron bronze-fitted construction for ANSI 250.
• #18: In some cases the flange to flange dimension is smaller than a single VIL!
• #20: A twin pump installation occupies almost four times less space than an installation with two end-suction base-mounted pumps. Compared to its dualARM counterpart, the twin pump’s installed footprint can use 20-30% less space.
• #23: We ’ ll look at traditional flow control with DP sensor – some of the strategies to get optimum energy savings at part-load. What are some of the pros/cons. Then we ’ ll go into an introduction to sensorless control that is a key feature of our Design Envelope pumps, how we do it, as well as why it presents advantages over sensors. After that, we ’ ll run a short clip of the sensorless display unit in action followed by a case study and then some questions.
• #24: If equipped with the IVS Sensorless feature, the pump’s performance curves against power and speed are pre-programmed into the controls. During operation, the power and speed of the pump are monitored, enabling the controller to establish the hydraulic performance and position the pump’s head-flow characteristic to the system requirements. As the building’s control valves open or close to manage load, the IVS Sensorless controls can intelligently slow down or speed up the pump to maintain the pressure setpoint. The built-in PID controller converts the pressure setpoint to head. Head squared is proportional to flow, flow is proportional to speed.
• #25: With variable frequency drives coming down in price and improved reliability over the years, the building industry has changed over to using variable speed pumps with 2 way valves. Instead of bypassing the excess flow, today we would slow the pump down to reduce capacity to the coil.   The mechanism to control the speed of the pump has traditionally been a sensor. The sensor would typically measure differential pressure or temperature of the system and have the variable speed controls respond by speeding up or slow down to control the pump.
• #26: In this simplified chilled water system example, our chiller and pump are found in the basement mechanical room and the pump distributes chilled water to the cooling coils. The building ’ s temperature controls are connected to control valves that manage the flow rate to the cooling coils (load). Traditionally, a differential pressure sensor would be installed across the line to measure the changes in pressure from the valves opening and closing. As the control valves open for more cooling, the system resistance is reduced and the differential pressure across the valve decreases. The variable speed controls react to this change by increasing the pump speed to maintain the pressure setpoint (or the desired pressure). If the control valves close to reduce the cooling output, the differential pressure across the valve increases, and the variable speed controls reduce the pump speed to maintain the pressure setpoint (or the desired pressure). “ desired pressure (the Setpoint) with the actual pressure (the Feedback) from a pressure sensor and adjusts the pump speed to maintain the pressure at the desired level. ” But there are a number of scenarios that come up when dealing with sensors; most notably is where to install the DP sensor. The common thinking suggests that the sensor be installed at the most remote load. Another is to keep things simple and install it in the mechanical room. Another is to install it at 2/3rds from the pump. There are benefits and disadvantages to each of these strategies in terms of energy consumption and installed cost and we ’ ll look at each of them in the next few slides.
• #29: In a chilled water system, a building ’ s temperature controls are connected to control valves that manage the amount of flow rate to the cooling coils. As the control valves open for more cooling, the differential pressure across the cooling coil, valve and piping will begin to decrease, and the IVS controls react to this change by speeding up the pump to maintain the pressure setpoint. If the control valve closes for less cooling, the differential pressure across the coil will increase, and the IVS controls slow down the pump to maintain the pressure setpoint. To ensure the coil is satisfied, a Minimum Head is introduced so that the pressure drop across this load is always satisfied. Our new pump performance curve is now the Control Curve (in blue). The Minimum Head is usually established in the field during the commissioning process by installing differential pressure sensors across the remote load and setting the minimum required head/pressure and wiring it back to the variable speed controls. In this case, the Minimum Head is the same as the design head which doesn ’t result in much energy savings; in fact this configuration won’t even meet the ASHRAE 90.1 energy standard – but it is very simple to install. The built-in PID controller converts the pressure setpoint to head Head squared is proportional to flow, and flow is proportional to speed
• #31: In a chilled water system, a building ’ s temperature controls are connected to control valves that manage the amount of flow rate to the cooling coils. As the control valves open for more cooling, the differential pressure across the cooling coil, valve and piping will begin to decrease, and the IVS controls react to this change by speeding up the pump to maintain the pressure setpoint. If the control valve closes for less cooling, the differential pressure across the coil will increase, and the IVS controls slow down the pump to maintain the pressure setpoint. To ensure the coil is satisfied, a Minimum Head is introduced so that the pressure drop across this load is always satisfied. Our new pump performance curve is now the Control Curve (in blue). The Minimum Head is usually established in the field during the commissioning process by installing differential pressure sensors across the remote load and setting the minimum required head/pressure and wiring it back to the variable speed controls. This configuration provides tremendous energy savings, meeting ASHRAE 90.1 standard for energy efficient operation – but it is difficult to install. The built-in PID controller converts the pressure setpoint to head Head squared is proportional to flow, and flow is proportional to speed There ’ s a lot to think about just on where to place the sensor to get maximum energy savings and to ensure all the loads are satisfied.
• #32: Comparison of the 2 strategies we just discussed. D = mechanical room sensor E = remote load sensor or Design Envelope Sensorless Why is the Design Envelope Sensorless the same performance as remote load sensor? (A: Because the Sensorless control can provide the same performance as a remote load sensor)
• #34: Armstrong innovated the Sensorless pump control technology which has been used in Europe for 15 years specifically for the HVAC industry. The Sensorless function acts as a “virtual sensor” and allows us to control the pump in the same way as sensor - only without the sensor.
• #36: With these 4 parameters, any point on the curve can be determined. Similar to a sizing selection program, if you input flow and head, you get as an output – power and speed. The sensorless control looks at its flow and head to calculate head and speed.
• #39: For simplicity, let ’ s look at 3 sample points and apply them in a pumping system to understand the details of how sensorless control works.
• #40: The slide is illustrating a system friction design curve [S1 System curve] A pump performance curve at full design speed (S1) is selected to intersect the system curve at the design flow and head conditions. The corresponding power drawn is shown below the performance curves. The control curve is set via the VFD graphical interface device by the input of the design flow, head and minimum system pressure (On the vertical [y] axis). As the building conditioned spaces reach the high tolerances levels for the set point conditions, the system 2-way control valves will modulate closed, increasing the resistance to flow and creating a new system resistance curve (Similar to the S2 System curve). This will cause the pump to move left on the S1 performance curve (1), and will pump less water because of the valves throttling to a higher pressure. The power at the new operating point will take less power (2) than the original operating conditions and the Sensorless Control logic recognizes that this power reading is incorrect for the current operating speed and thus reduces the motor speed (Pump curve S2) until the power and speed converge on the control curve (3 & 4). The unit will operate at the new operating point (3) at the reduced power (4) until the control valves react again to conditioned space environment change and modulate appropriately. Thus the IVS Sensorless Controlled pumping package will react in an identical manner to a pump controlled by feedback from a remotely mounted system DP sensor, without the need to purchase, install and wire the remote sensor.
• #41: The slide is illustrating a system friction design curve [S1 System curve] A pump performance curve at full design speed (S1) is selected to intersect the system curve at the design flow and head conditions. The corresponding power drawn is shown below the performance curves. The control curve is set via the VFD graphical interface device by the input of the design flow, head and minimum system pressure (On the vertical [y] axis). As the building conditioned spaces reach the high tolerances levels for the set point conditions, the system 2-way control valves will modulate closed, increasing the resistance to flow and creating a new system resistance curve (Similar to the S2 System curve). This will cause the pump to move left on the S1 performance curve (1), and will pump less water because of the valves throttling to a higher pressure. The power at the new operating point will take less power (2) than the original operating conditions and the Sensorless Control logic recognizes that this power reading is incorrect for the current operating speed and thus reduces the motor speed (Pump curve S2) until the power and speed converge on the control curve (3 & 4). The unit will operate at the new operating point (3) at the reduced power (4) until the control valves react again to conditioned space environment change and modulate appropriately. Thus the IVS Sensorless Controlled pumping package will react in an identical manner to a pump controlled by feedback from a remotely mounted system DP sensor, without the need to purchase, install and wire the remote sensor.
• #42: Generally if a system is overdesigned, the design point ends up drifting to the right of the curve. The head is lower than anticipated and the system needs to be balanced with a circuit balancing valve. Instead of introducing a restriction or a pressure drop in the form of a balancing valve, the Sensorless control curve can be adjusted through the keypad controls. There are 3 parameters built into the Design Envelope controls that define the control curve. Those are the setpoint (desired pressure) P20-21, the minimum head P22-87, and design flow P22-89. (Note that the Design Envelope pump would still work when the design point is over-estimated, however it doesn ’ t begin to reduce its speed until the system is operating below the pre-programmed design flow.)
• #43: *(Comparison of variable flow-constant speed operation to variable flow-variable speed operation) During a building ’ s commissioning, the pumps and 2-way control valves are installed. The control valves open and close as they would under normal operation but the controls contractor has not commissioned the sensors yet; this typically takes 3-4 months. The Design Envelope sensorless pump can react to the changes in system resistance from the valves opening and closing and adjust its speed to meet demand – as soon as it is installed. The savings during those first 3 months can payoff up to 14% of the pump cost.
• #44: Armstrong ’ s Sensorless control is currently only available for singe pump operation systems. It can be used for duty-standby operation but cannot do parallel pumping control. There are some complex control calculations required to stage multiple pumps off and on along a dynamic pump curve. However this feature is currently in development and should be available by the end of the year.
• #45: 2180 Yonge Street is a complex of three interconnected office buildings located in downtown Toronto. The complex includes a small shopping concourse, an office tower and a multiplex cinema. Constructed in 1972, the office tower offers 18 floors and a total of 402,277 square feet (37,373 m 2 ) of commercial office space. Armstrong supplied the pumps for the initial construction of this tower. At the time, Vertical In-Line Pumps were a relatively new, market-leading design.
• #47: Analysis of the original pumps showed they were oversized. Design Envelope IVS solution allowed the system designer to better match the performance of the pumps to the actual system conditions. Actual system Hdesign = 85 ft (53hz)
• #49: Today we ’ll be discussing….