Now That is One Smart Pump

By John Mesenbrink

Now more than ever energy efficient products are critical when trying to lower a building’s carbon footprint. And when it comes to water efficiency, pumps are the backbone of the building’s infrastructure. Today’s intelligent pumps carry the answers for water distribution.

As we delve into the world of smart pumps, Plumbing Engineer recently spoke with the major players in the pump manufacturing industry to get their perspective on today’s smart pumps and the benefits their pumps offer to the overall HVAC system. The players are Mark D’Agostino, vice president of sales and marketing, WILO; Eugene Fina, product manager — commercial pumps, Taco; Joe Rice, product manager for Grundfos; and Mark Handzel, director of Xylem building services marketing.

PE: In today’s energy efficient HVAC market we hear a lot about “smart pumps.” What exactly does the term mean?

Mark D’Agostino/WILO: The term “smart pump” is derived by the pump’s ability to “learn” what the system is doing and react accordingly. For example, with a typical asynchronous pump, it runs at full speed regardless of system demand. Think of it like a car that we push the accelerator to the floor continuously and regulate our speed with the brake pedal. In essence that is the current logic in hydronic pumping. We utilize pressure compensated bypass valves, throttle valves on the discharge side of the pump or 3-way valves to act as the “brake” to deal with this unwanted, excess system velocity. The WILO Stratos pump “senses” the changes within the system (ie; zones opening and closing as demand varies) and automatically slows down or speeds up to react to this change much like cruise control.

The UL listed WILO Stratos is North America’s first commercial wet rotor circulator with an EC motor. With this revolutionary “smart pump” technology, the Stratos can achieve energy savings of up to 80% compared to a standard wet rotor circulator. The Stratos also offers flows from 10-285 USGPM, and 2-40' of head delivery. This “all-in-one” pump can offer constant pressure curves, inclining pressure curves, temperature controlled set points, an infrared communication module to any Windows mobile-based PDA, and is fully compatible with building management systems.

Fina/Taco: “Pump Affinity Laws” help us to evaluate what the savings are for most jobs. The laws say that the change in horsepower consumed is proportional to the cube of the change in speed. It’s all based on a mathematical formula. A smart pump, or a constant speed pump set up and balanced with a drive, consumes only 73 percent of design horsepower if it’s running at 90% of its top speed; a pump running at 50% of its speed consumes only 12.5% of its full energy draw. These are significant energy savings. Other benefits are that these pumps run at reduced speed, which extends their life, and they’re also soft-started. This puts less wear on pump and system components. These become an advantage for the equipment and the building owner.

With the focus on first cost, green construction and energy optimization, our industry needs advantages like these. The decisions we make about design Delta T and flow balancing can have a significant positive impact on system performance. A smart pump automatically responds to change in system demands and, most importantly, reduces its speed automatically when the demand is reduced. The Viridian is capable of doing this without the use of sensors. Taco’s 1900 VFD is used with differential pressure sensors for a Delta P system, or temperature probes for a Delta T system.
Rice/Grundfos: While variable speed motors are a huge efficiency over fixed-speed pumps, intelligent or smart pumps such as the Grundfos MAGNA™ represent an ability to automatically modulate circulator performance to match ever-changing system demand.

Exclusive to Grundfos, the variable speed wet rotor MAGNA circulator uses an integrated logic algorithm to ‘learn’ a system’s usage patterns to automatically determine the lowest possible operating efficiency point to maintain the desired temperature. By continuously finetuning power consumption and flow rates to meet the dynamic needs of the system, this AUTOADAPT function saves both energy and money. In live field tests of the product, independent contractors have experienced power savings up to 80 percent over conventional pumps.

From experience and several market studies, we know that the majority of installers never identify the specific details of the heating systems in which they install circulator pumps. Consequently, they find it hard to select the most efficient pump for the system and then to program it with the correct settings. For installers, the intelligent or smart AUTOADAPT function means that for approximately eight of every 10 installations, the pump will automatically select the optimal setting with no additional intervention needed — just set it and go. Said differently, the AUTOADAPT learning algorithm is the most efficient and effective pump system setting where the majority of head-loss is a result of piping friction versus zone valves.

While there is a price premium for smart pumps and motors integrated with variable speed technology, contractors should remember that power consumption represents 85 percent of a pump’s lifetime costs. Therefore, even the smallest improvement in energy efficiency can translate into sizeable cost savings over the 15-year average pump lifespan. In fact, some of today’s leading integrated, variable speed circulators offer payback in as little as two years.

Handzel/Xylem: Although contractors and building owners know that pumps play an important role in all HVAC systems, they sometimes overlook what a critical factor pumps can play in reducing operating costs and significantly increasing a building’s energy efficiency. However, new industry regulation initiatives now make it more important than ever that building owners look at the entire HVAC system to achieve more sustainable energy efficiency. To help building owners achieve this, smart pump design is a growing trend in the pump industry and more astute manufacturers are creating new designs to improve efficiency and reduce the total life-cycle cost.

As a global water technology company with 95 years of innovation, Bell & Gossett, a Xylem brand, created a double-suction, split-case, base-mounted centrifugal pump series with features never before offered in the HVAC industry. Aptly named the VSX Series (vertical split-case), the pumps are designed to provide unparalleled smart performance and reliability over a wide range of applications.

The industry experts told us they wanted smarter pumping solutions and we delivered a unique series of pumps designed to their specifications. The VSX pumps provide the ultimate in high efficiency hydraulic design, reliability, and installation versatility.

The VSX series can help building owners achieve these type of savings due to special product features such as multiple configurations for piping design flexibility and a 40% smaller footprint than a vertical in-line pump and static vertical load on flanges allowed.

PE: How does your company’s particular pump offer savings as it relates to water/energy efficiency?

Mark D’Agostino/WILO: The Stratos pump dramatically reduces energy consumption (by as much as 90% in some applications) by matching pump speed with system demand. A typical hydronic system is sized to the heaviest demand day. Circulators are then sized based on logic. In reality the system operates in this “heaviest demand area” less than 10% of the heating year. Therefore the circulator is bigger than it needs to be for greater than 90% of its actual operating life. By varying its speed, the Stratos products are only as “big” as the system requires it to be at any given point in its operating range.

The Stratos ECO is ideal for residential hydronic heating applications. The Stratos product line addresses heavy residential and light commercial hydronic heating & cooling applications. The Stratos D (dual Head / single volute model) is applied in heavier commercial hydronic heating and cooling applications. In Q1 2012 we will introduce Stratos Z, which is the same ECM Smart Pump Technology applied to a stainless Steel volute (NSF61/Annex G rated) for domestic water applications (ie Hot Water Recirc) and Stratos Giga (due Q3 2012) will address hydronic heating and cooling applications in much larger commercial systems.

Fina/Taco: The Taco Viridian is a web-enabled, high efficiency, wet rotor, variable speed commercial pump product line for chilled and hot water applications. All settings and pump access can be done over an Internet connection making installation, setup and service easy. The ECM motor saves up to 80% of the electrical energy compared with conventional pumps and its multiple operating modes fit most applications. The ECM based design combines a brushless electronically commutated synchronous motor with a strong permanent magnet rotor. An ECM motor does not consume any energy in order to magnetize the rotor and the position of the magnetic poles of the rotor and stator generate continuous thrust in the rotating direction of the rotor. The integral electronics precisely drive the rotor as fast as the rotating flux, significantly reducing motor efficiency losses while greatly increasing starting torque.

Taco’s new 1900 VFD close-coupled, in-line pumps with integrated variable frequency drives are designed to enhance pump and building efficiency. The single- or three-phase 1900 VFD line greatly increases energy efficiency and building comfort.

Taco 1900 VFD pumps are available in five basic models ranging in size from 11/2" 5 11/2" to 2" 5 2" with a flow range of 10 to 250 GPM, and head capability to 160 feet. Rear, pull-out design allows servicing of the pump without disturbing the piping.

The 1900 VFDs can be installed anywhere in the piping layout. They are self-supported by system piping, requiring no additional strapping or external support. Each can be mounted horizontally or vertically. The motor’s permanently sealed, grease- lubricated ball bearings make the 1900 Series pump virtually maintenance free.

Typically, the payback period for installing VFD pumps in place of single-speed pumps is less than 12 months. Because HVAC systems are rarely required to operate at full capacity, VFD pumps gently ramp-up and ramp-down operation to match system flow to actual heating and cooling demands, enhancing overall system efficiency.

Rice/Grundfos: Designed for hydronic heating applications in large residences, multifamily, institutional and light-commercial applications, the Grundfos MAGNA ECM (Electronically Commutated Motor) circulator features a permanent magnet motor that will cut power consumption by a minimum of 50 percent, as compared with other circulators in its class. The result is a dramatically more efficient motor that generates less heat and energy waste, while delivering a starting torque four times higher than a standard induction motor — a key feature should the circulator experience long periods of idleness.

By their very nature, heating systems fluctuate, so why use circulator pumps that cannot automatically optimize output to meet changing demand? Rather than running at a fixed speed all the time, the MAGNA pumps operate on a proportional pressure curve, which means you get only the pressure you need. Another way to think about proportional pressure is a means to compensate for head or friction loss in a heating system.

An energy-efficient, intelligent heating circulator with an ECM motor — such as the Grundfos MAGNA — uses up to 80 percent less energy than a conventional pump. This level of savings would cut around 10 percent off an average household’s annual electricity bill.

Ten years ago, when energy costs were not paramount, the conventional thinking held that it didn’t make sense to use variable speed drive technology on motors smaller than 50 horsepower (HP). Since that time, the industry discovered that energy and operational efficiencies should not be reserved only for large applications. After all, there are many more fractional HP pumps and motors in operation than there are large 100 HP applications.

Handzel/Xylem: Based on extensive Voice of the Customer outreach feedback, the pumps were designed to provide HVAC professionals with enhanced energy-efficiency, easier maintenance and a significantly smaller footprint. Some of the other unique ‘industry-first’ features include:

• Multiple suction and discharge flange configurations that maximize piping possibilities. The VSX connection options include the VSC model (Top Suction — Top Discharge flanges), VSCS model (Side Suction — Top Discharge flanges) and the VSH (Side Suction, Side-Discharge flanges).

• The hydraulic matching of the pump impeller and casing was achieved by utilizing Computational Fluid Dynamics (CFD). The result is a product offering superior performance in chillers, cooling towers, distributive pumping and a wide range of additional applications.

• Unique ‘Plug-n-Play’ capability that allows simple field modifications for mechanical seals and external seal flushing.