Pumps With High IQs
January 8, 2013
It's all about performance. Adding a smart pump to a radiant or water circulation system can boost efficiency and comfort levels. So what makes a "smart pump" a smart pump?
The term "smart pump" has been used to cover a broad range of products, said Mark Chaffee, director of marketing, residential products, Taco Inc., Cranston, R.I. "When people say smart pump, it usually means that they are not just applying power to it and then letting it go 100 percent and turning it on and off."
Many smart pumps are actually pumps powered by "smart motors"-high efficiency electronically commutated motors, Chaffee said. Then there is what is redefining smart pump. "Along with high efficiency motors, now let's make the pump itself smart. Let's have that pump react to what's happening in the system. Let's make the entire system more efficient. "
From a Grundfos perspective, what makes a smart pump smart is software integral to the pump control, said Bob Reinmund, senior product specialist, small circulators at Grundfos Pump Corp. "The software recognizes changes in the pump demand, be it head or flow, and adjusts the pump operation accordingly."
With the ECM that comes with Grundfos ALPHA and MAGNA pumps, you automatically get an associated electronic brain. "What we've done is add software to that brain which recognizes changes in demand and adjusts the pump performance accordingly. The control is internal; there are no external set points or controls that the contractor or end user need to set up or input."
In the old days, with variable speed, you had an induction motor, and then you had an external control-a variable speed drive or some sort of control-and the contractor would have to go in and set a number of set points on that control to dial in specific requirements for that application, Reinmund said. "Our smart pumps take out take complexity and all the contractor has to do is apply power and make sure it's the right application, because our software recognizes the operating conditions and automatically adjusts the pump performance."
In a radiant heating application, a smart pump would recognize one zone calling for heat and fire at the minimum requirement for one zone, Reinmund explained. Then, as other zones open up and call for heat, the pump would speed up and provide the appropriate amount of flow rate for the multiple zones. Essentially, the pump speeds up or slows down based on operating conditions and/or demand.
With a fixed-speed pump in that radiant same application, the pump may try to give it 12 gpm when, in fact, it only needs two- or three gpm. "It is wasting all of that energy by providing high flow rates that are not required, there's probably a noise issue, and obviously, you are wasting electrical power. A smart pump would recognize that only one zone is calling for heat, slow the pump down, not waste energy and provide the appropriate amount of flow rate for one zone," Reinmund explained.
Smart pumps also come in versions that work based on temperature differential. "When you design the radiant system, you do the sizing based on a temperature drop across that system said Mark Chaffee, marketing director, Taco, Inc. "It's usually a 20-degree drop. What that says is, only on the coldest day of the year, I'm going to bring my boiler up to max temperature, maybe 180 degrees, and I'm going to put all of those BTUS out into the living space. If my temperature goes out at 180 degrees, it's going to come back at 160 degrees and everybody's going to be happy.
"Every other day in the year, if you put out 180 degrees Fahrenheit, the structure can't take that many BTUs; it's not losing that much heat through the walls and the windows. So, you have a couple of different options. You have the boiler reset where you can lower the boiler water temperature or, now you get into the smart pump side of it.
Taco's Bumble Bee and Viridian pump lines, sized for residential and commercial applications, monitor temperature differential via two sensors, one on the supply and one on the return, Chafee said. "The pump says, wait a second. If you are making all of these BTUs, why don't I speed up and slow down the pump to always deliver exactly what's needed for heat to the structure? That's what we say is a true variable speed."
For hot water recirculation, the smart pump creates an algorithm that memorizes use patterns, Reinmund said. "Let's say you always get up and take a shower at 6 o'clock. A smart pump would recognize that sequence of events every day of the week and automatically turn on say fifteen minutes or a half hour before and start the hot water recirc loop. When you get to the shower and want hot water, you automatically have it right away rather than letting the water run until it's hot enough and dumping all of that water down the drain."
First, it's smart to put in a hot water recirculation system, Chaffee agreed. "It's smart, green and economical. It makes more sense than to pay for the water, heat the water, move the water from the water heater to the faucet, and then dump it all down the drain waiting for the hot water to reach the faucet or shower. The U.S. government has estimated that the average family of four wastes about 16,000 gallons of water down the drain every year.
Because smart pumps can learn water usage patterns, Chaffee added, "Now what you are doing is not running the pump all the time, not moving water around the system the whole time, so you are saving generating the hot water and only delivering to fixtures when you're actually going to use it. Using a pump like Taco's Smart Plus pump makes the recirc system work that much better, electronically monitoring what is happening in system then delivering the best results to the occupants." Smart pumps in this application better meet the demand of high efficiency washers and dishwasher which work more efficiently if they start with immediate hot water.
Smart pumps also perform well in other applications, Reinmund said. "Any time that there is a change in head and/or flow-if you are pumping cold water or hot water-these same units would be a perfect choice. They automatically adjust the pump performance based off the head and/or flow requirements." For example, in a hotel, in the morning everybody's taking a shower, so you have an increase in hot water need. But you also have an increase in cold water demand. "When everyone leaves for work or checks out, there's a drop in demand and the pump would slow down accordingly, meeting those demands without wasting energy. Instead of pumping 100 gallons, it might pipe 20."
In terms of energy savings, "it's not the small amount saved by the energy efficient pump, it's the energy saved because the smart pump makes the system so much more efficient," Chaffee said. "You're using a component in a system such as a pump, in conjunction with monitoring what's going on in the entire system, to use less fuel. To deliver only the BTUs that are required to heat the building-no more, no less-and automatically adjust all the time to make sure that that happens.
"How much money do you spend on fuel a year? That can be thousands of dollars, easily. If you can save 10 to 15 percent of that number, and deliver a more comfortable environment, now that's smart. I don't know a homeowner who wouldn't say, make my system use less fuel so I pay less while at the same time I'm more comfortable."
Smart pumps should be an easy sell. "They can go in anywhere that you have radiant heating needs or pumping needs, with no special piping needs or other requirements, Reinmund said. "A cool feature of the ALPHA and MAGNA lines is a LED readout of power consumption in watts and gallons per minute estimation, Reinmund said. "Say you're on a troubleshooting call. There are probably three fundamental questions: Is there power applied? Is the pump actually pumping? Is hot water moving through the pump? Touch the discharge pipe. You can diagnose if it's a pumping issue in 15 to 20 seconds." Because smart pumps operate on demand versus constant pumping at full capacity, run life expectancy is doubled, if not tripled, Reinmund said.
In a residential application, depending upon your utility rate, the ROI on opting for a smart pump can be anywhere from nine months to a year and a half, Reinmund added. "Commercially, when you get into larger horsepower, I've seen situations with three months to a year payback. If the contractor has as discussion with the homeowner or building manager, and provides two options; say a fixed-stage standard induction motor, price being XYZ, and ECM type pump, priced at XYZ, and explains the differences between the two, the customer will opt for the ECM type motor because of the utility savings and the guaranteed comfort level."
In areas where energy costs are in the forefront, consumers are more likely to be looking for solutions like that provided by smart pumps, Reinmund said. "In Europe, where customers can face anywhere from 34 to 90 cents per kilowatt, they are always looking for ways to save energy. The European Union has an energy mandate that coming into effect January 2013 that all motors have to meet a certain energy efficiency. Currently, the only motor that would meet these standards is an ECM motor. The asynchronous motor is extinct in Europe in January 2013.There are agencies in the U.S. that are looking at ways to lower our energy consumption and this is the type of technology that they are looking at."
"I think this type of technology is going to become more and more prevalent and it is definitely the wave of the future. There are agencies looking at fractional horsepower motor efficiencies, and the only type of technology that can meet those proposed standards are pumps with ECM motors. This is coming from a national standpoint to help lower our utility footprint; it's a greener application and saves the customer utility dollars."