Modern Pump Selection Part 2: Theory Vs. Real World Operation of Variable Flow Pumping

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Modern Pump Selection Part 2: Theory Vs. Real World Operation of Variable Flow Pumping

In variable speed pumping systems, does zero load ever result zero pump speed?

Practically speaking, the answer is no.  In closed hydronic systems with 2-way valves there is almost always some amount of differential pressure created by continuous impeller rotation – even when....

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Solving Balance Issues with A Differential Pressure Controller

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Solving Balance Issues with A Differential Pressure Controller

What are your options when unbalanced circuits in an existing hydronic system are creating comfort issues due to underflow or overflow through coils?  We just spent the last twelve blogs describing the various methods for balancing a start-up system but do those same methods apply to existing systems and retrofits? 

The short answer is....

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Condensing Boiler Plant Piping Design & Control Part 7: Calculating Boiler Cycle Time

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How long should a boiler run before it cycles off? And how long should it stay off before it cycles back on? The answers to these questions will of course vary from system to system. As a general rule, the combination of boiler run time and off time should never be any less than 10 minutes. Under normal operating conditions, the run time will always be dictated by two factors....
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Condensing Boiler Plant Piping Design & Control Part 6: Boiler Cycling and Supply Delta T

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Identifying the stop and start range of a boiler system is a critical first step in controlling boiler staging and/or sequencing. This range defines what the boiler supply temperature is at full fire and what the supply temperature is at no fire. It is commonly referred to as the boiler supply Delta T.
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Condensing Boiler Plant Piping Design & Control Part 5: How To Size a Buffer Tank

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Not every boiler system requires a buffer tank – but some do. So how do you know if a buffer tank is needed for your particular boiler system or boiler plant design? A buffer tank is required when there is not enough water volume in the system to absorb the excess heat from the boiler during operation or during start-up firing....
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