The term “overspeeding” in pump selection and operation is a topic of conversation in the world of hydronic design. When asked about this subject I …
How to Pick an HVAC Centrifugal Pump Part 9: Over Speeding HVAC Pumps & Motors
There are times when a little more capacity or a little more safety factor is needed from a pump selection. Often, we are asked about …
Variable Speed Pump Control: Wheels and Ladders and Diversity
Commercial and industrial hydronic heating and cooling systems will usually have variable speed distribution pumps. There are multiple ways to identify what speed the pumps …
Variable Speed Systems: Types of Sensors (Part 2)
Last week, in part one of this series, we looked at temperature, pressure, and differential pressure sensors to control the speed of a HVAC or …
Variable Frequency Drives (VFD) and Single-Phase Power
As a representative for Danfoss VLT variable frequency drives (VFD), we often are asked about the use of the VFD when single-phase power is the …
Pumping From an Atmospheric Tank: Pump and Tank Control (Part 3)
Let me start by wishing everyone a Happy and Prosperous New Year. This blog begins the 14th year of the R. L. Deppmann Monday Morning …
Minimum Flow in Variable Speed Pumps for Building Hydronic HVAC Systems (Part 2)
The HVAC engineer designing a hydronic system understands the need to protect the circulating pumps from a dead head or no flow condition. This week, …
Minimum Flow in Variable Speed Pumps for Building Hydronic HVAC Systems (Part 1)
Every week a question comes into R. L. Deppmann about the minimum flow rate through hydronic pumps and the best way to achieve it. Today, …
Variable Speed Chilled Water Systems: Demand Reset
There are multiple methods to vary pump speed in HVAC chilled water systems. A common method is the use of a differential pressure transmitter at …
How to Limit the Speed of the Pump using a Danfoss Variable Frequency Drive
In this Service Tip of the Month, we demonstrate how to limit the speed of the pump using the Danfoss Variable Frequency Drive (VFD).