Danfoss VFD Motor Efficiency Terms Bell & Gossett ECM Pump Variable speed centrifugal pumps in building heating, cooling, and plumbing systems use a …
Developing Variable Speed Pump Curves
Most heating and cooling pumps in commercial buildings operate in a variable speed mode. Today, we take your Monday Morning Minutes to explore the variable …
Three-way and Two-way Control Valve Basics in Hydronic Systems
Centrifugal pumps operate at the intersection of the pump curve and the system curve. Last week we developed the system curve for an example closed …
Closed System Curves in HVAC Hydronic Systems
A system curve is a graphical representation of how a heating or cooling system flow rate and system head might change as the load …
Condensing Boiler Specification – Part 6 – Variable Primary-Variable Secondary Example
Variable Primary-Variable Secondary pumping in hydronic heating systems has many advantages when this pumping method is chosen for the condensing boiler heating system. Today we …
Primary Secondary Piping Basics: Part 3 – The Common Pipe and Boiler Loops
Many boilers manufacturers recommend or suggest using a primary secondary arrangement rather than primary variable pumping. Often this piping scheme is suggested to avoid flow …
Primary Secondary Piping Basics: Part 2 – The Common Pipe (also Referred to as the Decoupler)
R. L. Deppmann Company receives calls about the size and the length of the common pipe just about every week. Gil Carlson, ASHRAE fellow and …
Primary Secondary Piping Basics: Part 1 – Terms
The basic design concepts of piping are important for a properly operating hydronic heating or cooling system. We have a great number of new engineers, …
Chilled Water Coil Temperature Reset in Cold Winter Months
Many facilities require cooling during the cold winter months. Northern climates such as Michigan or Ohio may not have any latent load in the cold …
Primary-Secondary CHW Loops with Unequal Flow Rates
Primary-secondary hydronic system loops have a common pipe that facilitates flow in both directions when the two loops have different flow rates. That same common …