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, …
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 …
Hydronic System Design – High Delta T Can Improve Boiler Efficiency (Part 2 of 4)
How can you increase the operating efficiency of your condensing boiler heating system? This question was raised in the last R. L. Deppmann Monday Morning …
Constant Speed 2-Way Control vs. Variable Speed Pumps for Heating and Cooling Coils (Part 2)
An engineer asked a question about using a variable speed pump for air temperature control in lieu of a two-way control valve. What are the …
Constant Speed 2-Way Control vs. Variable Speed Pumps for Heating and Cooling Coils (Part 1)
An engineer asked a question about using variable speed pumps for air temperature control in lieu of a two-way control valve. The question clearly makes you …
Hydronic Primary-Secondary Piping – How Important are the Two Close Tees?
Every year we get questions about the importance of primary-secondary piping rules around boilers and coils. Recently, I also received a call about using a …
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, …