Last week the article covered pressure drop correction calculations. Today we offer you some handy charts to use for second glycol correction pressure drop. Example: I have calculated the water piping pressure drop through a chilled water system to be 80 feet using the System Syzer. Question: What is the pressure drop if I have 50% Ethylene Glycol/Water with temperatures of 45°F to 55°F? Answer: The average temperature is 50°F, so my factor is 1.47. [Read more…]
Pressure Drop Corrections for Glycol in HVAC Systems (Part 1)
Question: I have selected my piping friction loss based on water, but I am pumping a glycol solution. What correction do I use? Answer: There are three glycol corrections when designing a hydronic or process cooling system; heat transfer correction, pressure drop correction, and pump curve correction. This R L Deppmann Monday Morning Minute defines the second of three glycol corrections. [Read more…]
Circulator Pump Curves & Step Sized Selections. A Domestic Water Recirculation Example
Circulator series pumps are those small inline pumps that have fixed impeller choices with no impeller trimming available. When these pumps have ECM technology, the …
Primary-Secondary or Primary-Variable Heating Systems: Which System to Choose?
Primary-Secondary vs. Primary-Variable hydronic boiler pumping systems each have advantages for the engineer to consider. Most people in the industry are in one camp or …
Primary Variable Heating Systems: Should I Pump Into the Boiler or Out of It?
We recently received several calls for our recommendation on whether to pump into the boiler or out of the boiler in a primary variable heating …
Minimum Flow in a Variable Speed Pump: A Great Example
What is the minimum flow rate a variable speed pump can provide without damage to the pump? This is a question every engineer should ask …
Heat Pump Water Heaters – Will They Save the World?
Decarbonization and Electrification are two terms which may bring both fear and hope to plumbing engineers and gas fired water heater manufacturers. The hope is …
Solving Minimum Flow in a Primary Variable System (Part 3)
The engineer is aware of the importance of minimum flow to the pumps in hydronic systems. The R. L. Deppmann Monday Morning Minutes Part 1 …
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, …