Parallel pumping in hydronic systems can save energy and construction capital costs. Today we continue the series on parallel pumping where we look at the …
Parallel Pumping: What is it and Why do it
Most hydronic heating and chilled water systems end up with one operating pump and one 100% standby pump. It is easy to understand, and the …
HVAC Hydronic System Variable Speed Pump Operation
I am beginning a series on parallel staged variable speed (VS) pumps. As I write this series, it is important to understand and refer to …
HVAC Hydronic Pumps – Should I Trim the Impeller or Trim with Speed? (Part 2 of 2)
In the last R. L. Deppmann Monday Morning Minutes, I offered a couple of reasons why an engineer would schedule a larger impeller than needed …
HVAC Hydronic Pumps – Should I Trim the Impeller or Trim with Speed? (Part 1 of 2)
Engineers schedule a pump capacity in GPM and head along with the horsepower. The pump manufacturer traditionally trims the impeller from the maximum size, also …
Hydronic Cold Fill Makeup Valve: Keep it Open or Closed?
The cold fill pressure setting in a closed hydronic heating or cooling system is still one of the key problems uncovered when our customer service …
Expansion Tank Air Side Maintenance Schedule
I recently visited a school mechanical room and was asked about the relationship between the makeup pressure reducing valve setting and the expansion tank pressure …
Centrifugal Pump Gauge Readout: Adjustments to Balancing for Glycol Temperature
Glycol correction factors were the subject of many of the last few R. L. Deppmann Monday Morning Minutes. While writing these articles, I thought about …
Centrifugal Pump Gauge Readout Corrections for Hydronic Glycol Systems
Ask any test/balance or service technician in the hydronic HVAC world to convert PSIG to feet of head and the multiplier of 2.31 is the …
Centrifugal Pump Gauge Readout Corrections-Velocity Head Corrections
We recently had an inquiry from an engineer who was concerned about pump operation compared with the submitted pump curve. It appeared from the balance …