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 …
The Department of Energy (DOE) Pump Standards – Now is the Time to Choose
The Department of Energy (DOE) pump standards goes into effect on January 27, 2020. This affects projects you are sending out to bid right now! …