One of the most misunderstood concepts in pump selection for hydronic design is the net positive suction head or NPSH. Problems with NPSH can spell …
Open Cooling Tower System Pumps – Balancing the Pump Using a Drive
Open cooling tower pumps are traditionally operated as constant speed. When balanced, the extra pump head or over-heading is throttled across the discharge balance valve …
Balancing & Trimming Hydronic Constant Speed Pumps
The HVAC hydronic system is proportionally balanced per ASHRAE 90.1 energy standards. The proportional balance, when properly completed, will result in all the extra pump …
Hydronic Pump Energy Savings and Proportional Balancing Technique
ASHRAE Energy Standard 90.1 indicates the hydronic system shall have proportional balance and the pump over-heading shall be removed through speed reduction or impeller trimming. …
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 …
Balancing HVAC Hydronic Systems Part 3: Flow Measurement Valves
The flow balance of a hydronic system is a critical component in the commissioning of an HVAC hydronic system. The common balance and flow measurement …
Balancing HVAC Hydronic Systems Part 2: Control Valves vs. Balance Valves
There are some engineers who challenge the use of balancing valves at all in hydronic systems. If the control valve throttles the flow to satisfy …
Balancing HVAC Hydronic Systems Part 1: Flow Tolerance
The flow tolerance of a hydronic system is a critical component in the commissioning of an HVAC hydronic system. Should the balance report match the …