## Centrifugal Pumps: Determining Flow Rate Using Amp Readings

Norm Hall

We understand that the best way to determine the flow rate of an operating pump is the proper readout of gauges attached to the pump …

## Create a New Variable Speed Pump Control Curve after Hydronic Balancing

Norm Hall

This week, the R. L. Deppmann Monday Morning Minutes will explain how to show multiple speeds on a pump curve and how to determine what …

## Hydronic Pump Balance using the Variable Speed Drive (VFD) with No Balance Valve on Pump

Norm Hall

When there is no hydronic pump discharge balance valve, the variable frequency drive (VFD) is an important part of the balance procedure. How does the …

## Hydronic Pump Balance using the Variable Speed Drive (VFD) with Assistance from a Triple Duty Valve

Norm Hall

Most centrifugal pumps in heating and cooling systems have some oversizing in the head calculation. Once the HVAC hydronic system is proportionally balanced per ASHRAE …

## Open Cooling Tower System Pumps – Balancing the Pump Using a Drive

Norm Hall

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

Norm Hall

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

Norm Hall

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. …

## Process System Pump Selection: Controls to Reduce Maintenance Time

Norm Hall

In the last R. L. Deppmann Monday Morning Minutes I defined the difference between flat curves and steep curves in a hydronic pump selection. I …

## HVAC Hydronic Pumps – Should I Trim the Impeller or Trim with Speed? (Part 2 of 2)

Norm Hall

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)

Norm Hall

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 …