Category Archives: Operations and Maintenance

These posts deal with O&M topics like maintenance and inspection techniques, maintenance costs, etc.

A New Application for Plot Digitizer (Plus a Quick Look at Hydraulic Variable Speed Drives and Chiller Free Cooling Cycles)

Those of you who know me know I am quite enamored with a little freeware application called Plot Digitizer.  If you are unfamiliar with it, the application allows to to create CSV (Comma Separated Value) files from the lines in … Continue reading

Posted in Boilers, Hot Water Systems, and Steam Systems, Chillers and Chilled Water Systems, Data Logging, Excel Techniques, HVAC Calculations, Motors, Operations and Maintenance | Leave a comment

Cooling Tower Flow Distribution and Variable Flow in Condenser Water Systems

One of my current obsessions is how subtle details regarding how you pipe a cooling tower can make a huge difference in how the flow is distributed.  I’ve been interested in that for a long time actually as the result … Continue reading

Posted in Condenser Water Systems, HVAC Fundamentals, Operations and Maintenance, Retrocommissioning Findings | Leave a comment

The Persistence of the Benefits of Commissioning (Plus a Few Pictures of Legacy Instruments)

As you probably have noticed if you follow the blog, I love finding old instruments in my travels. I have even been lucky enough to save a few of them from the dumpster, like this resonant frequency-based tachometer …   … Continue reading

Posted in Controls, Mentoring and Teaching, Operations and Maintenance, Pneumatic Controls, Retrocommissioning Findings | Leave a comment

Resources for the Resourceful – Utility Analysis Spreadsheet Tool

Authors Note: Since the point in time when I published this post, some of the links have expired. So, I have gone through it and renewed them and also made a few edits. Linking to the Weather Data Depot in … Continue reading

Posted in Excel Techniques, HVAC Calculations, Operations and Maintenance, Resource List and other Resources, Retrocommissioning Findings | Leave a comment

Pneumatic Controls Resources

Author’s Note: I originally published this post on March 3, 2013.  At that time, all of the resources I mention below were loaded up in “the cloud” on a Google Drive.  Since that time, I have created the commissioning resources … Continue reading

Posted in Operations and Maintenance, Pneumatic Controls, Resource List and other Resources, Retrocommissioning Findings | Leave a comment

Condenser Water Systems, Air Entrainment, and Pump Cavitation

This post is the result of a discussion I was having as the result of a comment made on a previous post about commissioning a condenser water system.  The initial question was to ask if the solution I had suggested … Continue reading

Posted in Chillers and Chilled Water Systems, Operations and Maintenance, Retrocommissioning Findings, System Diagrams | Tagged , , | Leave a comment

Control System Fundamentals

This post evolved to support a string of posts I will start next to support an exercise in one of the classes I am involved with at the Pacific Energy Center.  In those posts, we will look at how you … Continue reading

Posted in Controls, HVAC Fundamentals, Operations and Maintenance, Pneumatic Controls | 2 Comments