Category Archives: HVAC Fundamentals

Useful fundamental principles and concepts that apply to HVAC and Building Science

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

Site versus Source Energy

Author’s Note:  I originally posted this in September of 2007 and used a report I had found at that time to develop some of the source energy factors I used in my illustration.   Since then, I have found a number … Continue reading

Posted in HVAC Calculations, HVAC Fundamentals, Resource List and other Resources | 2 Comments

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

Build Your Own Psych Chart – Creating the Data for the Saturation Curve and a Bit About VLOOKUP

So here I am, over a year later after starting this string, getting back to it.  All I can say is life happens and sometimes, because of that, you find that what you set out to do takes a bit … Continue reading

Posted in Excel Techniques, HVAC Calculations, HVAC Fundamentals, Psychrometrics | Leave a comment

A Free Electronic Psych Chart and How to Use It to Plot Basic HVAC Processes

Ryan Stroupe of the Pacific Energy Center recently worked out a deal that allows him to provide a free limited capability version of Hands Down Software’s electronic psych chart.  You can get a copy at this link and a overview … Continue reading

Posted in Air Handling Systems, Economizers, Excel Techniques, HVAC Calculations, HVAC Fundamentals, Psychrometrics, Resource List and other Resources, Weather and Climate Interactions with Buildings and Systems | 1 Comment

Retrocommissioning Findings: Reducing Boiler Purge Cycle Losses

Greetings after another break in the action in terms of my posting rate.  As those of you who follow this blog know, sometimes, I get pretty busy and since writing this is not exactly my “day job’, my posting rate … Continue reading

Posted in Data Logging, Excel Techniques, HVAC Calculations, HVAC Fundamentals, Operations and Maintenance, Retrocommissioning Findings | Leave a comment

Unit Conversion Constants; Why Consistent Engineering Units are Important and Where the 3,960 in the Pump Power Equation Comes From

I recently received a question from one of the students in a class I am involved with about the Pump Power equation.  They were working with the equation in the form shown below, which is from the slide deck I … Continue reading

Posted in HVAC Calculations, HVAC Fundamentals | Leave a comment