Category Archives: Economizers

These posts discuss various topics related to HVAC air and water side economizers.

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 | Leave a comment

Economizer Analysis via Scatter Plots–Linking Excel Chart Labels to Data in Cells

As you may recall, this fall, I started a string of posts on using scatter plots to assess building performance.  The 8th post in the series was going to use the technique to assess and economizer by comparing what a … Continue reading

Posted in Economizers, Excel Techniques | 2 Comments

Economizers–The Physics of Linkage Systems

In the post before the previous, I was discussing an economizer performance problem in a facility we worked with as a class in Monterey California.  One of the problems was related to the mechanics of motion in the linkage system … Continue reading

Posted in Air Handling Systems, Controls, Economizers, Pneumatic Controls | Leave a comment

Economizers–The Physics of a Mixed Air Plenum

I’ve been working on a post that shows how a scatter plot technique can be used to assess the performance of an HVAC airside economizer.  It’s based on comparing a plot of outdoor air temperature vs. mixed air temperature for … Continue reading

Posted in Air Handling Systems, Controls, Economizers, HVAC Calculations, HVAC Fundamentals, Psychrometrics | Leave a comment

Working with the Honeywell W7212 Economizer Controller; Nuances of the Economizer Control Process, Part 2 –Economizer Basics

In this post, I am going to define a few terms related to economizer processes so we are all “on the same page” for what will follow as I move forward with the W7212 discussion. I am writing this at … Continue reading

Posted in Controls, Economizers, HVAC Fundamentals | Leave a comment

Working with the Honeywell W7212 Economizer Controller; Nuances of the Economizer Control Process, Part 1 –Background

  This post is the second in a series I started a while back  on the Honeywell W7212 controller.  I recently did a lab session that was built around the controller and having had questions from several of the attendees … Continue reading

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Retrocommissioning Findings: Economizer Mixed Air Plenum Stratification–Overview

Happy New Year! I hope everyone had a nice holiday and now are getting back into the swing of things.  Kathy and I had a great holiday and are just finishing putting away the Christmas decorations, which always seems to … Continue reading

Posted in Air Handling Systems, Economizers, Retrocommissioning Findings, Weather and Climate Interactions with Buildings and Systems | 2 Comments