#combustion analyzer

Tech Tips:

While gauge manifolds and manometers may only have one main function, some tools take several different measurements and will have more expansive specs. The combustion analyzer is one such example—combustion has so many elements, and we need something that can analyze the concentrations of several different substances as well as temperature. As such, a combustion […]

How To Do a Heat Maintenance That Actually Matters

I know I’m not the only one who has sometimes felt a little bad doing heat maintenance. I remember many a day when my lead technician and I (as an apprentice) would crawl into an attic, clean the flame sensor, and then play FarmVille on our phones for 15 minutes before crawling down, giving the […]

Practical Uses of Combustion Analysis

This tech tip reviews the live stream by the same name aired on November 1st, 2023. You can watch the full live stream HERE. We want to give special thanks to the guests: Jim Bergmann, Jim Davis, Tony Gonzalez, Louise Kellar, Bill Spohn, and Tyler Nelson! Gas furnaces (or any combustion equipment) create a controlled […]

Leading With Intent At The Sauermann Booth

INFICON – Innovative & Disruptive: Here’s What’s New at the INFICON Booth

Chris Kryvosheieva

Check out our most recent video

How to Evacuate an AC system, Full Vacuum Procedure

Our latest Podcast

HVAC School – For Techs, By Techs

Real training for HVAC ( Heating, Ventilation, Air Conditioning and Refrigeration) Technicians. Including recorded tech training, interviews, diagnostics and general conversations about the trade.

In this short episode, Bryan clears up the confusion behind pumping vs. compression.

Pumping is usually associated with liquid. Liquid, like vapor, is a fluid, but it’s a lot denser and is essentially incompressible because the molecules are close together. Liquid volume varies based on temperature and density, but we can’t squish the molecules together. That’s why compressors with very little axial and radial compliance fail when flooded; they can’t compress the liquid. A circulator pump in a hydronic system is an example of a pump that pushes liquid along, but the pressure difference across the pump is minimal compared to that of a compressor; the same is true of liquid vs. vapor CO2.

However, vapor molecules are far apart and can be squished together to take up a smaller volume. That’s why vapor can go through compressors, which take a fluid of one volume and apply pressure to shrink it to a smaller volume, raising the temperature in the process. Pneumatics, as opposed to hydraulics, utilize compression to move vapor around in a circuit. Recovery machines need to be able to compress vapor refrigerant and pump liquid into the recovery tank.

Compressors and pumps can either be positive displacement or non-positive displacement systems. A positive displacement system creates a trap and forces a fixed amount of fluid through a system, like a scroll compressor or a circulator pump. Refrigerant volumes may vary because vapor density varies with temperature and pressure (the volume flow is the same, but the mass flow varies). A condensing fan motor, on the other hand, is dynamic and varies the volume of air it moves in response to pressure, as the mechanism relies on velocity and kinetic energy to move air.

Have a question that you want us to answer on the podcast? Submit your questions at https://www.speakpipe.com/hvacschool.

Purchase your tickets or learn more about the 6th Annual HVACR Training Symposium at https://hvacrschool.com/symposium. Subscribe to our podcast on your iPhone or Android. Subscribe to our YouTube channel. Check out our handy calculators here or on the HVAC School Mobile App for Apple and Android.