#VRV

Tech Tips:

This tech tip recaps the livestream by the same name, featuring HVAC School contributors Matt Bruner and Adam Mufich, as well as special guest Steve Cook from Hisense. You can watch that livestream on our YouTube channel HERE. We also owe special thanks to Roman Baugh, who added some extra information on the topic. Communicating […]

VRV Operation

This tech tip is written by experienced tech and VRF / VRV specialist Ryan Findley. Thanks, Ryan! (Note: Ryan refers to VRV rather than VRF because he specializes in Daikin, and these articles are written from a Daikin VRV perspective. Ryan has also written an article about VRV basics and some VRV installation tips.) This […]

VRV/VRF Installation Tips

This tech tip was written by experienced tech and VRF/VRV specialist Ryan Findley. Thanks, Ryan! (Note: Ryan refers to VRV rather than VRF because he specializes in Daikin, and these articles are written from a Daikin VRV perspective. He also wrote a great introductory guide to VRV systems, which you can find here.) In this […]

VRV Basics

This tech tip was written by experienced tech and VRV specialist Ryan Findley. Thanks, Ryan. This is a quick overview, not a substitute for taking proper manufacturer training. This tech tip is geared towards the mechanic who is fairly new to VRV systems. As with anything, before we harness the ability to install or […]

Introduction to VRV/F Systems with Roman Baugh

So You Want to Service VRF?

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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 today’s podcast, Bryan talks with legendary Hydronics author and trainer Dan Holohan about the history of steam heating and some practical applications of old ideas. Recently, Dan has been working on more novels, having published two of them over the past few months.

Steam heating is a “lost art” nowadays; it has become increasingly uncommon and has been disappearing since the Vietnam War. Many people who understood steam heating either retired or died after the Vietnam War. Many elements of steam heating are difficult to understand or surprising. (For example, steam pressure has a surprising relationship with velocity: low-pressure steam moves through piping much more quickly than high-pressure steam.) So, Dan Holohan is on a mission to revive that knowledge and teach the newer generations about the lost art.

There are many older steam heating systems still operating today, especially in the older large buildings in New York. Dan learned a lot about steam heating when working on these old systems and optimizing them. Most of the time, he optimized those systems by removing unnecessary accessories, not by adding components like steam traps.

Many old boilers used coal as a heat source. Nowadays, many old boilers have been fitted with conversion oil burners with thermostats, but they are still piped for coal. Some systems now have multiple risers or massive vents on the main riser to prevent the thermostats from getting too hot too early and satisfying the thermostat too early. We call that master venting, which reduces pressure and allows steam to move very quickly and efficiently.

Dan also discusses:

The 2-PSI standard
Transportation metaphors for BTUs in steam
Harmful renovations for old boilers
Replacement vs. restoration mindsets
Gaps in steam boiler education
Monopolizing the market if you HAVE the education
Boiler piping and venting
Two-pipe vs one-pipe steam

Find out more about Dan and hydronic heating at HeatingHelp.com.

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

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