How to Size Dehums w/ Tim De Stasio

In this episode of the HVAC School podcast, host Bryan Orr interviews Tim De Stasio, an experienced HVAC practitioner and consultant. Tim shares his journey in the HVAC industry, from his early days in vocational school to running his own contracting business for 12 years. He now focuses on consulting, design, and contractor training, allowing him to pursue his passion for HVAC while sharing his knowledge with others.

The conversation delves deep into the world of dehumidifiers, exploring their importance in modern HVAC systems, especially in humid climates. Tim emphasizes the need for supplementary dehumidification in many homes, particularly during part-load conditions when air conditioning systems may not effectively control humidity. He explains the process of selecting and sizing dehumidifiers, stressing the importance of considering factors such as peak latent load conditions, actual dehumidifier performance under real-world conditions, and static pressure effects on output capacity.

The discussion also covers the critical role of proper envelope sealing and ductwork in managing humidity. Tim advocates for addressing these issues before installing a dehumidifier, highlighting the importance of blower door testing and fixing any leaks. The podcast concludes with insights on dehumidifier control strategies, the limitations of ERVs in humidity control, and the potential risks associated with uncontrolled outdoor air introduction into HVAC systems.

Key topics covered in the podcast:

Tim De Stasio's background and transition to HVAC consulting and training

The importance of supplementary dehumidification in various climates

Selecting and sizing dehumidifiers based on peak latent load and real-world performance

The impact of static pressure on dehumidifier output capacity

The necessity of addressing envelope and ductwork issues before installing dehumidifiers

Strategies for controlling dehumidifiers in conjunction with AC systems

Myths about dehumidification, including misconceptions about variable speed equipment and ERVs

The potential risks of uncontrolled outdoor air introduction and the importance of proper ventilation strategies

Resources for learning more about dehumidification and HVAC best practices

Tim DeStasio's contact information for those seeking advice or design services

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

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.

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##hvacschool #dehumidification #HomeComfort #HumidityControl #hvac #HVACConsulting #HVACTips #TimDeStasioHVAC #TradesEducation

Author:

Bryan Orr

Company: HVAC School

Position: Founder

Tim De Stasio

Company: Comfort Science Solutions LLC

Position: Owner and President

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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.

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.