Jack Rise's guest appearances

Jack Rise

HVAC School - For Techs, By Techs

Kevin Hart

Bill Johnson

Ruth King

Chris Stephens

Dan Holohan

John Ellis

Bill Spohn

Andy Holt

Jerry Eavenson

Nate Adams

David Richardson

Jim Bergmann

Jim Loring

Jamie Kitchen

Corbett Lunsford

OwlTail

In today's podcast episode, we talk with system and duct design educator Jack Rise about ACCA Manual J load calculation and Manual S system selection. Many people know about Manual J, but relatively few techs follow it properly. When people attempt to do Manual J calculations, many of them go wrong when they overestimate the difficulty of the equations in Manual J. However, many of these techs do better when they can use software like Wrightsoft to help with their load calculations. The best way to approach load calculations is to develop confidence in software programs and field experience (sizing equipment and sealing ductwork); you are more likely to make mistakes if you put all of your confidence in one or the other. Some techs also don't take the time to measure buildings properly if they are either over-reliant on technology or too confident in their field skills. Manual S is all about equipment selection after the load calculation. However, much of the manual is not useful for fieldwork. The rules are also not as regionally thoughtful as they could be, especially regarding furnace sizing and the consequential heat loss. Manual S is only useful if you perform a Manual J calculation first and use that result as a guide. Rise does not believe that Manual S is bad, but he thinks it gives installers way too much leeway on sizing as it stands. Jack and Bryan also discuss:  Wrightsoft Manual J practices in different types of buildings Envelope leakage in retrofit applications Most important chapters of Manual S Accounting for sensible and latent heat load New ventilation requirements Odors, cooking, and building design Increasing airtightness in building construction Encapsulated attics Learn more about ACCA standards and codes at acca.org. Learn more about Wrightsoft HERE. If you have an iPhone, subscribe to the podcast  HERE, and if you have an Android phone, subscribe HERE.

In today's podcast episode, we talk with system and duct design educator Jack Rise about ACCA Manual J load calculation and Manual S system selection. Many people know about Manual J, but relatively few techs follow it properly. When people attempt to do Manual J calculations, many of them go wrong when they overestimate the difficulty of the equations in Manual J. However, many of these techs do better when they can use software like Wrightsoft to help with their load calculations. The best way to approach load calculations is to develop confidence in software programs and field experience (sizing equipment and sealing ductwork); you are more likely to make mistakes if you put all of your confidence in one or the other. Some techs also don't take the time to measure buildings properly if they are either over-reliant on technology or too confident in their field skills. Manual S is all about equipment selection after the load calculation. However, much of the manual is not useful for fieldwork. The rules are also not as regionally thoughtful as they could be, especially regarding furnace sizing and the consequential heat loss. Manual S is only useful if you perform a Manual J calculation first and use that result as a guide. Rise does not believe that Manual S is bad, but he thinks it gives installers way too much leeway on sizing as it stands. Jack and Bryan also discuss: <ul> <li>Wrightsoft</li> <li>Manual J practices in different types of buildings</li> <li>Envelope leakage in retrofit applications</li> <li>Most important chapters of Manual S</li> <li>Accounting for sensible and latent heat load</li> <li>New ventilation requirements</li> <li>Odors, cooking, and building design</li> <li>Increasing airtightness in building construction</li> <li>Encapsulated attics</li> </ul>Learn more about ACCA standards and codes at <a href="https://www.acca.org/home" rel="nofollow" target="_blank">acca.org</a>. Learn more about Wrightsoft <a href="https://www.wrightsoft.com/" rel="nofollow" target="_blank">HERE</a>. If you have an iPhone, subscribe to the podcast <a href="https://itunes.apple.com/us/podcast/hvac-school-for-techs-by-techs/id1155660740?mt=2" rel="nofollow" target="_blank"> HERE</a>, and if you have an Android phone, subscribe <a href="http://www.stitcher.com/podcast/bryan-orr-3/hvac-school" rel="nofollow" target="_blank">HERE</a>.

Intro to Manual J & S w/ Jack Rise

Jack Rise returns to the podcast to share some duct design facts with us and talk about his Manual D book on the ACCA website. Before we can even start thinking about duct design, we need to think about the total effective length; even before that, we also need to think about finding the critical path. The critical path is the path with the greatest resistance to airflow (from the return to supply); the fittings in the critical path contribute to the duct's total effective length. Flex duct is a controversial and somewhat complicated building material. It's common in Florida, but Jack doesn't use it in his duct designs; he can't depend on others to install it properly. Very few people tend to install flex ducts as tightly as they probably should. Noise is a problem for ducts, and takeoffs on the plenum are a significant contributor to noise issues. Instead, Jack suggests having a takeoff from the collar that goes straight into the appropriately sized duct for the desired airflow. (It's also worth noting that noise is subjective and is difficult to measure.) It's also unwise to position two takeoffs directly across from each other, as noise travels across those. The rise of indoor air quality (IAQ) products also requires us to look at duct design facts. Filtration improves IAQ but increases static pressure and can impede airflow. We need to be able to plan for IAQ products when we design ductwork. Jack and Bryan also discuss:  Selecting the equipment location and position Balancing damper placement and leakage Radial systems and symmetry Plenum sizing Why panning is not great (and illegal) Why bay jumping is a bad idea Duct design vs. truss positioning Airflow in the occupied zone    Check out Jack's book, Understanding Manual D,  HERE. If you have an iPhone, subscribe to the podcast  HERE, and if you have an Android phone, subscribe  HERE.

Jack Rise returns to the podcast to share some duct design facts with us and talk about his Manual D book on the ACCA website. Before we can even start thinking about duct design, we need to think about the total effective length; even before that, we also need to think about finding the critical path. The critical path is the path with the greatest resistance to airflow (from the return to supply); the fittings in the critical path contribute to the duct's total effective length. Flex duct is a controversial and somewhat complicated building material. It's common in Florida, but Jack doesn't use it in his duct designs; he can't depend on others to install it properly. Very few people tend to install flex ducts as tightly as they probably should. Noise is a problem for ducts, and takeoffs on the plenum are a significant contributor to noise issues. Instead, Jack suggests having a takeoff from the collar that goes straight into the appropriately sized duct for the desired airflow. (It's also worth noting that noise is subjective and is difficult to measure.) It's also unwise to position two takeoffs directly across from each other, as noise travels across those. The rise of indoor air quality (IAQ) products also requires us to look at duct design facts. Filtration improves IAQ but increases static pressure and can impede airflow. We need to be able to plan for IAQ products when we design ductwork. Jack and Bryan also discuss: <ul> <li>Selecting the equipment location and position</li> <li>Balancing damper placement and leakage</li> <li>Radial systems and symmetry</li> <li>Plenum sizing</li> <li>Why panning is not great (and illegal)</li> <li>Why bay jumping is a bad idea</li> <li>Duct design vs. truss positioning</li> <li>Airflow in the occupied zone</li> </ul> Check out Jack's book, Understanding Manual D, <a href="https://www.amazon.com/Understanding-Manual-D%C2%AE-Residential-Systems/dp/189276542X" rel="nofollow" target="_blank"> HERE</a>. If you have an iPhone, subscribe to the podcast <a href="https://itunes.apple.com/us/podcast/hvac-school-for-techs-by-techs/id1155660740?mt=2" rel="nofollow" target="_blank"> HERE</a>, and if you have an Android phone, subscribe <a href="http://www.stitcher.com/podcast/bryan-orr-3/hvac-school" rel="nofollow" target="_blank"> HERE</a>.

Duct Design Facts w/ Jack Rise

In this episode, Jack Rise talks about duct design regarding ACCA manual D, friction rate, face velocity, duct velocity, and what is ACTUALLY wrong with flex duct. Manual D causes a lot of confusion for technicians, and most techs have a limited understanding of it anyway. When determining a blower wheel for commercial ductwork, Jack Rise calculates pressure drops for all of his elbows in the ductwork and makes his decision based on those calculations. Residential HVAC is a bit trickier, and that's where Manual D calculations come in. Luckily, many software nowadays, including Wrightsoft, can calculate loads very precisely and help you with duct sizing. Just as with heat and pressure, there must be a velocity differential if you want air to move. If you need to move more BTUs of heat, then you need to move more CFM of air. Air also tends to take the path of least resistance. Trunk and branch design velocities must be different if you want any control over where the air goes. Trunk duct velocity typically stays between 700-900 CFM, but branch velocity can change quite a bit when you change the locations of the registers and grilles. Branch velocity tends to be 400-600 CFM. Good face velocity can be achieved by choosing the correct register and putting it in an ideal location. Flex duct is not a bad material, but it is controversial due to its reputation for being poorly handled. Manual D has an appendix on compression and sag, and techs who consult it will design a much better duct. Jack also discusses:  Available static Choosing a blower and factoring friction rate Oversized ducts Compression, sag, and bends in flex duct You can find the book at http://www.acca.org/store If you have an iPhone, subscribe to the podcast HERE, and if you have an Android phone, subscribe HERE.

In this episode, Jack Rise talks about duct design regarding ACCA manual D, friction rate, face velocity, duct velocity, and what is ACTUALLY wrong with flex duct. Manual D causes a lot of confusion for technicians, and most techs have a limited understanding of it anyway. When determining a blower wheel for commercial ductwork, Jack Rise calculates pressure drops for all of his elbows in the ductwork and makes his decision based on those calculations. Residential HVAC is a bit trickier, and that's where Manual D calculations come in. Luckily, many software nowadays, including Wrightsoft, can calculate loads very precisely and help you with duct sizing. Just as with heat and pressure, there must be a velocity differential if you want air to move. If you need to move more BTUs of heat, then you need to move more CFM of air. Air also tends to take the path of least resistance. Trunk and branch design velocities must be different if you want any control over where the air goes. Trunk duct velocity typically stays between 700-900 CFM, but branch velocity can change quite a bit when you change the locations of the registers and grilles. Branch velocity tends to be 400-600 CFM. Good face velocity can be achieved by choosing the correct register and putting it in an ideal location. Flex duct is not a bad material, but it is controversial due to its reputation for being poorly handled. Manual D has an appendix on compression and sag, and techs who consult it will design a much better duct. Jack also discusses: <ul> <li>Available static</li> <li>Choosing a blower and factoring friction rate</li> <li>Oversized ducts</li> <li>Compression, sag, and bends in flex duct</li> </ul>You can find the book at <a href="http://www.acca.org/store" rel="nofollow" target="_blank">http://www.acca.org/store</a> If you have an iPhone, subscribe to the podcast <a href="https://itunes.apple.com/us/podcast/hvac-school-for-techs-by-techs/id1155660740?mt=2" rel="nofollow" target="_blank">HERE</a>, and if you have an Android phone, subscribe <a href="http://www.stitcher.com/podcast/bryan-orr-3/hvac-school" rel="nofollow" target="_blank">HERE</a>.