CFD simulation and analysis on the impact window placement has on natural ventilation by Jacob Gabrielse

ARC 688 - Directed Research

CFD simulation and analysis on the impact window placement has on natural ventilation in the residential home By Jacob Patterson & Nicholas Ostafew Abstract Advances in building technologies have given us more control over a building’s envelope and the systems within it. These changes in the design and construction of the building envelope often leave out consideration for good natural ventilation because the building envelope becomes more tightly sealed, thus less breathable. In contrast, the utilization of well designed natural ventilation can improve the overall health of the building and its occupants. Natural ventilation can also help a building to become more energy efficient by extending the period of time when mechanical systems are not needed and thermal comfort can be achieved naturally. In order to create better efficiency of natural ventilation and its capability to extend natural thermal comfort, we are studying the impact of window placement in a residential model using a computational fluid dynamics program, Autodesk CFD. This program will allow us to track and analyze air currents as they enter and leave a residence in a controlled environment. The series of models and data gathered through CFD software will allow for analysis of the air movement within rooms at a more cost-efficient and detailed level than through the use of physical methods. The initial findings of this study will be analyzed through the lense of natural ventilation history, as well as what is considered good natural ventilation by ASHRAE and and other scholars definitions. The choice of the cross ventilation method we have chosen to be a part of our model will also be assessed accordingly. Keywords - CFD; natural ventilation; fluid dynamics; cross ventilation; residential; air flow

Introduction Ventilation is used to moderate the thermal comfort of a space people who occupy it through velocity by displacement of hot air, or through evaporative cooling which removes the latent heat through waters change of state. Ventilation also serves to keep a certain air exchange rate allowing for a healthy composition of air quality. The lack of air quality in indoor spaces has been known to contribute to the spreading of infectious airborne diseases, microorganism growth in humid climates, allergies, cancer due to lack of smoke evacuation, skin irritation, nausea, and sick building syndrome. Sick building syndrome (SBS) is the culmination of acute health conditions that can be caused by poor ventilation within a building. Indoor air quality is an integral component to a healthy lifestyle. Lewis W. Leeds, a ventilation and heating engineer, once said, “Man’s own breath is his greatest enemy.” This statement was in response to toxic American east coast cities in the nineteenth century which had many deaths due to poor air quality (Battaglia & Passe 2015) Ventilation is a major factor in the consideration of a building’s energy efficiency due to the energy requirements to maintain the interior climate through heating and cooling. A study done in 2009 revealed that residential homes used 39 percent of the total energy consumption to condition indoor space. This signifies the potential for significant improvement in ventilation based energy use, especially in climates that require larger heating or cooling loads. Natural ventilation can provide or improve indoor thermal comfort when interior conditions are too hot but natural air movement is available and manageable to condition the interior space without the use of mechanical systems. In order for natural ventilation to work efficiently, air must be allowed to travel within a space freely and be designed in such a way that takes advantage of the physics of air movement. (Battaglia & Passe 2015)

A Brief History of Ventilation Poor ventilation has caused death, disease and widespread health problems, as something we still research today it is necessary to review the history of ventilation. Reflection on ventilation history gives an awareness to the challenges of passive ventilation and

maintaining thermal comfort, as mechanical systems were not always available to sustain these attributes in a building. The use of fires for heating and cooking within homes was one of the first drivers to improve ventilation. A result of bringing fires in homes meant a need for steady airflow to provide oxygen for the fire, as well as to evacuate the smoke. In ancient Egyptian cultures, wall paintings depict breathing distress and document a requirement for ventilation in order to keep dust levels down. The Egyptians, in a similar way to evacuating smoke from a fire, needed to keep air moving while filtering out dust. Further advances show Romans using fires in interior spaces to heat hollow tiles and the undersides of floors while evacuating the smoke through chimneys. Romans began to develop a window to floor area ratio to help solve some of the problems of too much or too little ventilation while maintaining light quality. They developed oiled parchment to cover openings allowing for air infiltration while creating a semi-sealed envelope, similar to modern practices of conventional window screens. The creation of sheet glass to replace parchment for windows was first widely used during the 13th century in medieval Europe. In the 16th century, King Charles the First became aware of disease spread due to poor ventilation, and declared that windows should be taller than they are wide and ceilings must be at least three meters tall. Almost all other articulations of windows and ventilation from this point forward were the result of society’s reaction to bad health conditions or death, and it was not until the late 1900’s that a more full analysis on air quality was done. Modern improvements to windows improved the thermal properties of glass, style of operation as well as widespread manufacturing of windows. (Janssen 1999). Klaus, a Cornish mining engineer published by the scholar Thomas Tregold, studied respiration needs. “He calculated from the breathing rate that a subject needed 800 in.3 /min. of unvitiated air to purge the CO2 from his lungs.” (Klauss 1970). This later took into account the amount of CO2 and moisture a person emits and was translated to a range of recommended volumetric flow rates, such as cubic feet per minute (CFM), of fresh air per building occupant. In 1910, the Chicago Health Department, with help from the American Society of Heating and Ventilating Engineers (ASHVE) laboratory, created a report that concluded carbon dioxide in the air was not the primary concern for health, but rather keeping relative humidity controlled was the most important objective of ventilation. ASHVE also confirmed Klaus’s study of a requirement of at least 30 CFM of outside air for each occupant to be in a healthy environment. Similar studies surrounding schools were done in New York and concluded that, “Window-ventilated rooms at a temperature from 59°F to 67°F (15°C to 19°C) had the lowest

rate of respiratory illness.” A result of these studies lead to ASHVE developing a minimum standard for the heating and ventilation of buildings in 1925. This standard eventually led to what is now known as ASHRAE, or American Society of Heating, Refrigeration, and Air Conditioning Engineers. In 1973, ASHRAE developed a Standards for Natural and Mechanical Ventilation, which is the foundational document from which most U.S.state codes regarding ventilation are now derived.(Janssen 1999) The history of ventilation brings to light the necessity for good ventilation in interior spaces; but not necessarily what particular methods are best, to have been deemed effective or efficient, to ventilate space and offer thermal comfort.

Good Natural Ventilation Good natural ventilation can be assessed as creating a thermally comfortable environment, with even air distribution that maintains a certain average velocity without extreme lows or highs. This even distribution and attention to thermal comfort also keeps in mind health as there are minimum standards for air exchanges within a space. ASHRAE puts residential outdoor required air rate minimum at 5 cfm per person and 7.5-10 for commercial/public spaces. (Battaglia & Passe 2015) As natural ventilation utilizes only outdoor air for ventilation in this study, the air rates will be far greater than these minimums. Baruch Givoni a researcher for 30 years on passive and low energy cooling of buildings, notes there are two types of ventilative cooling:comfort ventilation and nocturnal ventilative cooling. Comfort ventilation takes place during the day to provide air movement to occupants throughout the day, while nocturnal ventilation is the opening of the building envelope during the evening and night in order to cool a buildings mass to allow for a cooler indoor temperature the next day. Our study will keep in mind both but be primarily focused on efficiency and effectiveness,with which comfort ventilation is more directly associated. (Givoni 1994) The ASHRAE standard for the highest indoor airspeed, to maintain acceptable comfort levels, is 1.8 miles per hour. This guide neglects to take into account more extreme climates and humid conditions where higher air movement speeds are morewidely accepted. Natural ventilation is more applicable in certain climates over others and is best taken advantage of when outdoor air temperature is colder than indoor temperature. Although this is the best case scenario there are many other factors involved, including shaded areas and evaporative cooling which can assist and extend the acceptable temperature and humidity levels in which natural

ventilation may be utilized. Baruch Givonisuggests that allowing for indoor wind speeds from a higher range of 3.3 to 4.5 miles per hour with a maximum air temperature of 89.6 degrees fahrenheit fall into the wider thermal comfort range in Image 1 (pg.18), where natural ventilation is acceptable. This psychrometric chart gives a good basis for when natural ventilation is ideal and can be designed for, as well as where a change in ventilation methods should take place at the limits of the thermal comfort zones. “Current design practices for air distribution in operating rooms rely heavily on research by Memarzadeh and Manning. Early research in the late 1960s by Kenneth Goddard started the industry dialog about total air changes needed in operating rooms to minimize postoperative infection rates.” The figure on

the

right

shows the relationship

between bacteria amount and air change rates. Although this air is filtered, there should be a lower equivalent for fresh outdoor air. This is a case for rethinking ASHRAE standards for interior air quality as several of our models meet hospital level exchange rates. (Barrick 2014) After analyzing what times of the year natural ventilation is viable according to Image 1 (pg.18), the next step is applying strategies to find the most effective way to ventilate the interior spaces. Strategies include: ●

Cross-ventilation, which will be the focused method in this study, directs air through a building by bringingair in on one side and expelling out the opposite side.

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Single-sided ventilation uses openings along a single side of a building, where the air is leaving the same penetrations it came in, which can be seen occuring in some of the smaller rooms in the model.

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Stack effect ventilation uses the physics of air including density, temperature and pressure to send air through the interior of a building and out through a vent at a particular rateThe wind above the vents also help in creating a negative pressure to draw the air out of the building.

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Solar Chimneys use the sun to heat the air in a chimney structure to draw out internal air through by a negative pressure created by the hot air rising out of the building.

These strategies can have a wide array of effectivenessOther factors that influence air movement within a space and determine a strategies effectiveness also must be considered. These factors include geometric configuration or shapeof the space, location of windows, type of windows, total area of opening, interior obstructions, wind direction, and screen detailing. One of the major results in the changing of these factors is the creation and changes to eddy currents that occur in the space. Eddies are a fluid current whose flow direction differs from that of the general flow, creating vortices. Eddies form when the airflow around an object reaches a high enough velocity to create a pocket of lower pressure behind the object, causing the current to be pulled into the pocket. An air current with many eddies is considered turbulent, however eddies can transfer much more energy and mix the air better than molecular diffusion in non-turbulent currents. This is because eddies are able to mix large volumes of air easily. As the velocity of the air current increases more eddies are generated, and as energy is transferred the eddies decrease in scal till they dissipate. Eddies are capable of producing sound, which can be a discomfort for residents. (Britannica 2006) In order to judge the interior conditions and the effectiveness of the ventilation, air speed at the opening, maximum airspeed within the space, average air speed in the space, and distribution of the air should be analyzed.(Givoni 1994) This study will keep in mind all these factors as we seek to find the impact and effect that window placement has on naturally ventilated spaces using the strategy of cross ventilation.

Experimental Model The model we chose for this study is a one-story ranch house with basement, oriented in an east-west bar. The modeling of our residential home was done in Autodesk Revit due to its ease of use and direct compatibility withAutodesk CFD. The plan is based off several three-bedroom, two-bath, home plans that utilize a central open shared space of the living room, dining room, and kitchen. The plan allowed for a focused study of the cross ventilation in the vaulted central space, while maintaining a global airflow throughout the home. Although not all furniture was modeled in the central space, the kitchen cabinets, countertops, and fridge were modeled in the kitchen to create some interference with the air as it moved through the space.

When converting the Revit model to the CFD software some of the detail of elements needed to be simplified as to not create an overly complex simulation model. This mainly consisted of the removal of door trim and initially window trim. During the simplification of the doors, it was decided to remodel all the doors, besides the front door and the door to the basement, to create a three-quarter inch gap between them and the floor, where a half inch gap is typically required by U.S. state codes.. This was done to help simulate potential air leakage between rooms while the doors are closed. After testing how to setup the model in the CFD software, we reassessed how to test the variety of window placement options, without needing to remodel the home between each simulation. The solution was to create testing areas that window openings could be placed in curtain wall systems with a one square-foot panel system. This allowed for flexibility in running multiple simulations from one building model by changing material properties of the panels between simulations to move window openings while maintaining a consistent total window square footage per test area. The Revit model was then brought in Autodesk CFD for the simulation setup. An external volume was added to create air around the home for the external wind force to flow through. Materials were applied to the model in the categories of fluid (air) and solid (wood, glass, glass wool insulation, stone and concrete). Although the breakdown of materials beyond fluid air and a solid material were not required for these tests, additional tests into thermal effects could be performed with more accurate material application. Once materials were selected, boundary conditions were added to the external volume. The external wind was set as a velocity of eight miles per hour, which is considered a gentle breeze and a three on the Beaufort Scale (NOAA 2016), along the southern face of the external volume. The wind flow from south to north was used to simulate a location that consists of mainly southern winds throughout the year, such as Nashville. The front of the residential house faces the gentle breeze so that the wind direction is perpendicular to the window openings. The remaining sides of the external volume were given boundary conditions of zero pressure to simulate an open-air condition without making an overly large external volume. The house did not require any boundary or initial conditions because the air was free to flow in and out of the windows within the open-air conditions established on the external air. The model was then meshed with the automatic meshing function. Meshing establishes the geometries that need to be solved in the simulation and at what level of detail they consist of. This is very similar to the meshing used in 3D printing software and .stl files. The scenario was then duplicated for the seven window placement tests studied and labeled Model

CC through Model SV. Material properties of the panels were adjusted in each model to reflect the window placement accessed in scenario. The solve settings used for all the scenarios were 100 iterations in the “Steady State” solution mode, with “Flow” and incompressible fluid physics enabled. Once the simulation was run, result planes and traces were set up in each model to analyze and compare the results of the scenarios. The planes show Velocity Magnitude in a transparent shading and Velocity Vectors on a grid size of 5-7.7, also shaded and scaled to reflect their Velocity Magnitude. These settings provided the best visuals for seeing both wind velocity as well as direction within the space. Image 2-3 (pg.19) (Note: The approximate location of the sections and plan slices taken from the model for graphic analysis and correspond with the labeled images, ex. CC vector plan low). Trace grids were set up at the central space’s rear windows and a larger grid size trace across the whole rear face. Traces show the path of the air that flows through the points created, therefore by putting them on the rear windows and setting them to only show “backwards” the traces can show where the air that leaves that window comes from. The traces are colored to show the velocity of the air along the path; however, thin line traces were used to keep them from getting over-cluttered in the model. Other tools used to assess the simulation results were “XY Plots” and “Bulk.” XY plots are created by picking points along a plane. The points chosen for each scenario run straight through the space from the center of the front window the plane runs through. These plots show the velocity of the air over the distance into the space. The “Bulk” tool calculates bulk-weighted results and was utilized to calculate the exchange rates through the rear windows based on a plane that runs through the rear wall. Due to cutting through the solid material as well as the windows, this tool automatically calculates each window separately. The basic setup of our model can be found on Autodesk’s website. (Learn n.d.)

Data and Analysis Double Hung Windows Even Spacing (Model CC):

Our first model, Model CC, is our control that uses window placements similar to typical double hung windows with even spacing of windows. All of the following models will have variations of window shape and placement that can be comparatively assessed to this control. Model CC has an upward flow of air movement that creates a major eddy, or rotating air current, in the vaulted space as seen in CC All Center Traces Section. (pg.21) The major eddy creates a stagnation of air at the center of the spiraling current. In addition to this major eddy, there are several minor eddies under the front double hung windows, as well as one between the kitchen island and kitchen cabinets. The velocity of the interior air significantly increases in velocity as it is forced from the interior space through the rear windows. The key components analyzed and compared between our models are the velocity of the air at one foot into the space, the point at which the velocity reaches the threshold of comfort (1.8 mph) and the threshold stagnation(0.5 mph). The stagnation threshold is a term used to refer to air that is significantly slowed in velocity,under 1 mph, and is being recycled at an unhealthy rate. The 1.8 miles per hour threshold of comfort is based on the ASHRAE limit; however, it is key to note that Givoni puts this threshold as high as 4.5 miles per hour. These values are pulled from each model’s Vector Section 2, except Model SV’s data which came from Vector Section 1. Model CC had a velocity of 3.4 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 5 feet, and threshold of stagnation occuring at approximately 16 feet. In Model CC, unlike Model SV, the small square openings bottleneck the airflow lowering the maximum entrance speed. The high air velocity streams of air at human height shows the model as an

uncomfortable solution to window placement. The air exchange rate of Model CC was 47.8 which is at the upper end in comparison with the other models. Base Wide Ribbon Window (Model BB)

In Model BB we focused the windows to be flush with the floor plane and as low as possible in the kitchen on the rear. The resultant path of the air is more controlled as the wind hits the exterior of the building it is pulled downward into the opening by the difference in pressure. The opening of this front widow as seen in the above elevation is much wider horizontally, allowing for less interruptions of the air entering the space. BB All Center Trace Section (pg.28) shows a concentrated air stream entering and flowing upwards into the space. Approximately two thirds of the air exits the building without circulating through the space, while a third lingering in a egg shaped pattern in the vaulted ceiling before being expelled from the space. This eddy draft is similar to those seen as the air travels and downdrafts after passing over the kitchen counter in BB Vector Plan High (pg.34). BB Vector Plan Low (pg.33) shows the additional eddies in a clockwise motion from the main stream of air. The higher cfm from the low windows in Model BB also causes a rise in velocity as the air is forced through the smaller rear window. Model BB had a velocity of 4.4 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 10 feet, and threshold of stagnation occuring at approximately 14 feet. The high entry velocity and depth required to reach the threshold of comfort, along with the low placement, makes sitting spaces uncomfortable for residents. The overall air exchange rate per hour is 38.5, which is 9 exchanges lower than Model CC. The comfort levels of a resident are only comprised at sitting heights, and would be effective for kitchens or rooms where there is less of a need to sit. The high velocity at low elevation is significantly blocked by low obstructions such as furniture and is the cause of the low amount of air exchanges.. In addition to the eddy effects in the main space the air seeks out further paths

of escape under doors in BB All Traces Plan (pg.34). This eddy effect favors the north east corner room in the plan as the velocity in plan is higher in the eastern window of the main volume. Base Front Windows & Top Rear Window (Model BT)

A variation of Model BB changes the rear set of windows to be at maximum wall height. Model BT has a high exchange rate of 47.6 per hour comparable to Model CC of 47.8. The air trapped in the vaulted space is more efficiently evacuated as the rear windows are placed higher and as seen in BT All Center Traces Section (pg.35) compared to BB All Center Traces Section (pg.28). The images do not have many distinguishable differences, however the eddy currents are less restricted by the kitchen counter. The position of the exit windows change the air exchange rate significantly from Model BB with roughly 9 additional air exchanges per hour or approximately 24 percent more exchanges. The lower restriction of the air as it exits the building may be seen in BT Vector Plan Mid (pg.40) as compared to BB Vector Plan Mid (pg.33). Model BT had a velocity of 4.4 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 9.5 feet, and threshold of stagnation occuring at approximately 14 feet. This model will be slightly less comfortable than Model BB because the bulk flow of air is passing diagonally through the sitting height of a person at 4 ft up to standing height. Overall the model is very comparable model to the original Model CC in data even though the air path is significantly altered. The airspeed after 9.5 feet is in the acceptable comfort range and with the highest exchange rate so far offers a strategy for shorting the amount of cooling days in residences that can stand a slightly higher wind speed.

Side Windows Front and Rear (Model SS)

The air in this model enters the space on either side through wide vertical slits. The SS All Center Traces Section (pg.41) has distinct similarities to BT All Center Traces Section (pg.35) and follows a similar path, but the primary eddy takes place higher in the volume of space as well is more horizontal in orientation. The rear of the building with four windows on the main space offers a better distribution of air volume to each opening. Air in this model as well as others follows the path of least resistance, but obstructions like exterior walls force the perpendicular air current through the openings creating new patterns. SS Vector Plan Mid (pg.48) shows a distinction in the eddy currents of the air and there is a distinct swirl back towards the entrance wall. Overall there is less of an upward draft as seen in Model BT as the windows cover a larger vertical section of the wall. The air exchange rate of 43.66 is not as high as Model BT due to the turbulence seen in plan. Model SS had a velocity of 4.1 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 8.5 feet, and threshold of stagnation occuring at approximately 15.3 feet. The entrance velocity is uncomfortable to the average person as you pass through the room, which is displayed in SS Vector Plan Mid (pg.48). Although Model BT and Model SS both have large eddy currents in section, this can be desirable as it helps to displace hot air that has risen to the vaulted portion of the room.

Centered Thin Ribbon Windows (Model SH)

Model SH is closest in placement to Model CC however the main space has two long horizontals rather than being broken up into double hung windows. Model SH had a velocity of 2.8 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 5 feet, and threshold of stagnation occuring at approximately 20 feet. The entrance velocity is is slightly lower than Model CC as compared in CC All Center Trace Section (pg.21) and SH All Center Traces Section (pg.50). The tendency of the air as it enters is to peel/curl away from the central mass of air and down towards the floor. The distinct eddies formed can be seen on the east and west of the primary space in SH Vector Plan Low. The eddies it forms however do not leave room for undisturbed areas of air like model CC does. The air exchange rate is comparable with the base model CC at 46.1 with minimal change to the positioning of the openings. The lack of resistance between windows allows for a better consistency of air velocity, and is overall closer to ASHRAE guidelines of comfort.

Top Ribbon Windows Front and Rear (Model TT)

In Model TT the air enters the space at a similar velocity to Modell BB, well above the comfortable velocity for air. Model TT had a velocity of 4.2 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 10 feet, and threshold of stagnation occuring at approximately 20 feet. A distinction of this model with all windows moved towards the top of the room is the large eddy current that takes place under the entrance window. Similar to the eddies in SH All Center Traces Plan (pg.50) the air breaks away from the main current of air in two directions. The currents of this model do not seem very consistent and many of the traces cross each other. These eddies can be seen clearly in TT All Center Traces Section (pg.57) and have a velocity closer to 1 mile per hour, which is within ASHRAE comfort guidelines. The low wall height of our model puts the high velocity air current at an uncomfortable level for standing, but could be a viable strategy for window placement if the room was higher. These eddies do not seem to inhibit the overall exchange rate which is the highest of all our models with an exchange rate of 48.29. The lack of views to the exterior is an additional problem with this windom placement, and fixed windows would need to be added to compensate. The air currents that take place in the vaulted portion of the ceiling are very calm and the speed may not be enough to displace hot air that has stacked towards the top of the room.

Slim Vertical Windows Front and Rear (Model SV)

Model SV has very similar tendencies as Model CC as the placement is similar. The distribution and air velocity of the space is the most consistent between all of the models SV All Center Traces Plan(pg.64). There is a minimal lower eddy under the window as well as a large eddy taking place in the vaulted volume. Model SV had a velocity of 3.0 miles per hour at one foot into the space, with the threshold of comfort reached at approximately 3.5 feet, and threshold of stagnation occuring at approximately 13 feet. The lower entry velocity of the air does not disrupt the space and settles down to a constant velocity in the space making this model the most comfortable according to ASHRAE standards. The air exchange of the main space is 45.9 which is lower than the control Model CC(47.8), but not far behind the highest(48.29). In SV All Traces Plan (pg.71) there is a distinct difference in the side room airflow, like in SS All traces plan, in the south west room of the house there is no rotating currents that leave the space, but just a small slipstream within the space. This model overall has the best air distribution with minimal eddies forming to disrupt the air movement.

Lessons Learned The result of running these tests allows for a better understanding of how air currents move within a space. The factors such as the spacing of windows, their size and shape, interruptions within the space, the shape of the space, and airflow velocity all play into the movement of the air currents. These factors also impact the air exchange rates and although higher air changes result in a fresher space, considering the comfort of the residence, the

maximum velocity of the air needs to be taken into account. The most even distribution of air at a constant velocity, factoring in the ability of the eddy currents to cycle out hot air from the vaulted space, creates the best interior environment. The perpendicular angle of the wind played heavily into the results and one possible next analysis iteration would be to see if our findings still stand with each model as the angle of the air hitting the building changes. Each model shows the complexities of cross ventilation and the diverse path air takes as it enters and leaves the structure. Further research is necessary if we are to be able to question the standards of window placement, in addition to ASHRAE standard guidelines. Our findings concluded that all models have pros and cons to them, but Model SV allowed for the most even distribution of air while still offering views to the outside as well as a high air exchange rate of 45.9 with a low entry velocity. Due to the limited scope of scenarios tested, the data we gathered is not perfect and our findings could not determine the optimal solution for our residential model, and as a result further testing would be required.

Appendix A Reference Images

Image 1

Image 2

Image 3

Appendix B Model Analysis Images

Model CC

CC All Center Traces Section

CC All Center Traces Plan

CC Section Trace 1

CC Plan Trace 1

CC Section Trace 2

CC Plan Trace 2

CC Section Trace 3

CC Plan Trace 3

CC Vector Map Section 1

CC Vector Map Section 2

CC Vector Map Section 3

CC Vector Plan Low

CC Vector Plan Mid

CC Vector Plan High

CC All Trace Plan

Model BB

BB All Center Traces Section

BB All Center Traces Plan

BB Section Trace 1

BB Plan Trace 1

BB Section Trace 2

BB Plan Trace 2

BB Vector Section 1

BB Vector Section 2

BB Vector Section 3

BB Vector Plan Low

BB Vector Plan Mid

BB Vector Plan High

BB All Traces Plan

Model BT

BT All Center Traces Section

BT Trace Section 1

BT Trace Plan 1

BT Trace Section 2

BT Trace Plan 2

BT Vector Section 1

BT Vector Section 2

BT Vector Section 3

BT Vector Plan Low

BT Vector Plan Mid

BT Vector Plan High

BT All Traces Plan

Model SS

SS All Center Traces Section

SS Trace Section 1

SS Trace Plan 1

SS Trace Section 2

SS Trace Plan 2

SS Trace Section 3

SS Trace Plan 3

SS Trace Section 4

SS Trace Plan 4

SS Vector Section 1

SS Vector Section 2

SS Vector Section 3

SS Vector Plan Low

SS Vector Plan Mid

SS Vector Plan High

SS All Traces Plan

Model SH

SH All Center Traces Section

SH All Center Traces Plan

SH Trace Section 1

SH Trace Plan 1

SH Trace Section 2

SH Trace Plan 2

SH Trace Section 3

SH Trace Plan 3

SH Vector Section 1

SH Vector Section 2

SH Vector Section 3

SH Vector Plan Low

SH Vector Plan Mid

SH Vector Plan High

SH All Traces Plan

Model TT

TT All Center Traces Section

TT All Center Traces Plan

TT Trace Section 1

TT Trace Plan 1

TT Trace Section 2

TT Trace Plan 2

TT Vector Section 1

TT Vector Section 2

TT Vecto Section 3

TT Vector Plan Low

TT Vector Plan Mid

TT Vector Plan High

TT All Traces Plan

Model SV

SV All Center Traces Section

SV All Center Traces Plan

SV Trace Section 1

SV Trace Plan 1

SV Trace Section 2

SV Trace Plan 2

SV Trace Section 3

SV Trace Plan 3

SV Vector Section 1

SV Vector Section 2

SV Vector Section 3

SV Vector Plan Low

SV Vector Plan Mid

SV Vector Plan High

SV All Traces Plan

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