Trane Acoustics Program (TAP) Getting Started Guide

TAP™ TRANE ACOUSTICS PROGRAM

Getting Started Guide Getting Started TAP™ Trane Acoustics Program

Version 4.1 LIMITATIONS OF LIABILITY AND DISCLAIMERS

The Trane Acoustics Program (TAP™), whether used by itself or in combination with other software, is intended as a tool for comparative studies of room sound pressure levels generated by various equipment and architectural system layouts. Program accuracy is highly dependent on user-supplied data. It is the user’s responsibility to understand how the data entered affects program output, and to understand that any predefined libraries are to be used only as guidelines for entering that data. The calculation results and reports from this program are meant to aid the building designer and are not a substitute for design services, judgment, or experience.

TRANE, IN PROVIDING THIS SOFTWARE, ACCEPTS NO RESPONSIBILITY OR LIABILITY FOR THE DESIGN OF THE BUILDING OR SUPPORT SYSTEMS, TO INCLUDE IMPLIED QUIET OPERATION.

TRANE SHALL NOT BE LIABLE FOR ANY CLAIMS, CAUSES OF ACTION, OR DAMAGES ARISING OUT OF OR ALLEGED TO ARISE OUT OF THE USE OR INABILITY TO USE THE TRANE ACOUSTICS PROGRAM. UNDER NO CIRCUMSTANCES WILL TRANE BE LIABLE FOR ANY INCIDENTAL, CONSEQUENTIAL, OR SPECIAL DAMAGES, REGARDLESS OF THE LEGAL THEORY ADVANCED.

Trane, the Trane logo, C.D.S, and TAP are trademarks of Trane in the United States and other countries. All trademarks referenced in this document are the trademarks of their respective owners.

Chapter 1 Welcome! Design Tools software download ...... 1–2 Installing (and uninstalling) TAP ...... 1–2 Starting TAP...... 1–2 Learning to use TAP ...... 1–3

Chapter 2 How TAP Works TAP terminology ...... 2–1 Understanding Views ...... 2–2

Chapter 3 Lessons One to Three Lesson One ...... 3–1 Predict sound level from an outdoor chiller ...... 3–1 Evaluating the results ...... 3–3 Lesson Two ...... 3–5 Model two paths to sum sound level at the receiver .. 3–5 Model the discharge-airborne path ...... 3–5 Model the casing-radiated path ...... 3–8 Determine the overall sound level ...... 3–9 Lesson Three...... 3–12 Study a typical acoustical analysis ...... 3–12 TAP Analysis ...... 3–12 Reports ...... 3–14

Chapter 4 Tutorial Notes—Equipment File Notes: Chiller ...... 4–1 File Notes: Fan coil ...... 4–5 File Notes: Rooftop...... 4–6 File Notes: Self-contained...... 4–9 File Notes: Variable Air Volume terminal ...... 4–12

CDS-PRM006-EN • TAP Getting Started iii Chapter 5 Tutorial Notes File Notes: Auditorium...... 5–1 File Notes: Lot line...... 5–6

iv TAP Getting Started • CDS-PRM006-EN 1 Welcome!

This booklet introduces you to version 4.1 of the Trane® Acoustics Program (TAP™). Modeling an HVAC system's acoustical performance entails many complex mathematical equations. Solving these equations manually takes hours of precious design time and is prone to error. TAP dramatically streamlines this process by solving these equations for you. All you need to do is describe the “elements”—equipment and building structural components—that make up each sound path.

Easy-to-use menus and dialog boxes help you create pictorial diagrams of the sound paths with icons that can be rearranged with the click of a mouse. Add, move, redefine, or delete an element icon and TAP dynamically recalculates the resulting sound power levels. When your analysis is complete, view or print the outcome as a series of detailed tables. Or if you prefer, summarize the data graphically on a noise criteria (NC) or room criteria (RC) chart … the choice is yours!

What's in TAP 4.1 for you?

■ Detailed “source-receiver-path” modeling ■ Comprehensive, professional reports ■ Online descriptions of underlying ASHRAE algorithms

TAP is founded on the industry-standard calculations published by ASHRAE in their 1991 Algorithms for HVAC Acoustics manual. Regardless of how many sound-contributing paths are included, the program automatically models the acoustical effect of individual elements and determines the sound level contributed by each path. To estimate overall sound power, drag the desired paths into TAP's Sum View window.

With version 4.1 of TAP, it's easy to accurately predict and compare the sound characteristics of several system alternatives. On the following pages, program basics and application lessons will get you up and running. Learn more about acoustic applications from the online Help within the program.

CDS-PRM006-EN • TAP Getting Started Welcome! 1–1 Design Tools software download

TAP is part of the Design Tools suite. This suite is available for download from the Download Center on www.tranecds.com. The software download includes these components:

■ Executable files for each Design Tools program ■ Getting Started manuals ■ Installation instructions

Installing (and uninstalling) TAP

TAP must be installed on your hard disk; it cannot run off a network. Step-by-step installation instructions are included with the download.

Note: A license is required to activate the software.

Uninstalling the program If you ever need to remove the program from your computer, use the Uninstall Programs function in the Windows® Control Panel. This utility will delete all TAP files—except for those shared by other applications.

Starting TAP

Start TAP just as you would any other Windows program, by doing one of the following

■ Double-click the TAP icon on the desktop. –or–

■ On the Start menu, point to Programs and C.D.S. Applications; then click TAP.

1–2 Welcome! TAP Getting Started • CDS-PRM006-EN Learning to use TAP

The following resources are available to you:

This manual The Getting Started manual will acquaint you with:

■ How the program works (Chapter 2) ■ How to model common scenarios (Chapter 3) ■ How to analyze acoustical models (Chapter 4) Read the manual from cover to cover, or skip directly to Chapter 3 to begin using the program by completing a tutorial.

Online Help TAP’s online Help describes how to perform basic tasks. It also provides detailed information about each program entry, including the equations TAP uses to model an element’s acoustical performance. These industry-standard calculations are published in ASHRAE’s 1991 Algorithms for HVAC Acoustics manual.

To open online Help, do one of the following:

■ On the Help menu, click Contents, or ■ Press F1 for the Help topics related to the currently displayed screen, or ■ Click the Help button on the toolbar.

Web resources Additional sources of information and help are available in the Software area of the Trane Web site. Visit www.tranecds.com for access to our online knowledge base, download center, and training opportunities, and to subscribe for notifications about program updates.

Technical support Your license agreement (renewed annually) entitles you to continued use of the program, free program upgrades, and the latest documentation. As a Trane C.D.S. customer, you’re also eligible for free technical assistance from the experienced HVAC engineers and software specialists in our support center.

CDS-PRM006-EN • TAP Getting Started Welcome! 1–3 Support center hours are 8:00 a.m. to 5:30 p.m. (central time), Monday through Thursday; and 8:00 a.m. to 5:00 p.m., Friday.

phone • 608-787-3926 fax • 608-787-3005 Web site • www.tranecds.com e-mail • [email protected] mailing address • TRANE Attn.: C.D.S. Group 12-2 3600 Pammel Creek Rd La Crosse, WI 54601-7599

Comments? We are committed to continually improving our HVAC design and analysis tools. As you use TAP and discover opportunities to improve its usability, or if you encounter difficulties, please take a moment to let us know by e-mail, fax, or phone.

1–4 Welcome! TAP Getting Started • CDS-PRM006-EN 2 How TAP Works

Put simply, TAP builds and analyzes sound paths by allowing you to choose specific equipment and building components that generate, attenuate, reduce or regenerate sound. TAP has the added enhancement of distinguishing among regeneration (red- shaded icons) attenuation (blue-shaded icons) and both (purple- shaded icons).

Dialog-box entries help you further refine the component characteristics.Each time you add, move or delete a component, TAP automatically updates the sound calculations for that path. When multiple paths are involved—discharge airborne, duct breakout, return and/or casing-radiated—TAP not only determines the overall sound level at the receiver, but also how much of that sound each path contributes.

When your analysis is complete, view or print the outcome as a series of detailed tables. Or, if you prefer, plot the analysis results on a Noise Criteria (NC) or a Room Criteria (RC) chart with TAP’s built-in graph function.

TAP terminology

TAP uses the Source-Path-Receiver model to estimate sound levels. In this model, the source is the sound-generating device, the receiver is typically the site where a person hears that sound, and the path comprises everything that affects the sound as it travels from the source to the receiver. The term elements collectively describes the source, receiver, and path components.

TAP models each user-selected element individually. For proper analysis, the order in which these elements are selected should reflect the direction that sound travels—from the source to the receiver.

The receiver location hears the sum of all sound traveling to that location. Depending on the application, there may be several

CDS-PRM006-EN • TAP Getting Started How TAP Works 2–1 sources of sound and the sound from each source may travel to the receiver along one or more paths. Regardless of the number of sound sources and paths, TAP analyzes each path individually, then calculates the sum using the equations published by ASHRAE in Algorithms for HVAC Acoustics.

Understanding Views

TAP's intuitive interface helps new users quickly learn how to model sound. To begin a new acoustical analysis, select the File menu and choose New. Notice that the main TAP screen contains three subsidiary windows; see Figure 2-1.

The Path View window is where you will place icons representing the source, path components and receiver from the Elements menu and arrange them to depict each sound path.

After you have constructed the path(s), you will use the Sum View window to add the individual paths. Create a Sum header, then drag each path from the Path View window to the newly created Sum header.

2–2 How TAP Works TAP Getting Started • CDS-PRM006-EN Figure 2-1 Main Screen View

Other TAP menus available when this window is active are: File, Edit, Paths, View, Window and Help.

TAP automatically calculates the acoustical performance of the active path as you add, modify or remove elements in the Path View or Sum View, and displays the results in the Table View window. Since this information can't be edited, only the File, View, Window and Help menus are available in the Table View.

Use the View menu to display the resulting RC and NC curves for any of the paths or sums created.

Selecting your criteria The main area of the Trane Acoustics Program lies under Elements, where you select the source, path and receiver entities. The commands provided in that menu are explained in online Help. Open dialog boxes to enter data for your application.

CDS-PRM006-EN • TAP Getting Started How TAP Works 2–3 2–4 How TAP Works TAP Getting Started • CDS-PRM006-EN 3 Lessons One to Three

The best way to familiarize yourself with the Trane Acoustics Program is to use it. To help you get started, practice the step-by- step instructions in the lessons in this chapter.

We also encourage you to open the sample analysis files provided for each lesson called lesson1.tap, lesson 2.tap, etc. They were automatically copied to your hard drive when you installed the program.

Lesson One

Predict sound level from an outdoor chiller

Scenario. A 40-ton Model CGAD air-cooled chiller sits 10 feet from a building and 40 feet from the property line (Figure 3-1). According to a local ordinance, the sound level at the lot line cannot exceed 50 dBA. Does this application of the unit satisfy that requirement?

TAP Analysis. In our first scenario, sound emanating from the chiller (the source) travels along one path to someone (the receiver) with a sound meter standing at the lot line. The path consists of two elements: the sound source itself and the correction factor for the distance separating the source and receiver.

Figure 3-1 Scenario for lesson one

40-ton CGAD Lot line

6 ft 5 ft

10 ft 40 ft

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–1 1 Click anywhere in the Path View window to activate it. 2 On the Elements menu, point to Equipment Sound Sources, Tra n e and click Air-Cooled Chiller. 3 In the dialog box, select CGAD from the Model list and 40 from the Size list. Click OK. This is the first element added to the path, so TAP automatically creates a new path and header (Path1) and adds the chiller icon to it. Note that TAP also updates the Path Table View window to show the addition of this element and its impact on the resulting sound level.

4 The Path1 label conveys minimal information about the nature of the path, but you can easily add a more detailed description. a Click Path1 header to highlight it. b Place the cursor in the Comments box (next to the toolbar) and type CGAD 40 chiller sound at lot line without barrier in the text box.

This description appears on printed reports for this path and displays in the Comments box when the Path1 icon is active.

5 With the Path View window still active (click on it if it’s not), click the chiller icon to highlight it. TAP places the next element to the immediate right of a highlighted icon. 6 On the Elements menu, point to Receiver Sound Correction, and click Outdoor. 7 Use the following information to complete the dialog box entries. (Use the TAB key to move through the dialog box.)

Description Enter Source to Ground 6.0 ft Receiver to Ground 5.0 ft Source to Receiver 40.0 ft Sound source near a Ye s vertical reflecting surface? (building) Source-to-Surface 10.0 ft Distance Barrier between source No and receiver? (default)

3–2 Lessons One to Three TAP Getting Started • CDS-PRM006-EN 8 Click OK to close the dialog box.

The Outdoor Correction icon is added to the path and a corresponding line of data is displayed in the Table View window.

Our initial TAP analysis is now complete.

Evaluating the results Review the data presented in the Table View window. TAP sums the overall sound pressure by octave band and calculates the overall NC, RC, and dBA values. In this lesson, the path analysis predicts an overall rating of 67 dBA at the lot line—a value considerably higher than the 50 dBA target.

One way to reduce this sound level is to add an acoustical barrier between the chiller and the lot line. To model the acoustical effect of this addition, you will need to redefine the “Barrier Between Source and Receiver?” characteristics of the Outdoor Correction element. Rather than modify the original path, duplicate it and alter the copy instead.

With the Path View window active and the Path1 header highlighted:

1 On the Paths menu, click Copy; then click Ye s to duplicate the path.

You can resize TAP automatically scrolls the newly created path into view. To any of TAP's see both paths simultaneously, adjust the scroll bar at the right subsidiary side of the window. windows by dragging it to 2 Select the Path2 header, click in the Comments box and type the desired size. CGAD 40 chiller sound at lot line with barrier between. 3 Double-click the Outdoor Correction icon (element) in Path2 to reopen the dialog box that defines it. 4 Change the Barrier Between Source and Receiver? value to Ye s . For now, use the default values to model a barrier that's 10.0 feet high and 6.0 feet from the chiller. Click OK. 5 With the Outdoor Correction icon still active, click the Comments box and type Added a 10-ft-high barrier 6 ft from the chiller. Unlike path header comments that only appear on printed reports, a comment attached to an element also appears in the

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–3 Ta b l e Vi e w window next to the appropriate line of acoustical data.

Note that the Ta b l e Vi e w window now displays the acoustical TAP estimates acoustical analysis results for Path2. The addition of the barrier reduced performance. the overall rating at the lot line to 51 dBA. Although you're not Build a safety asked to do so in this exercise, you could reopen the Outdoor factor into your Correction element's dialog box and increase the barrier height analyses— to 11 ft to achieve the target value of 50 dBA. especially in sound-critical 6 To save this TAP analysis, open the File menu and click either applications. Save or Save As. Identify the destination drive and directory, type the desired file name, and click Save. TAP saves the file with a .tap extension. 7 On the View menu, click Project Info. The dialog box allows you to record general information about the project that appears as a header on all printed reports for that project. An example of this dialog box, complete with entries, appears in Figure 3-2.

Note: TAP automatically completes the File Name and Run Date boxes. These entries can’t be edited.

8 Either complete the text boxes and click OK to save your entries, or click Cancel to close the dialog box.

Figure 3-2 Project information dialog box

3–4 Lessons One to Three TAP Getting Started • CDS-PRM006-EN Lesson Two

Model two paths to sum sound level at the receiver In the previous lesson, sound followed a single path from the source to the receiver. Typically, two or more paths convey sound between these points.

Scenario. The VAV box located above a conference room produces sound that reaches the occupants below. That sound moves along two paths: it travels with supply air through the diffuser along the discharge-airborne path, and it passes directly from the VAV box through the ceiling along the casing-radiated path. See Figure 3-3.

Figure 3-3 Scenario for lesson two

8 ft

15 ft

20 ft To determine the overall sound level in the conference room, model each path individually, then combine the results.

Model the discharge-airborne path The discharge-airborne path consists of the discharge sound power of the VAV box (the source), 6 ft of lined round duct, a diffuser and the room correction factor (the receiver). As in the preceding lesson, add each element to the path separately and in the direction of sound travel.

Add the VAV box TAP doesn't include sound data for VAV boxes. To model that element of the path, use the Custom option to provide its cataloged acoustical performance.

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–5 1 On the File menu, choose New; then click the Path View window to activate it. 2 On the Elements menu, choose Custom. 3 On the Custom Element dialog box, click the Sound Source (Logarithmic Addition) option button if it is not selected. 4 Type the following cataloged unit sound data in the appropriate Decibel Level (dB) text boxes. The 63 Hz entry is not needed.

Hz dB Hz dB 125 65 1 k 56 250 61 2 k 48 500 58 4 k 42

5 In the Comments box, type Discharge Lw for a size 03 VCCE terminal unit at 300 cfm, 1.5 tsp. Click OK.

Add the duct To add the duct to the immediate right of the Custom Element icon, make sure that icon is highlighted. Then:

1 On the Elements menu, point to Duct Sound Attenuators and click Straight Duct. 2 In the Type section of the dialog box, select Circular/Lined. 3 Enter these values in the Dimensions section:

Description Measurements Inside diameter 8 in. Duct length 6 ft Lining thickness 2 in.

4 Click OK.

Add the diffuser With the Straight Duct (CL) icon still highlighted:

1 On the Elements menu, point to Duct Sound Regenerators, and click Diffuser. 2 On the dialog box, choose Generic Type/Dimensions (if it's not already selected) as the Basis of Calculation.

3–6 Lessons One to Three TAP Getting Started • CDS-PRM006-EN 3 In the Diffuser Type/Characteristics section, select Rectangular Slot as the diffuser type and add these values. (Use the TAB key to move through the dialog box.)

Description Measurements Pressure drop 0.15 in. wg Duct flow volume 150 cfm Inside height 36 in. Inside width 1 in.

4 Click OK to close the dialog box and add a Diffuser icon to the path.

Add the receiver correction factor Finally, complete the path by adding the room or receiver correction factor. With the Diffuser icon still highlighted:

1 On the Elements menu, point to Receiver Sound Correction, and click Indoor. 2 Select 1991 ASHRAE in the Room Equation section of the dialog box. 3 Enter these values in the Receiver Room section. (Use the TAB key to move through the dialog box.)

Description Entry Height 8 ft Width 15 ft Length 20 ft

4 Select Distributed Ceiling Diffusers as the Type of Source, and complete these entries:

Description Entry Average source-to-receiver distance 5 ft Number of sound sources/diffusers 2 Area served by each diffuser 150 sq ft Use Environmental Adjustment Factor (EAF) Ye s for Schultz’s equation?

5 Click OK to close the dialog box. TAP adds an Indoor (91 ASHRAE) icon to the path. 6 Click the Path1 icon; then click in the Comments box and type VAV discharge-airborne sound.

The Table View displays the sum and NC rating for this path, as well as the octave band data for each of its elements.

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–7 View NC and RC plots of this information 1 Highlight any of the icons in the desired path. 2 On the View menu, select NC/RC Chart. 3 To switch from one graph to the other, choose the appropriate option button. 4 If desired, click Print for a paper copy. Click OK to return to the main TAP window.

Model the casing-radiated path The casing-radiated path consists of three elements: the radiated sound power of the VAV box (the source), the attenuating effect of the ceiling, and the room correction factor (the receiver).

Add the VAV box With the Path View window active:

1 On the Paths menu, click New. TAP adds a Path2 icon below Path1. 2 Before adding any elements, name the new path. Click once on the Path2 icon; then click in the Comments box and type VAV casing-radiated sound. 3 To model the VAV box, click the Path2 icon. On the Elements menu, click Custom. 4 Click the Sound Source (Logarithmic Addition) option button if it's not already selected. 5 Type the following radiated sound power (Lw) values in the appropriate Decibel Level text boxes. (Use the TAB key to move through the dialog box.) Be sure to omit the 63 Hz entry.

Hz dB Hz dB 125 54 1 k 39 250 49 2 k 33 500 45 4 k 27

6 In the Comments box, type Radiated Lw for a size 03 VCCE terminal unit at 300 cfm, 1.5 tsp. Click OK.

3–8 Lessons One to Three TAP Getting Started • CDS-PRM006-EN Define the ceiling loss element 1 Click the newly added Custom Entry icon. On the Elements menu, point to Sound Transmission, and click Ceiling System. 2 On the dialog box, click Acoustical Tile/Exposed T-Bar and choose 2 ft × 2 ft × 5/8 in.; Surface Wt = 0.95 - 1.1 lb/sq ft from the drop-down list. 3 For the Integral Lighting, Diffusers or Other Penetrations? entry, click Ye s ; then click OK.

Define the room correction factor to complete the path 1 Click the Ceiling System icon (if it isn't already selected). On the Elements menu, point to Receiver Sound Correction and click Indoor. 2 Select Regression as the Room Equation. 3 Enter these values in the Receiver Room section:

Description Entry Height 8 ft Width 15 ft Length 20 ft Average source-to-receiver distance 5 ft No. of sound sources/diffusers 1

4 In the Acoustical Characteristics of Room section, select Medium Dead: Acoustical ceiling, commercial carpet. 5 Click OK.

Check the Table View to see the octave band data for each element, along with Path2's sum and NC rating.

Determine the overall sound level in the conference room The discharge-airborne and casing-radiated path results must be combined. To sum these paths:

1 Click on the title bar of the Sum View window. Note: Activating this window “replaces” the Elements and Paths menus with the Sums menu.

2 On the Sums menu, click New. TAP adds a Sum 1 icon to the Sum View window. Click Sum 1 to activate it.

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–9 3 Move to the Path View, select Path1 icon and drag it onto the Sum 1 icon. 4 Return to the Path View, select Path2 icon and drag it to the immediate right of the Path1 icon.

That completes the TAP analysis for this scenario. To view the sum of Paths 1 and 2 in the Ta b l e V i e w window (Figure 3-4), activate the Sum View window by clicking once on the Sum 1 icon. As you can see, the discharge sound power of the VAV box has the greatest effect on the conference room's overall sound level.

Figure 3-4 Lesson two Path, Sum, Table Views

3–10 Lessons One to Three TAP Getting Started • CDS-PRM006-EN To display the Table View data as curves plotted on an NC or RC chart, highlight the Sum 1 icon and choose NC/RC Chart from the View menu.

Figure 3-5 shows how TAP displays the sum of Paths 1 and 2 when plotted on an NC graph. Radio buttons allow you to switch between NC and RC plots. Click Print for a hard copy of the displayed graph.

Figure 3-5 TAP display of NC chart for lesson two

To print the tabular data for a particular path or sum, highlight the desired Path or Sum icon and choose Print from the File menu.

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–11 Lesson Three

Study a typical acoustical analysis The intent of the preceding lessons was to acquaint you with the basic organization and functions of TAP. While Lessons One and Two described “real” situations, a typical acoustical analysis is usually more complicated. Lesson Three presents a more true-to- life case.

Scenario. The equipment room next to a conference room houses a commercial self-contained unit (Figure 3-6). Four paths convey the sound produced by this unit into the conference room:

■ the discharge-airborne path (D) ■ the discharge breakout path (C) ■ the return-airborne path (B) ■ the wall-transmission path (A)

Model each path individually; then sum the results to determine the overall sound level in the conference room.

Figure 3-6 Four paths in a self-contained system

C D 8 ft 20 ft B

40 ft

TAP Analysis When you installed TAP, three sample analysis files, one for each lesson, were copied into the TAP directory on your hard drive. Since you now know how to build and sum paths, we will not describe those steps again. Instead, open lesson3.tap.

Double-click on each element icon to see how the dialog-box entries define the acoustical properties. You will discover that

3–12 Lessons One to Three TAP Getting Started • CDS-PRM006-EN some of the information provided is not presented in Figure 3-7. As is often the case on the job, assumptions were made to sufficiently define the elements for acoustical analysis.

Figure 3-7 Scenario for lesson three Plan View

15 in. x 30 in.

40 ft

Conference Room 6 ft 20 ft 15 ft 12 in. x 20 in., 6-in. dia. 3,000 cfm 22 ft

12 in. x 40 in., 6,000 cfm 6 ft 12 in. x 40 in., 6,000 cfm

Equipment Room Side View Equipment Room End View 30 ft 18 ft Return Air Duct Discharge Plenum 12 in. x 40 in., 6,000 cfm 12 ft Commercial Self-Contained 10 ft Unit Return Air Grille 5 ft 15 ft Return Air

Equipment room walls are constructed of 8-in. Commercial Self-Contained Unit poured concrete and are unpainted. Model SWUA, Size 30, Fan Speed = 1,050 rpm, The conference room has an 8-ft acoustical-tile 12,000 cfm at 3.0 in. wg TSP ceiling and is furnished, carpeted, and served by one 30-in. circular diffuser that delivers supply air at Octave Band (Hz) 63 125 250 500 1k 2k 4k 8k 600 cfm. Discharge Lw 80 90 67 64 66 61 60 54 All rectangular ductwork is covered with 2-in. acoustical lining. Inlet & Cabinet Lw 89 84 79 77 79 76 72 67

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–13 Reports

TAP analysis reports can be exported in a variety of file types. Exporting instructions are provided below; sample reports from Lessons One through Three are on the following pages.

To export a report 1 From the View menu, point to Reports and click the desired report. The Report Viewer displays the selected report. 2 On the Report Viewer File menu, point to Export, and click either All reports or Current report. 3 Select the desired file type from the Export Format or Save As Type drop-down list box. Click OK or Save.

Figure 3-8 Export screen for All reports option

Figure 3-9 Export screen for Current report option

3–14 Lessons One to Three TAP Getting Started • CDS-PRM006-EN Figure 3-10 Sample reports for the first three lessons

CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–15 3–16 Lessons One to Three TAP Getting Started • CDS-PRM006-EN CDS-PRM006-EN • TAP Getting Started Lessons One to Three 3–17 3–18 Lessons One to Three TAP Getting Started • CDS-PRM006-EN 4 Tutorial Notes—Equipment

The previous chapters walked you through the basics of the TAP program. The challenge is to correctly interpret additional information in real-life equipment scenarios to make decisions. This chapter will analyze information that an engineer would typically review during a project. All the tutorial files have been saved to your computer and are located under My Documents\ Trane Acoustics Program Projects. Modeling examples in this chapter:

■ Chiller, page 4–1 ■ Fan coil, page 4–5 ■ Rooftop, page 4–6 ■ Self-contained, page 4–9 ■ Variable Air Volume (VAV) terminal, page 4–12

File Notes: Chiller

Description of System. A chiller located in the equipment room adjacent to an occupied space. In this case, the equipment room is located below the receiver room.

Similar systems. The chiller could be replaced by any type of sound-generating equipment. There may also be multiple pieces of sound-generating equipment in the room. The receiver room could be located above, below or beside the equipment room.

Note: If the sound-generating equipment is an air handling unit, see the example “File Notes: Self-contained” on page 4–9.

What makes it unique/difficult to model. This is a simple model. The only complicating factor is caused by the definition of the sound data in terms of sound pressure rather than sound power.

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–1 Difficulties arise if there is an intermediate space, such as a hallway, between the equipment room and the receiver room. You can make an estimate for the intermediate space, because the ASHRAE algorithms are not designed to handle these spaces.

Modeling tips. The sound path considered here is ceiling transmission. TAP calls the path Wall Transmission, but the path applies to walls, floors, and ceilings. It is important to note that TAP only considers airborne sound. Structure-borne vibration may cause additional sound problems in the occupied space. Because vibration effects are difficult to calculate, a good approach is to ensure the equipment is well isolated from the building structure.

Figure 4-1 Ceiling transmission

Path 1 accounts for the sound transmission through the ceiling of the equipment room. The first element in the path is the sound data for the chiller. In this case, the sound data is provided in terms of pressure rather than power. A custom element is incorporated to adjust the data to approximate sound power.

For a point source in a flat-plane, free-field environment, we calculate the rate at which sound drops as we move away from the source. In this case, the sound pressure data was taken one meter from the unit. If the unit was a point source, the sound pressure would be 12 dB less than the sound power at one meter. The relationship between power and pressure doesn’t hold up perfectly because the unit has a considerable surface area compared to a point source. The correction at one meter may vary, depending on unit size, from 8 to 20 dB. The unpredictable value for this correction reduces the accuracy of the prediction.

4–2 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN Figure 4-2 Wall transmission

The calculation of sound transmission through a wall is divided into three components. The first component is the wall or floor, which calculates the change in sound power from the equipment to the wall. This change depends on the size of the room containing the equipment, the absorptivity of the room, how the source radiates and the distance from the source to the wall. The wall type in this room may differ from the transmission surface. For example, the equipment room may have a gypsum board wall but a poured concrete ceiling. The transmission surface will affect the equipment sound.

The second component, represented by the Trans Loss Val element, accounts for the transmission loss through the wall (or ceiling, in this case). Transmission loss values for several construction types are available in the program. To calculate transmission loss, enter the surface weight and thickness of the material or enter the transmission loss values directly. In each case, apply an adjustment factor to account for sound leakage through openings in the structure. Use the Quality of Construction information to adjust for the openings.

The final component is the room correction. Wall transmission uses a unique room correction equation to evaluate the sound radiating from a flat surface.

Path 2 shows the effect of adding absorbing materials to the equipment room. It was created by copying Path 1, opening the Wall or Floor element and adjusting the Sound Absorption Characteristics section of the dialog box. Because the frequency content of this source is weighted to the middle and upper bands, two inches of three pounds density insulation on the walls effectively reduced the sound levels in the occupied space.

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–3 Figure 4-3 Path 2

4–4 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN File Notes: Fan coil

Description of system. A fan coil unit located in an occupied room.

Similar systems. The fan coil could be replaced by any type of sound-generating equipment. There may also be multiple pieces of sound-generating equipment in the room.

What makes it unique/difficult to model. This is a straightforward model. If there were multiple units in the room, along one wall for example, it might be necessary to account for the effect of distant units using multiple paths.

Modeling tips. The room size, absorptivity, and distance from the source to the receiver are major considerations when the acoustic modeling is determined.

Figure 4-4 Fan coil

8 ft

15 ft

20 ft

Table 4-1 Size 03 Vertical cabinet fan coil, medium speed

Octave Band (Hz) 63 125 250 500 1k 2k 4k Discharge Lw 56 55 52 48 44 37 30

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–5 File Notes: Rooftop

Description of system. A 20-ton packaged rooftop located above an open plan office space.

Similar systems. Packaged air-handling roof-mounted equipment where the sound concern is a space served by the equipment.

What makes it unique/difficult to model. It takes five sound paths to completely model this arrangement: Four duct paths and one roof transmission path.

Packaged rooftop units concentrate several sound sources in a small area. It is important to consider all of the sources and various paths.

Modeling tips. Typically the highest sound levels are in an area close to the unit because of the limited opportunity for attenuation and the concentration of sound sources. If the unit is located directly over occupied space, the “worst case” receiver location will typically be directly below the supply duct. If the area directly under the unit isn't sound sensitive, several receiver locations may need to be modeled to determine the worst case location.

The five sound paths that make up this model are:

■ supply airborne ■ supply breakout ■ return airborne ■ return breakout ■ roof transmission

Supply airborne starts with the discharge sound of the unit. Elements are added to account for the various pieces that make up the duct path. Follow the airflow from the unit discharge to the diffuser closest to the receiver location. In this example, there is only one diffuser near the unit. If there were several diffusers near the unit, they could be accounted for in the room correction element.

4–6 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN Supply duct breakout accounts for the sound that breaks through the wall of the supply duct, down through the ceiling tile and into the occupied space. Because sound generally is attenuated as it travels down ductwork, duct breakout is typically worst near the unit. This sound path is the same as the supply airborne path until the first large section of duct above the occupied space is encountered. Since these paths share a few elements, it can be a time savings to use a path branch as shown.

Breakout is accounted for using the duct breakout element (located on the Elements menu, under Sound Transmission). Next comes a ceiling transmission loss element and then the room correction. Choose the room correction equation associated with duct breakout.

Breakout sound can be reduced by switching from rectangular to round (or multiple runs of round) duct, or by adding lagging to the ductwork. Several lagging options are available on the Elements menu, under Sound Transmission > Lagging.

Return airborne accounts for the sound coming from the inlet to the unit. Without return ductwork, this path simply consists of the inlet sound data for the unit, a ceiling transmission loss and a room correction. The return path can be attenuated by adding ductwork, with one or more tee junctions, to the unit. There are several benefits to adding ductwork:

■ attenuation in the duct, especially if it is lined ■ return sound moves away from the other unit sounds ■ sound power split at tee junctions breaks the return sound into multiple smaller sound sources ■ duct-end reflection loss at duct termination

Duct-end reflection is a significant method for reducing low- frequency sound. It is only appropriate to take this credit when the duct termination is free of disturbances (no grills, diffusers or dampers) and there are four equivalent diameters of straight duct upstream of the opening (no elbows, dampers, etc.). The end reflection credit increases as the duct size decreases. Adding additional tees to reduce the duct size and increase the end reflection can significantly reduce low-frequency sound from the return duct.

Return duct breakout should be modeled if return duct is added to the inlet of the unit. This path is similar to the supply duct

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–7 breakout path in structure. Note that the sound split is taken for the tee, but the duct length used is the entire section of horizontal duct.

Roof transmission accounts for sound that is radiated from the cabinet of the unit and then travels down through the roof into the occupied space below the unit.

Sound can also be transmitted through the portion of the roof within the roof curb. This path is difficult to predict because data does not exist for sound radiated from the bottom of the unit. Construction detail plays a major role in determining the sound contribution of this path. The roof should only be cut away enough to let the ducts pass through and any space around the ducts should be sealed with acoustical mastic. If careful attention is paid to the construction details, the sound transmission through the area within the curb should be similar to the sound transmitted through the roof outside of the curb.

After all these sound paths are created and summed as shown in the “Tutorial Rooftop” file, it is easy to see which sound paths are contributing to the overall sound level in the space. In this example, the NC for the receiver location is 46. By viewing the NC chart (with the Sum highlighted, go to the View menu and select NC/RC Chart), it is possible to see which octave band(s) are setting the overall NC for the space. In this example, there are three octaves—63, 125, and 250—that lie along the NC46 line.

With Sum highlighted, view the path totals in the Table view. For this example, the Supply Duct Breakout is dominant in the 63Hz band, while the Return Airborne is dominant in the 125 and 250 Hz bands. As a result, both of these paths must be attenuated to drop the space NC level.

As paths are modified, the process of reviewing the sum for the dominant path must be repeated. Also note that the overall NC may be set by the additive effects of two or more paths. This is particularly true after the dominant path has been attenuated.

4–8 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN File Notes: Self-contained

Description of system. A 30-ton self-contained unit located in a mechanical equipment room adjacent to an open-plan office space.

Similar systems. Air-handling units located in equipment rooms adjacent to occupied space.

What makes it unique/difficult to model. It takes five sound paths to completely model this arrangement correctly. Four of the paths are duct paths, while the fifth models the sound transmission through the wall. While this model shares many similarities with the Rooftop model, there are two major differences:

■ Wall transmission is easier to calculate than roof transmission. ■ A return path is modeled that is not directly connected to the unit.

Modeling tips. The highest sound levels are typically found in an area close to the unit because of the limited opportunity for attenuation. In this example, the most likely worst case receiver location is in the adjacent conference room. If the area directly adjacent to the equipment room is not sound sensitive, several receiver locations may need to be modeled to determine the worst case location.

The five sound paths that make up this model are:

■ supply airborne ■ supply breakout ■ return airborne ■ return breakout ■ wall transmission

The supply airborne path (Path 1) starts with the discharge sound of the unit. Elements are added to account for the various pieces that make up the duct path—simply follow the airflow from the unit discharge to the diffuser closest to the receiver location.

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–9 Supply duct breakout causes the sound that moves through the wall of the supply duct, down through the ceiling tile, and into the occupied space. Sound is generally attenuated as it travels along ductwork, thus duct breakout is typically the worst near the unit. This sound path is identical to the supply airborne path until the first large section of duct above the occupied space is encountered. These paths share several elements, so it can save time to use a path branch as shown.

Return airborne accounts for the sound traveling opposite the return airflow. In this example, the return duct does not connect to the unit; however, a short piece of return ductwork transfers the return air from the plenum area into the mechanical room. Sound radiates from the unit into the mechanical room. A portion of this sound enters the return duct opening.

This sound path starts with the inlet sound of the unit and adds a hole in the wall. This element calculates the portion of the unit’s radiated sound that exits through the return duct hole.

The return air path could have been designed as simply a hole in the equipment room wall; however, there are several benefits to adding ductwork:

Duct end reflection is a significant method for reducing low- frequency sound. It is only appropriate to take this credit when the duct termination is free of disturbances (no grills, diffusers or dampers) and there are four equivalent diameters of straight duct upstream of the opening (no elbows, dampers, etc.). The end reflection credit increases as the duct size decreases. Adding additional tees to reduce the duct size and increase the end reflection can significantly reduce low-frequency sound from the return duct.

After the duct end reflection element, there is a ceiling transmission loss element and a room correction.

Return duct breakout should be modeled if the return duct travels over the receiver area being analyzed. This path is similar to the

4–10 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN supply duct breakout path in structure. Breakout sound can be reduced by switching from rectangular to round duct (or multiple runs of round duct). Another alternative is to add lagging to the ductwork. Several lagging options are available on the Elements menu under Sound Transmission > Lagging. In this example, return duct breakout is not modeled because an insignificant amount of return duct runs over the receiver room.

Wall transmission accounts for sound that is radiated from the casing of the unit, and the inlet in the case of an unducted return, and then travels through the wall into the occupied space adjacent to the unit. For the example shown, the Wall Transmission path starts with the Inlet plus Casing sound data for the unit. The next three elements are created by choosing Elements > Sound Transmission > Equip Room Wall > Wall or Floor.

The calculation of sound transmission through a wall is broken into three elements. The first of these is the Wall or Floor element, which calculates the change in sound power from the equipment to the wall. The change in sound power is dependent on the size of the room that the equipment is in, its absorptivity, how the source radiates, and the distance from the source to the wall. Wall Type in this box may be different than the construction of the transmission surface. For example, the equipment room may have gypsum board walls, but transmission through the poured concrete ceiling is the concern.

The second element is the transmission loss through the wall (represented by Trans Loss Val). Transmission loss values for several construction types are available in the program. This loss can also be calculated by entering surface weight and thickness of the material or by entering the transmission loss values directly. In each case, apply an adjustment factor to account for sound leakage through structure openings. Use the Quality of Construction screen to adjust the information.

The final component is the room correction. Wall transmission uses a unique room correction equation to account for sound radiating from a flat surface.

The three components can be opened and changed individually as needed. After all these sound paths are created and summed, as shown in the file Self-contained, it is easy to see which sound paths contribute to the overall sound level in the space. By viewing the NC chart (with the Sum active, select View > NC/RC Chart) it is possible to see which octave band(s) are setting the

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–11 overall NC for the space. With Sum still active, look at the path totals in the Table view to see which path or paths are setting the space sound level.

File Notes: Variable Air Volume terminal

Description of system. A VAV unit is located in the plenum space above an occupied room.

Similar systems. The VAV unit could be replaced by any type of sound-generating equipment, such as a water source heat pump or concealed fan coil, located above the ceiling tile. There may also be multiple pieces of sound-generating equipment in the plenum.

What makes it unique/difficult to model. This model is more complicated than the fan coil example because there are separate sound paths for airborne sounds and casing radiated sounds as shown in Figure 4-5.

Figure 4-5 VAV terminal

A 8 ft

15 ft

20 ft

Table 4-2 Size 03 Vertical terminal unit, 300 cfm, 1.5 tsp

Octave Band (Hz) 63 125 250 500 1k 2k 4k Radiated Lw N/A544945393327 Discharge Lw N/A656158564842

■ Sound path 1 is discharge airborne ■ Sound path 2 is casing radiated

4–12 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN Modeling tips. This example only considers the sound generated by the VAV unit. When the VAV unit is connected to the main supply duct system, the sound traveling along that duct adds to the sound generated by the VAV unit. VAV units are typically widely spaced along the duct system, so the acoustical effect of a single unit is considered in a path. In a case where multiple units are mounted close together, it may be necessary to account for the effect of several units using multiple paths.

As shown in Figure 4-5, there are two sound paths to consider: the discharge airborne sound and the casing radiated sound. In some cases, the VAV box may have a return opening to the plenum area but this opening is rarely ducted. Should a ducted return exist, it too must be considered as a separate path.

VAV analysis begins with accurate sound data that is in accordance with AHRI Standard 880 and is certified. Information for the 63 Hz octave band is not included, because VAV boxes are not usually major sound contributors in this band.

The discharge path starts with the VAV box data and includes any ductwork elements, a diffuser, and a room correction as shown in Path 1. The casing radiated path is simple and generally consists of the VAV box sound data, a ceiling transmission loss line, and a room correction as shown in Path 2.

Contractors often attach flex duct to the final sections of duct runs. While TAP does not include flex duct transmission-loss data, this information is readily available in both the ASHRAE handbook and in AHRI Standard 885.

Should you want to include the contribution of sound from the supply duct, add the discharge airborne path to the end of the supply airborne path from the main fan. The path starts with the main fan sound data and includes all the duct elements between the main fan and the VAV box. To counter the plenum effect created when the supply duct sound enters the VAV box, a Terminal Volume Regulator (Elements > Duct sound Attenuators > Te rm i n a l Volume Regulator) can be inserted immediately before the VAV box data element.

In general, you can reduce VAV box noise by oversizing the box to slow down airflow through the box. The location of the box and the ceiling type are critical elements in noise reduction along the casing radiated sound path. Further reduction of discharge

CDS-PRM006-EN • TAP Getting Started Tutorial Notes—Equipment 4–13 airborne sound is accomplished through the use of lined duct, increased duct lengths, elbows, and quieter diffusers.

4–14 Tutorial Notes—Equipment TAP Getting Started • CDS-PRM006-EN 5 Tutorial Notes

Chapters 1–3 walked you through the basics of the TAP program. The challenge is to correctly interpret additional information in real-life equipment scenarios to make decisions. This chapter will analyze information that an engineer would typically review during a project. All the tutorial files have been saved to your computer and are located under My Documents\Trane Acoustics Program Projects. Modeling examples in this chapter:

Auditorium, page 5–1

Lot line, page 5–6

File Notes: Auditorium

Description of system. Air handling equipment is mounted in a large (70 × 100 × 24 ft) auditorium with the unit and the ductwork exposed. The supply duct runs terminate in free space, not at diffusers. The room has a hard floor and walls with a high ceiling.

Similar systems. Industrial applications that provide outside air or cooling to a process, manufacturing, warehouse or storage space.

What makes it unique/difficult to model. Aspects that make this building difficult to model include:

■ room size, ■ equipment distribution, and ■ reverberancy (or hardness) of the room.

The room size and the reverberancy of the room affects the accuracy of the room correction equations. The equipment distribution requires some judgment about the location of the sound receiver.

CDS-PRM006-EN •TAP Getting Started Tutorial Notes 5–1 Modeling tips. There are three primary sound paths in this auditorium: supply (discharge) airborne, supply (discharge) breakout, and casing radiated. Return paths are not considered in this scenario because this unit supplies 100% outside air through a very short return duct. If the return was at least partially drawn from the space or if the return duct to the unit was long enough to consider duct breakout, return paths would have to be considered.

The critical sound area is the space near the air-handling unit (AHU) because it will be affected by all three paths.

■ Path 1, the Discharge Breakout path, looks at the breakout contribution from the first 20 feet of supply ductwork. Although the supply duct is considerably longer, the first portion of the duct affects the receiver location. If a receiver location farther from the AHU were chosen, the attenuating effects of the additional ductwork and junctions would also be considered. ■ Path 2, the Discharge (supply) Airborne, looks at the contribution of sound from the open ends of the supply ducts nearest to the AHU. A duct end reflection credit is taken at the end of the supply duct because there isn’t a diffuser or grill on the end of the duct, and there are at least four equivalent duct diameters of straight duct upstream of the opening.

5–2 Tutorial Notes TAP Getting Started • CDS-PRM006-EN Figure 5-1 Auditorium ductwork

70 x 100 x 24 ft room

18 x 32, 15 ft, 5600 cfm

10 x 10, 152 ft, 700 cfm 10 x 10, 12 ft,700 cfm

18 x 40, 10 ft, 7000 cfm

air handling unit

While the 1991 ASHRAE room correction equation is typically used for distributed sound sources like diffusers, the regression equation is used with this example. The 1991 ASHRAE equation is limited to use with “typical office environments.” The space under consideration here is too large and too hard to be considered typical office space.

The supply airborne ductwork creates 10 sound sources, although only six are considered in the room equation. Because sound is attenuated as it travels down the ductwork and then back across the room, the contribution of sound from a distant diffuser (in this case, duct opening) will be significantly less than the contribution from the diffusers close to the unit. Determining how many diffusers to include can be made by a judgment call or can be calculated by creating multiple paths, starting with the closest diffuser and then moving to more distant diffusers. The “Ave. source to receiver distance” entry in the room correction element should reflect the distance to the same receiver location. The

CDS-PRM006-EN • TAP Getting Started Tutorial Notes 5–3 contribution of each diffuser (or pair) is then added in the Sum View. When the addition of an individual diffuser path no longer affects the total, the sound contribution has become insignificant and more distant diffusers can be ignored.

■ Path 3 duplicates Path 1 with two inches of additional lining ■ Path 4 duplicates Path 2 with two inches of additional lining ■ Path 5 accounts for the sound radiated from the cabinet of the AHU. This is a simple path because the unit is located in the occupied space.

Sum 1 shows the total of the three primary paths as installed. The contractor on this job was convinced that lining the ductwork would solve the sound problems.

Sum 2 shows the total sound with lining in the duct. Notice that there was no reduction in the NC level even though there was a considerable reduction in the two supply paths. This is because the sound spectrum is set by the casing path, not the supply path.

The casing path must be addressed if the space sound level is to be reduced. The most common method of reducing the casing sound is to build an enclosure with sufficient transmission loss around the unit. For example, the enclosure could consist of a stud frame structure with multiple layers of gypsum board on the outside and some absorptive lining on the inside.

5–4 Tutorial Notes TAP Getting Started • CDS-PRM006-EN Figure 5-2 TAP file for auditorium

CDS-PRM006-EN • TAP Getting Started Tutorial Notes 5–5 File Notes: Lot line

Description of system. Three air-cooled chillers located adjacent to a building. The sound concern can be found at three different locations along the property lines labeled A, B and C.

Similar systems. Any sound source, or multiple sources, located outside the building where the sound concern is across open space to a distant location.

What makes it unique/difficult to model. As shown in Figure 5-3, there are several components that make this complicated. There are two types of barriers, multiple sound sources, and reflective surfaces.

Modeling tips. The information provided in the Lot Line file provides the foundation for this example and should be reviewed.

The calculation for outdoor distance correction assumes the source is a point source. Multiple chillers can be modeled as a group if, from the perspective of the receiver, they appear as a point source. When in doubt, the chillers can be modeled individually and summed.

The file shows both methods for comparison. In this example, there are three locations where sound from the chillers is a concern. The closest, point C, is 40 feet from the nearest chiller. Path 1 shows the analysis assuming all three chillers can be grouped as a point source. It consists of the three chillers and an outdoor distance correction. Notice that a barrier effect is not added for the chain-link fence, because it is too open to block any sound. A reflecting surface is placed 11 feet from the “source,” which is a centrally located point between the chillers. The result of the calculation is 85 dBA at point C.

To determine if grouping the chillers together was a valid assumption, we can calculate the contributions of each chiller separately and add them together. Paths 2,3, and 4 show the calculation for chillers 1, 2 and 3, respectively, to point C. Chillers 1 and 2 are located four feet from a reflecting surface and 54 feet from the receiver. Chiller 3 is located 18 feet from a reflecting surface and 40 feet from the receiver.

5–6 Tutorial Notes TAP Getting Started • CDS-PRM006-EN Figure 5-3 Lotline 3 c 40 ft

multi-story building chainlink fence

chiller 3 RTAA 340

14 ft

chiller 1 chiller 2 RTAA 140 RTAA 340

70 ft 35 ft A 4 ft

60 ft

B These individual contributions are combined using the Sum window. Sum 1 shows that the result of adding Paths 2, 3 and 4 is also 85 dBA.

This process can be repeated for receiver location B. The major difference between receiver locations C and B is the eight foot barrier between the chillers and point B. Using the grouped method as shown in Path 5, the level is 70 dBA. When the chiller contributions are calculated separately and summed, the result is 72 dBA.

If the process is repeated for location A, the results are similar. The major difference is that when calculating the individual chiller contributions, the building acts as a barrier to the sound from Chiller 3. We ignored the building effect for the grouped method at point A. The building has a significant barrier effect on Chiller 3 but the sound levels are maintained due to the contribution from Chiller 2.

In this example, the grouped vs. individual methods yielded very similar results. This is not always the case. If there is any question

CDS-PRM006-EN • TAP Getting Started Tutorial Notes 5–7 as to whether the chillers can be grouped, it is best to calculate the chiller contributions separately and sum them together.

5–8 Tutorial Notes TAP Getting Started • CDS-PRM006-EN Trane optimizes the performance of homes and buildings around the world. A business of Trane Technologies the leader in creating and sustaining safe, comfortable and energy efficient environments, Trane offers a broad portfolio of advanced controls and HVAC systems,comprehensive building services, and parts. For more information, visit www.Trane.com.

Trane has a policy of continuous product and product data improvement and reserves the right to change design and specifications without notice.