Standard Calculations - Moosevellous/Trace GitHub Wiki
Standard Calculation Sheets
These sheets are set up to calculate common acoustic problems. The ‘Standard Calculation’ button on the ribbon scans the directory (Trace/Standard Calc Sheets) and populates a list in a form. The user selects from the list and is prompted to save a copy, which is date stamped by default.
As with Blank Calculation Sheets, the Standard Calculation Sheets are laid out to fit a on a page when printed. Not all lines of the calculation are displayed in the final presented sheet, but should be sufficient for a review.
Table 1 of the main Trace Page shows a list of the Sheets that have been developed to date. Other sheets can be developed and shared within an organisation by simply copying them into the appropriate folder, however sharing calculation sheets to the entire development pool for common acoustic calculations is strongly encouraged.
The list of Standard Calculation Sheets on this page, or on the main Trace page, may not be up to date.
| Code | Name | Description | Latest Version (date of editing this page) |
|---|---|---|---|
| BA | Barrier Attenuation | Implements Maekawa's formula to predict barrier insertion loss | 1.3 |
| CT | Cross Talk | Calculates cross talk paths between rooms | 0.2 |
| FBI | Façade Break In | Calculates internal noise level from external source - multiple paths | 0.2 |
| GLZ | Noise Ingress Glazing | Predicts internal noise level of external noise source through glazing in one-third octave bands | 1.4 |
| LG | Logger Grapher | Presents ARL316 logger data | 0.14 |
| N1L | SEPP N-1 Limits | "Determines Noise Limits under State Environment Protection Policy No N-1 - Control of Noise from commerce, industry and trade" | 1.2 |
| NR1L | NIRV Limits | Determines Recommended Maximum Noise Levels (RMNLs) under EPA Publication 1411 - Noise in Regional Victoria | 1.1 |
| P2W | SWL to SPL Conversion | Converts SPL to SWL for up to four sources. Converts SWL to SPL based on RT of room | 1.1 |
| R2R | Room to Room Transmission | "Predicts noise levels in a room, transmitted through a partition from another room" | 1.3 |
| RN | Rain Noise | Predicts rain noise based on roofing system. | 0.5 |
| RT | RT Calculation | Estimates Reverberation Time using 3 methods based on room geometry and finishes. | 1.9 |
| SIA | Sound Insulation - Airborne | Calculates Dw and DnTw for measured wall/floor systems | 1.9 |
| SII | Sound Insulation - Impact | Calculates LnTw for floor/ceiling systems | 1.0 |
| SSI | Simple Spring Isolation Calculator | Checks transmissibility of springs - no damping | 1.1 |
| JIS | SPL to SWL (JIS method) | Converts FCU SPLs to SWL reverse engineered paths and some assumptions (ROUGH) | 1.3 |
Barrier Attenuation
Cross Talk
Façade Break In
Noise Ingress Glazing
Logger Grapher
SEPP N-1 Limits
NIRV Limits
SWL to SPL Conversion
Room to Room Transmission
Rain Noise
RT Calculation
Provides a method of calculating reverberation time (RT) in octave bands for a rectangular room. Calculation by Sabine, Eyring-Norris and Fitzroy methods are given. The standard sheet opens with the following tabs:
- RT - where you input all your stuff and get answers
- Product Data - contains octave band absorption values for surface materials. Each material has a unique integer identifier used for easy entry on the RT page
- AS2107_2016 - Recommended RT values from Australian Standard 2107. If you are not in Australia, well you probably can't come till next year.
- INFO - explains how to calculate according to Eyring-Norris and Fitzroy methods.
- CONVERT - converts 1/3 octave absorption values to octave band values.
Procedure
On the RT tab there are many yellow cells. These can mostly be autofilled. The general procedure is:
- Enter Length, Width and Height. If your room is a box, then the automatically calculated values for volume and floor, ceiling and wall surface areas are already correct.
- In "RT Criterion" choose AS2107 or "manual" if your prefer to
- Choose AS2107 Category (e.g. Office or Educational Building)
- Choose AS2107 Room Type (e.g. Cafeteria) - This will fill in minimum and maximum Target RT. These will be displayed on the graph at the bottom of the page. (If the target RT is not a range buy an inequality, e.g. <1.0 secs, the graphing won't be done correctly).
- For each Surface, choose a surface material. This is done by scanning the "Product Data" tab for something you like. For example if your floor is concrete, you'll find it has Absorption element number 98. So enter 98 in the Element Number cell for the floor. If your surface material is not already in the data base, add it on a new row and give it its own element number. You could, instead, just overwrite the numbers on the calculation sheet, but it is preferable to make a new material on the Product Data Sheet.
- The sheet has two further rows for wall and ceiling treatment. If you say there is an area of x square metres of treatment on the ceiling, this area will be subtracted from the Ceiling area on Line 6 of the calc. Wall treatment area is subtracted from the Line 7 wall (marked Transvers by default)
- Look at the answers and write your report.