A handy tool to compare the ATTMA standard to ISO 9972:2012 technical standard.
| ATTMA TSL1: 2021 | ISO 9972:2015 | TM23:2022 | |
|---|---|---|---|
| Intended Building Type | All Buildings | Single-zoned buildings or multi-zone buildings treated as single-zone buildings | Single-zoned buildings or multi-zone buildings treated as single-zone buildings |
| Recommended Test Conditions | <6m/s wind | Wind at Ground <3m/s Wind at Station <6m/s Wind <3 on Beaufort Scale ∆T x Height < 250 mK | Wind at Ground <3m/s Wind at Station <6m/s Wind <3 on Beaufort Scale ∆T x Height < 250 mK |
| Zero Flow Pressure Measurement | 30 second averages; before and after flow measurements | Over 30 seconds at least 10 separate readings; before and after flow measurements | Over 30 seconds at least 10 separate readings; before and after flow measurements |
| Maximum Zero-Flow Pressure (all readings) | < +/- 5 Pascals | < +/- 5 Pascals | < +/- 5 Pascals |
| Maximum Zero-Flow Pressure (all-negative readings) | < -5 Pascals | < -5 Pascals | < -5 Pascals |
| Maximum Zero-Flow Pressure (all-positive readings) | < +5 Pascals | < +5 Pascals | < +5 Pascals |
| Lowest Minimum Test Pressure | 10 Pa; or 5 times the zero-flow pressure | 10 Pa (+/- 3Pa); or 5 times the zero-flow pressure | 10 Pa; or 5 times the zero-flow pressure |
| Lowest Maximum Test Pressure | 50 Pa | 50 Pa; 25 Pa is an acceptable deviation | 50 Pa |
| Minimum spread of test pressures from low to high | 30 Pa (recommended) | n/a | 30 Pa |
| Example Range of Test Pressure Differences | +/- 10 to +/- 90 Pa | n/a | n/a |
| Number of Test Points & Duration | 7 (stable for 30s per reading) | 7 | 7 |
| Maximum Space between Data Points | 10 Pa | approx. 10 Pa | 10 Pa |
| Preferred Test Direction | Both | Both | Both |
| Acceptable Test Direction | Either or Both | Either or Both | Either or Both (Preferred) |
| Acceptable Range: n | 0.50 ≤ n ≤ 1.00 | 0.50 ≤ n ≤ 1.00 | 0.50 ≤ n ≤ 1.00 |
| Acceptable Range: r2 | r² >= 0.98 | r² >= 0.98 | r² >= 0.98 |
| Uniform Building Pressure | Indicates that a check of single-zone conditions should be performed to ensure that the interior pressure differs by no greater than 10% of the measured test pressure from the geometric centre to the top and bottom of the building when it has more than six storey or is greater than 18m in height with 3 or more storey | In tall buildings it is good practice to measure the pressure difference at the top floor level of the building as well as the bottom | For large buildings (greater than three stories or 10 m in height) measured at the lowest and highest floor levels |
| Reporting Metric(s) | Air Permeability Preferred m3.h-1.m-2 @ 50 Pa | Air Permeability Preferred m3.h-1.m-2 @ 50 Pa | Air Permeability Preferred m3.h-1.m-2 @ 50 Pa |
| Equipment Precision | +/- 7% airflow | +/- 7% airflow | +/- 7% airflow |
ATTMA are committed to running impartial schemes. Our Impartiality statement, GDPR data management and data and whilstleblowing policies can be accessed by clicking the links below
ATTMA have a full complaints procedure if you are not happy with ATTMA’s service. Our full complaints procedure can be found here.
Unit 3 Tannery Road Industrial Estate
Tannery Road
High Wycombe
Buckinghamshire
HP13 7EQ
Park House
24 Park Square W
Leeds
LS1 2PW
+44 (0) 1494 358159 | admin@bcta.group
