The industry standard for weather testing of louvres in the UK was developed by BSRIA (Building Services Research and Information Association) and HEVAC (Heating, Ventilation and Air Conditioning Manufacturers Association) and was adopted in 2001 as a British and European Standard: BS EN 13030:2001.
BS EN 13030:2001 Tests Louvres in 3 key performance areas:
- Effectiveness: The ability to prevent rain penetrating the louvre
- Discharge Loss Coefficient: The airflow characteristic of the louvre, the higher the coefficient, the less resistant the louvre: allowing air to pass more freely
- Overall Performance: This is determined by multiplying the effectiveness by the coefficient. This should not be used as the sole determining factor when choosing louvres as it can mask poor weather performance on a louvre with good airflow.
We are one of the few manufacturers in the world to have it’s own HEVAC test rig to ensure all our louvres can be fully tested. The image below shows what that looks like:
The HEVAC/BSRIA test method enables specifiers to relate one manufacturers’ performance against another at set benchmarks, helping to make specification easier. The tables below outline those benchmarks.
Louvre Effectiveness (Penetration Class)
| Class | Effectiveness (PC) | Maximum allowable penetration of rain l/h.m² |
|---|---|---|
| A | 1 to 0.99 | 0.75 |
| B | 0.989 to 0.95 | 3.75 |
| C | 0.949 to 0.80 | 15 |
| D | Below 0.8 | Greater than 15 |
Airflow Class (Discharge Loss Coefficient)
| Airflow Class | Discharge Loss Coefficient (DLC) | Rating |
|---|---|---|
| 1 | 0.4 and Above | Excellent |
| 2 | 0.3 to 0.399 | Very Good |
| 3 | 0.2 to 0.299 | Good |
| 4 | 0.199 and below | Fair |
Below you can see tables for some of our Louvre models, to show their performance during this testing at various ventilation rates:
RSH-5700
| Core Ventilation Rate | 0.0 | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 |
|---|---|---|---|---|---|---|---|---|
| Rain Defence Class | A | A | A | A | A | A | A | B |
| Effectiveness Ratio | 100% | 100% | 100% | 99.8% | 99.9% | 99.8% | 99.9% | 98.7% |
| Airflow Class | 3 | Airflow Coefficient Ce (Intake) | 0.289 | |||||
RS-5605
| Core Ventilation Rate | 0.0 | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 |
|---|---|---|---|---|---|---|---|---|
| Rain Defence Class | A | A | A | A | A | A | A | B |
| Effectiveness Ratio | 99.8% | 99.9% | 99.9% | 99.9% | 100% | 100% | 100% | 100% |
| Airflow Class | 1 | Airflow Coefficient Ce (Intake) | 0.466 | |||||
A-3105
| Core Ventilation Rate (m/s) | 0.0 | 0.5 | 1.0 | 1.5 | 2.0 | 2.5 | 3.0 | 3.5 |
|---|---|---|---|---|---|---|---|---|
| Rain Defence Class: | C | C | C | C | C | C | C | D |
| Effectiveness Ratio: | 91.5 | 90.0 | 88.3 | 87.0 | 84.7 | 82.6 | 80.1 | 53.5 |
| Airflow Class: | 2 | Airflow Coefficient Ce (Intake): | 0.391 | |||||
