Application
Special characteristics
Nominal sizes
Variants
Construction
Parts and characteristics
Construction features
Materials and surfaces
Mineral wool
Standards and guidelines
Maintenance
Functional description
External weather louvres are externally mounted air transfer devices for the fresh air and exhaust air of air conditioning systems. They are installed in external walls and façades. Their narrowly arranged blades give good protection against the direct ingress of rain as well as against leaves and birds.
Under certain unfavourable conditions, such as heavy rain, and depending on the airflow velocity it might happen that slight quantities of water enter together with the air.
This is why the airflow velocity in fresh air openings should not exceed 2 – 2.5 m/s.
Nominal sizes | 300 × 450 to 1800 × 2250 mm |
Width subdivided | Up to 3600 mm |
Height subdivided | Up to 4500 mm |
Volume flow rate range (undivided construction) | 120 – 9360 l/s or 432 – 33696 m³/h at max. 2.5 m/s |
Insertion loss
NL | 3 | 4 | 7 | 8 | 13 | 15 | 13 | 15 |
NL-H | 3 | 6 | 9 | 16 | 21 | 24 | 24 | 30 |
Sound reduction index
NL | – | 6 | 6 | 9 | 13 | 14 | – | 12 |
NL-H | – | 7 | 9 | 16 | 25 | 27 | – | 21 |
Quick sizing tables provide a good overview of the volume flow rates with an airflow velocity of 2.5 m/s. Values for intermediate widths can be interpolated. Precise intermediate values and volume flow rates for other airflow velocities can be calculated with our Easy Product Finder design programme.
The sound power levels LWA apply to external weather louvres with a flow cross section of 1 m².
NL, width 300 – 1050 mm, volume flow rate at max. 2.5 m/s
450 | 120 | 432 | 180 | 648 | 240 | 864 | 300 | 1080 | 360 | 1296 | 420 | 1512 |
600 | 240 | 864 | 360 | 1296 | 480 | 1728 | 600 | 2160 | 720 | 2592 | 840 | 3024 |
750 | 360 | 1296 | 540 | 1944 | 720 | 2592 | 900 | 3240 | 1080 | 3888 | 1260 | 4536 |
900 | 480 | 1728 | 720 | 2592 | 960 | 3456 | 1200 | 4320 | 1440 | 5184 | 1680 | 6048 |
1050 | 600 | 2160 | 900 | 3240 | 1200 | 4320 | 1500 | 5400 | 1800 | 6480 | 2100 | 7560 |
1200 | 720 | 2592 | 1080 | 3888 | 1440 | 5184 | 1800 | 6480 | 2160 | 7776 | 2520 | 9072 |
1350 | 840 | 3024 | 1260 | 4536 | 1680 | 6048 | 2100 | 7560 | 2520 | 9072 | 2940 | 10584 |
1500 | 960 | 3456 | 1440 | 5184 | 1920 | 6912 | 2400 | 8640 | 2880 | 10368 | 3360 | 12096 |
1650 | 1080 | 3888 | 1620 | 5832 | 2160 | 7776 | 2700 | 9720 | 3240 | 11664 | 3780 | 13608 |
1800 | 1200 | 4320 | 1800 | 6480 | 2400 | 8640 | 3000 | 10800 | 3600 | 12960 | 4200 | 15120 |
1950 | 1320 | 4752 | 1980 | 7128 | 2640 | 9504 | 3300 | 11880 | 3960 | 14256 | 4620 | 16632 |
2100 | 1440 | 5184 | 2160 | 7776 | 2880 | 10368 | 3600 | 12960 | 4320 | 15552 | 5040 | 18144 |
2250 | 1560 | 5616 | 2340 | 8424 | 3120 | 11232 | 3900 | 14040 | 4680 | 16848 | 5460 | 19656 |
NL, width 1200 – 1800 mm, volume flow rate at max. 2.5 m/s
450 | 480 | 1728 | 540 | 1944 | 600 | 2160 | 660 | 2376 | 720 | 2592 |
600 | 960 | 3456 | 1080 | 3888 | 1200 | 4320 | 1320 | 4752 | 1440 | 5184 |
750 | 1440 | 5184 | 1620 | 5832 | 1800 | 6480 | 1980 | 7128 | 2160 | 7776 |
900 | 1920 | 6912 | 2160 | 7776 | 2400 | 8640 | 2640 | 9504 | 2880 | 10368 |
1050 | 2400 | 8640 | 2700 | 9720 | 3000 | 10800 | 3300 | 11880 | 3600 | 12960 |
1200 | 2880 | 10368 | 3240 | 11664 | 3600 | 12960 | 3960 | 14256 | 4320 | 15552 |
1350 | 3360 | 12096 | 3780 | 13608 | 4200 | 15120 | 4620 | 16632 | 5040 | 18144 |
1500 | 3840 | 13824 | 4320 | 15552 | 4800 | 17280 | 5280 | 19008 | 5760 | 20736 |
1650 | 4320 | 15552 | 4860 | 17496 | 5400 | 19440 | 5940 | 21384 | 6480 | 23328 |
1800 | 4800 | 17280 | 5400 | 19440 | 6000 | 21600 | 6600 | 23760 | 7200 | 25920 |
1950 | 5280 | 19008 | 5940 | 21384 | 6600 | 23760 | 7260 | 26136 | 7920 | 28512 |
2100 | 5760 | 20736 | 6480 | 23328 | 7200 | 25920 | 7920 | 28512 | 8640 | 31104 |
2250 | 6240 | 22464 | 7020 | 25272 | 7800 | 28080 | 8580 | 30888 | 9360 | 33696 |
NL, differential pressure and sound power level
1.5 | 0.2 – 0.4 | 2 | <15 | 2 | <15 | 2 | <15 | 1 | <15 |
2 | 0.2 – 0.6 | 4 | <15 | 4 | <15 | 4 | <15 | 4 | <15 |
4 | 0.4 – 1.2 | 18 | 32 | 14 | 28 | 18 | 29 | 14 | 27 |
6 | 0.7 – 1.7 | 40 | 44 | 30 | 40 | 40 | 41 | 28 | 39 |
8 | 0.9 – 2.3 | 70 | 52 | 50 | 48 | 65 | 49 | 50 | 47 |
10 | 1.1 – 2.9 | 110 | 58 | 80 | 54 | 105 | 55 | 75 | 53 |
NL-H, Differential pressure and sound power level
1 | 0.1 – 0.3 | 2 | <15 | 2 | <15 | 2 | <15 | 2 | <15 |
2 | 0.2 – 0.6 | 8 | 26 | 6 | 19 | 6 | 18 | 6 | 18 |
3 | 0.3 – 0.9 | 16 | 37 | 12 | 30 | 12 | 29 | 12 | 29 |
4 | 0.4 – 1.2 | 26 | 45 | 20 | 38 | 20 | 37 | 20 | 37 |
5 | 0.6 – 1.5 | 40 | 52 | 30 | 45 | 30 | 44 | 30 | 44 |
7 | 0.8 – 2.0 | 80 | 61 | 65 | 54 | 60 | 53 | 60 | 53 |
Rectangular acoustic louvres as a protection of air conditioning systems against the direct ingress of rain, leaves and birds into fresh air and exhaust air openings.
Ready-to-install component which consists of a border, aerofoil rain defence blades, and a wire mesh at the rear.
Insertion loss measured according to ISO 7235, sound reduction index measured according to EN ISO 10140-2.
Special characteristics
Materials and surfaces
Mineral wool
Construction
Technical data
Sizing data
Air-regenerated noise
Weighted sound reduction index
This specification text describes the general properties of the product. Texts for variants can be generated with our Easy Product Finder design programme.
Order example: NL–H–S/1050×750
Acoustic performance | High |
Material | Galvanised steel |
Nominal size | 1050×750 mm |
Surface | Standard construction |
NL
Variant
Parts and characteristics
Construction features
Materials and surfaces
Mineral wool
NL-H
Variant
Parts and characteristics
Construction features
Materials and surfaces
Mineral wool
NL-D
Variant
Parts and characteristics
Construction features
Materials and surfaces
Materials
Casing and blades | S | Galvanised sheet steel | |
Casing and blades | A | Aluminium | |
Perforated sheet metal to retain absorption material | – | Galvanised sheet steel | Only NL, NL-H |
Bird mesh | – | Galvanised steel | Only NL, NL-H |
Absorption material | – | Mineral wool | Only NL, NL-H |
Surfaces
Casing and blades | – | Untreated | |
Casing and blades | P1-RAL ... | Powder-coated, RAL colour ... CLASSIC |
NL-S, Weight
450 | 7 | 10 | 13 | 16 | 19 | 23 | 26 | 29 | 32 | 36 | 39 |
600 | 9 | 13 | 17 | 22 | 26 | 30 | 35 | 39 | 43 | 48 | 52 |
750 | 11 | 16 | 22 | 27 | 32 | 38 | 43 | 49 | 54 | 59 | 65 |
900 | 13 | 19 | 26 | 32 | 39 | 45 | 52 | 58 | 65 | 71 | 78 |
1050 | 15 | 23 | 30 | 38 | 45 | 53 | 61 | 68 | 76 | 83 | 91 |
1200 | 17 | 26 | 35 | 43 | 52 | 61 | 69 | 78 | 86 | 95 | 104 |
1350 | 19 | 29 | 39 | 49 | 58 | 68 | 78 | 88 | 97 | 107 | 117 |
1500 | 22 | 32 | 43 | 54 | 65 | 76 | 86 | 97 | 108 | 119 | 130 |
1650 | 24 | 36 | 48 | 59 | 71 | 83 | 95 | 107 | 119 | 131 | 143 |
1800 | 26 | 39 | 52 | 65 | 78 | 91 | 104 | 117 | 130 | 143 | 156 |
1950 | 28 | 42 | 56 | 70 | 84 | 98 | 112 | 126 | 140 | 154 | 169 |
2100 | 30 | 45 | 61 | 76 | 91 | 106 | 121 | 136 | 151 | 166 | 181 |
2250 | 32 | 49 | 65 | 81 | 97 | 113 | 130 | 146 | 162 | 178 | 194 |
NL-A, weight
450 | 5 | 7 | 10 | 12 | 14 | 17 | 19 | 21 | 24 | 26 | 28 |
600 | 6 | 10 | 13 | 16 | 19 | 22 | 25 | 28 | 32 | 35 | 38 |
750 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 35 | 39 | 43 | 47 |
900 | 10 | 14 | 19 | 24 | 28 | 33 | 38 | 43 | 47 | 52 | 57 |
1050 | 11 | 17 | 22 | 28 | 33 | 39 | 44 | 50 | 55 | 61 | 66 |
1200 | 13 | 19 | 25 | 32 | 38 | 44 | 50 | 57 | 63 | 69 | 76 |
1350 | 14 | 21 | 28 | 35 | 43 | 50 | 57 | 64 | 71 | 78 | 85 |
1500 | 16 | 24 | 32 | 39 | 47 | 55 | 63 | 71 | 79 | 87 | 95 |
1650 | 17 | 26 | 35 | 43 | 52 | 61 | 69 | 78 | 87 | 95 | 104 |
1800 | 19 | 28 | 38 | 47 | 57 | 66 | 76 | 85 | 95 | 104 | 113 |
1950 | 21 | 31 | 41 | 51 | 61 | 72 | 82 | 92 | 102 | 113 | 123 |
2100 | 22 | 33 | 44 | 55 | 66 | 77 | 88 | 99 | 110 | 121 | 132 |
2250 | 24 | 35 | 47 | 59 | 71 | 83 | 95 | 106 | 118 | 130 | 142 |
NL-H-S, weight
450 | 13 | 19 | 26 | 32 | 39 | 45 | 52 | 58 | 65 | 71 | 78 |
600 | 17 | 26 | 35 | 43 | 52 | 61 | 69 | 78 | 86 | 95 | 104 |
750 | 22 | 32 | 43 | 54 | 65 | 76 | 86 | 97 | 108 | 119 | 130 |
900 | 26 | 39 | 52 | 65 | 78 | 91 | 104 | 117 | 130 | 143 | 156 |
1050 | 30 | 45 | 61 | 76 | 91 | 106 | 121 | 136 | 151 | 166 | 181 |
1200 | 35 | 52 | 69 | 86 | 104 | 121 | 138 | 156 | 173 | 190 | 207 |
1350 | 39 | 58 | 78 | 97 | 117 | 136 | 156 | 175 | 194 | 214 | 233 |
1500 | 43 | 65 | 86 | 108 | 130 | 151 | 173 | 194 | 216 | 238 | 259 |
1650 | 48 | 71 | 95 | 119 | 143 | 166 | 190 | 214 | 238 | 261 | 285 |
1800 | 52 | 78 | 104 | 130 | 156 | 181 | 207 | 233 | 259 | 285 | 311 |
1950 | 56 | 84 | 112 | 140 | 169 | 197 | 225 | 253 | 281 | 309 | 337 |
2100 | 61 | 91 | 121 | 151 | 181 | 212 | 242 | 272 | 302 | 333 | 363 |
2250 | 65 | 97 | 130 | 162 | 194 | 227 | 259 | 292 | 324 | 356 | 389 |
NL-H-A, weight
450 | 10 | 14 | 19 | 24 | 28 | 33 | 38 | 43 | 47 | 52 | 57 |
600 | 13 | 19 | 25 | 32 | 38 | 44 | 50 | 57 | 63 | 69 | 76 |
750 | 16 | 24 | 32 | 39 | 47 | 55 | 63 | 71 | 79 | 87 | 95 |
900 | 19 | 28 | 38 | 47 | 57 | 66 | 76 | 85 | 95 | 104 | 113 |
1050 | 22 | 33 | 44 | 55 | 66 | 77 | 88 | 99 | 110 | 121 | 132 |
1200 | 25 | 38 | 50 | 63 | 76 | 88 | 101 | 113 | 126 | 139 | 151 |
1350 | 28 | 43 | 57 | 71 | 85 | 99 | 113 | 128 | 142 | 156 | 170 |
1500 | 32 | 47 | 63 | 79 | 95 | 110 | 126 | 142 | 158 | 173 | 189 |
1650 | 35 | 52 | 69 | 87 | 104 | 121 | 139 | 156 | 173 | 191 | 208 |
1800 | 38 | 57 | 76 | 95 | 113 | 132 | 151 | 170 | 189 | 208 | 227 |
1950 | 41 | 61 | 82 | 102 | 123 | 143 | 164 | 184 | 205 | 225 | 246 |
2100 | 44 | 66 | 88 | 110 | 132 | 154 | 176 | 199 | 221 | 243 | 265 |
2250 | 47 | 71 | 95 | 118 | 142 | 165 | 189 | 213 | 236 | 260 | 284 |
NL-D-S, weight
450 | 3 | 5 | 7 | 8 | 10 | 11 | 13 | 15 | 16 | 18 | 19 |
600 | 4 | 7 | 9 | 11 | 13 | 15 | 17 | 19 | 22 | 24 | 26 |
750 | 5 | 8 | 11 | 14 | 16 | 19 | 22 | 24 | 27 | 30 | 32 |
900 | 7 | 10 | 13 | 16 | 19 | 23 | 26 | 29 | 32 | 36 | 39 |
1050 | 8 | 11 | 15 | 19 | 23 | 27 | 30 | 34 | 38 | 42 | 45 |
1200 | 9 | 13 | 17 | 22 | 26 | 30 | 35 | 39 | 43 | 48 | 52 |
1350 | 10 | 15 | 19 | 24 | 29 | 34 | 39 | 44 | 49 | 54 | 58 |
1500 | 11 | 16 | 22 | 27 | 32 | 38 | 43 | 49 | 54 | 59 | 65 |
1650 | 12 | 18 | 24 | 30 | 36 | 42 | 48 | 54 | 59 | 65 | 71 |
1800 | 13 | 19 | 26 | 32 | 39 | 45 | 52 | 58 | 65 | 71 | 78 |
1950 | 14 | 21 | 28 | 35 | 42 | 49 | 56 | 63 | 70 | 77 | 84 |
2100 | 15 | 23 | 30 | 38 | 45 | 53 | 61 | 68 | 76 | 83 | 91 |
2250 | 16 | 24 | 32 | 41 | 49 | 57 | 65 | 73 | 81 | 89 | 97 |
NL-D-A, weight
450 | 2 | 4 | 5 | 6 | 7 | 8 | 10 | 11 | 12 | 13 | 14 |
600 | 3 | 5 | 6 | 8 | 10 | 11 | 13 | 14 | 16 | 17 | 19 |
750 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 |
900 | 5 | 7 | 10 | 12 | 14 | 17 | 19 | 21 | 24 | 26 | 28 |
1050 | 6 | 8 | 11 | 14 | 17 | 19 | 22 | 25 | 28 | 30 | 33 |
1200 | 6 | 10 | 13 | 16 | 19 | 22 | 25 | 28 | 32 | 35 | 38 |
1350 | 7 | 11 | 14 | 18 | 21 | 25 | 28 | 32 | 35 | 39 | 43 |
1500 | 8 | 12 | 16 | 20 | 24 | 28 | 32 | 35 | 39 | 43 | 47 |
1650 | 9 | 13 | 17 | 22 | 26 | 30 | 35 | 39 | 43 | 48 | 52 |
1800 | 10 | 14 | 19 | 24 | 28 | 33 | 38 | 43 | 47 | 52 | 57 |
1950 | 10 | 15 | 21 | 26 | 31 | 36 | 41 | 46 | 51 | 56 | 61 |
2100 | 11 | 17 | 22 | 28 | 33 | 39 | 44 | 50 | 55 | 61 | 66 |
2250 | 12 | 18 | 24 | 30 | 35 | 41 | 47 | 53 | 59 | 65 | 71 |
Installation and commissioning
Installation information
Nomenclature
LWA [dB(A)]
A-weighted sound power level of air-regenerated noise for the louvre
A [m²]
Upstream cross section
v [m/s]
Airflow velocity based on the upstream cross section
vt [m/s]
Airflow velocity based on the upstream cross section (type NL)
V [m³/h] and [l/s]
Volume flow rate
Δpt [Pa]
Total differential pressure
All sound power levels are based on 1 pW.
De [dB]
Insertion loss
Measured with sound transmission from inside to outside
R [dB]
Sound reduction index
RW [dB]
Weighted sound reduction index
Measured with sound transmission from inside to outside
Principal dimensions
B [mm]
Duct width
B₁ [mm]
Duct width for subdivided louvres
H [mm]
Duct height
H₁ [mm]
Duct height for subdivided louvres
n [ ]
Number of flange screw holes
m [kg]
Weight
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We are here for you
Please specify your message and type of request.
Tel.: +43 1 250 43-0 | Fax: +43 1 250 43 34
Contact
Thank you for your message!
Your message is send and will be processed shortly.
Our department for Service-Requests will contact you asap.
For general question regarding products or services you can also call:
Tel.: +43 1 250 43-0| Fax: +43 1 250 43 34