Roof fans - Types and design features
Wolter roof fan units are suitable for mounting on different roof types. There are two versions available:
Type RH with horizontal discharge for the exhaust of
mildly polluted air 
Type RV with vertical discharge for the exhaust of
more heavily polluted air

Casing
RH up to size 500, the cowl is made of salt-water proof
aluminium, from size 560 onwards, the cowl is manufactured
from galvanised sheet steel
RV housing is made of salt-water proof aluminium
RVS with built-in sound attenuation hood

Impeller
The backward-curved impellers are mounted directly onto the rotor of the external rotor motors.

The motorised
 

Motor
Speed controllable external rotor motor, protection class IP44 (up to size 310L) or IP54 (from size 355), moisture-proof impregnation, thermal contacts mounted in motor winding.

Electrical connection
The motors are connected to a terminal box of protection class IP54, easily accessible after disassembly of the cowl.

Installation
All fans are delivered ready for installation and are packed in separate boxes or crates. We recommend the use of matching Wolter roof sockets. If other roof sockets are used, dimensions given in our catalogue should be followed to achieve proper sealing and avoid air-leakage.

Fan performance curves
The performance curves for these roof fans have been tested according to DIN 24 163. The curves indicate the static pressure increase .pst (static, free outlet) as a function of the volume flow. The reference air density is 1,2 kg/m³.

Sound levels
The sound data was measured according to DIN 45 635, part 38. The figures shown in the performance curves are the A-weighted sound power levels in dB(A). They are equal to the free outlet sound power level. The catalogue data is valid for RH-type fans. reduce listed noise levels by 2 dB(A). The free inlet sound power level can be calculated

Sound reduction
Socket silencer SD
Insulated sound attenuation cowl LVS A socket silencer can be used instead of the flat roof socket for mounting the fan. It reduces the sound propagation on the suction side. When a socket silencer is used, additional pressure loss has to be taken into account. These can be found in the following diagram.
Insulated sound attenuation cowl LVS
In order to reduce the sound emissions radiated from the roof fan, the use of a RVS attenuation cowl is recommended. Compared to the non-attenuated roof fan cowl (RV) Insulated sound attenuation cowl LVS the RVS cowl has slightly higher pressure losses.

 

 

 

 

 

 

 

 

 

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