Instructions For Exhaust Air Mode; Diverters And Reductions - BIELMEIER BHG39 User Manual And Installation Instructions

Appropriate use
Clean the extractor hood thoroughly prior to first use. As is the case prior to any other cleaning and servicing, pull the
power plug or disable the circuit breaker to disconnect the unit from power.
Lamps can become very hot when operated. Disconnect the extractor hood from power and allow lightbulbs to
cool down before replacing lightbulbs!
The extractor hood should only be operated with installed lightbulbs. Always switch on the extractor hood
when using a stove top burner. Condensate can form if the hood is switched off, potentially resulting in
corrosion damage on the equipment.
An extractor hood is not a shelf! Do not place objects on the extractor hood..
FIRE HAZARD
You should neither flambee nor work with an open flame under the hood. The flames can be pulled into the filter
by the airflow created when the extractor hood is switched on, in which case the deposits on the grease filter can
ignite. Fire hazard!
The extractor hood must only be installed above fireplaces that can create a fire hazard due to airborne sparks if
the fireplace has a closed, non-removable enclosure and in all cases meets country-specific regulations.
Never leave pots, pans, and fryers unattended when preparing meals with oil and grease, such as French fries.
Oil and grease are easily ignitable!
Regularly cleaning the grease filter and changing the activated carbon filter routinely will mitigate a fire hazard.
The extractor hood must never be operated without a grease filter.
OPERATING MODES – EXHAUST AIR AND RECIRCULATING AIR

Instructions for exhaust air mode

Exhaust air is evacuated to the outside either upward by an air duct or directly through an exterior wall.
NOTE: The exhaust air must be discharged neither through an operational smoke or exhaust chimney nor
through a duct used to ventilate installation rooms for fireplaces. The approval of a competent chimney sweep
specialist must be obtained before the exhaust air can be routed through a non-operational smoke or exhaust
chimney. The regulatory and statutory regulations must be observed when discharging exhaust air (for example
regional construction codes). A telescoping wall sleeve should be used when the exhaust air is routed through
the exterior wall.
The extractor hood achieves its best possible performance with a short, straight exhaust pipe and the largest
possible pipe diameter. If pipe bends cannot be avoided, the radii should be made as large as possible.
In exhaust air mode, it is particularly important that the air volume collected from the room can be made up
unrestricted. The otherwise resulting negative pressure can substantially reduce the extraction performance.
The pressure equalization steps required for this purpose are mandatory in this case. This is either accomplished
with an appropriate makeup air opening with at least the same cross-section as the exhaust air opening or by
using a window switch that only allows the extractor hood to be operated when the
window is opened and/or tilted.
6

Diverters and reductions

Turbulence and backflows are created on reductions and diverters. These can further reduce the backpressure and
increase the noise profile, while also reducing the efficiency of the extractor hood. The use of at least one elbow is
generally unavoidable. However, as a general rule, the fewest possible number of diverters should be used, while re-
ductions and sharp angles should be avoided whenever possible. For instance, the use of two bends with large radii
(> 90°) results in a far lower airflow performance reduction than one 90° elbow. However, the installation must always
take into account that different individual resistances are created depending on the shape of round pipe, hoses
and flat duct, diverters and reductions. These are cumulative and result in a reduction of the airflow volume and in
increased operating noise. We therefore recommend keeping the line as short and straight as possible and using the
lowest possible number of reductions, and taking the location and design of the exhaust airline into consideration
when specifying the airflow volume.
DIN EN 6191 defines a metering arrangement for determining performance, which specifies an exhaust airline
typically used in practice, along with the resulting backpressures. The following pipes are connected to the exhaust
flange of the hood:
- a vertical pipe section with a length of 300 mm
- a 90° elbow
- a horizontal pipe section with a length of 1000 mm
NOTE: Using long, rough exhaust air pies, many pipe bends, or pipe diameters below 150 mm results in a variance
from the optimal air output and in increased noise levels. The exhaust air line must only be routed using pipes and
hoses made from non-combustible materials. The manufacturer of the stove hoods assumes no warranty liability
for claims in connection with the planning and layout of the pipe assembly.
Pipe connections
The diameter of the exhaust pipes should not be below 150 mm.
Round pipes: We recommend an inner diameter of 150 mm, and min. 120 mm.
Flat ducts must have the same inner cross section as round pipes. They should not have sharp changes in direction.
Ø 150 mm approx. 177 cm2
Ø 120 mm approx. 113 cm2
Sealing strips should always be used for deviating pipe diameters.
Diameter of exhaust pipe connection: 150 mm (recommended size)
Attach the exhaust air directly on the air pipe flange and seal appropriately. Smooth out the interface area first
when using aluminum pipes.
GB
7