Operating instructions
1.8 Function and operation modes
The KWL units are equipped with one or more cross counter flow heat exchangers, in which the heat of the extracted
air is recovered and transferred through the plates to the incoming fresh external air, so both air flows remain separa-
ted. Through this procedure more than 80 % of the extract air heat is transferred to the external air. The supply air is led
by the duct system to the primary (supply air needing) areas. The used air is extracted from the secondary areas (like
e.g. social rooms, toilets, showers etc.). It flows back through the ducting to the ventilation unit, transfers the heat and
is discharged by the extract air duct to the atmosphere.
The heat recovery efficiency depends on several factors, which include, among other things, air humidity and the tem-
perature variation of outside air and exhaust air. The fan performance can be adjusted by the controller in scope of deli-
very, various sensors e.g. CO
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- or humidity sensors (accessory) are available on request, with which automatic fan con-
trol is possible (max. 1 sensor can be connected).
The KWL units are equipped with a pre-heater as standard; this prevents the cross counter flow heat exchanger from
freezing at extremely cold outdoor temperatures. The summer bypass is the optimal solution for leading the colder out-
side air into the building in the warmer seasons. The installed filter optimally filters the air, which guarantees a hygienic
unit and simultaneously ensures the service life of the compact unit. A F7 filter is added in the outside air and a F5 filter
is added in exhaust air as standard.
PRO Version:
Types KWL EC .. D PRO have an output of 0-10 V. This can control an external post-heater.
PRO WW Version:
Types KWL EC .. PRO WW are equipped with a hot water post-heater. A WHSH 1100 24 V 0-10 V (accessory) must be
ordered separately.
Constant supply air and/or room air can be introduced with the post-heater.
1.9 Performance data
The unit must be installed correctly and proper supply and exhaust air flow must be ensured to achieve the optimum
performance. Varying from the design and installation requirements and also by incorrect operation can lead to a reduc-
tion in capacity or noise increase. Noise figures are stated in sound power levels LWA in dB(A) (conforms to DIN 45635,
T.1). Sound pressure levels LPA depend on room specific conditions. These conditions may affect the measurement
result on site and vary from the catalogue data.
1.10 Heat systems
The simultaneous use of controlled domestic ventilation (KWL units) and heat systems which depend on room air (tile
oven, gas stove etc.) requires compliance with all applicable regulations. The use of heat systems which depend on
room air are only permitted in state-of-the-art dense apartments with separate combustion air supply; only then are
KWL and heat systems decoupled from each other and operable meeting the demands.
The relevant applicable regulations on the combined use of heat systems, domestic ventilation and extractor hoods
(Federal Association of Chimney Sweeps (ZIV)) must be observed!
– General construction-law requirements
The ventilation unit with heat recovery must not be used simultaneously with fuel-burning heat systems and in residen-
tial units with heat systems which depend on room air, which are connected to multiple exhaust systems. Potential
combustion air ducts and flue gas systems must be capable of being shut off from fuel-burning heat systems for the
proper operation of the ventilation system with a ventilation unit with heat recovery.
The ventilation units with heat recovery must only be installed and operated in rooms with heat systems which depend
on room air, if their flue gas venting is monitored by specific (on-site) safety devices, which shut down ventilation
systems when activated; so that the KWL unit is shut down during the “combustion period”. It will be necessary to
ensure that the use of the domestic ventilation system does not result in a negative pressure larger than 4 Pa in the
residential unit.
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Central ventilation units KWL EC 700/1400/2000 D Pro / WW
Installation and operating instructions
UK
NOTE
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KWL EC .. Pro
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KWL EC .. Pro WW
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