- HOWATHERM

Transient room ventilation due to intermittent mixed ventilation
Energy-efficient
room ventilation process
System CrossXchange
by HOWATHERM®
Technical information about an energy-efficient room ventilation process for planners,
engineers and plant constructors of ventilation and air-conditioning technology as the basis for
the design, planning and tendering of economical ventilation
The experts for energy-efficient air conditioning technology
System CrossXchange by HOWATHERM®
More - with less
Conventional, continuous operation
Conventional HVAC systems usually consist of
one or more exhaust air
flows and one or more
supply air flow, which
are operated continuously, i.e. stationary in
relation to the room ventilation.
Supply air
Exhaust air
Intermittent operation, phase 1
Supply air
Exhaust air
Room
Intermittent operation, phase 2
Supply air
Exhaust air
Room
Room
Even mixing in the room
In the System CrossXchange by
HOWATHERM®, several inlet and
exhaust air flows are alternately
supplied with air via shutter dampers. Switching between the individual operating conditions of full or
partial load thereby takes place by
switch-over dampers in the individual duct flows. This is carried out
by means of fast-running drives,
whose operation is optimised by a
DDC substation. At the same time,
and despite the alternating operation, the system ensures the provision of both exhaust and inlet air
in the HVAC device, and therefore
a comfortable room climate.
And another plus: conventional
HVAC equipment with the normal
components can also be used for
this intermittent method of operation.
Comparative measurement data of mixed ventilation
Method of operation
Room air speeds
Turbulence levels
Air volume requirement of an auditorium
The System CrossXchange
by HOWATHERM® is a
process for the operation of an HVAC system
that switches between
the individual air supply
and exhaust air flows in
a cycle, thereby supplying the individual flows
with air at alternating
times.
The individual flows are
thereby switched in a
cycle, so that no stationary flow conditions can
develop in the room.
The verification of the effectiveness of the process was carried out by means of example flow
simulations (CFD simulation) by the “TÜV Süd” and in the course of flow trials at the Birkenfeld Environmental Campus (University of Trier).
Major saving in partial-load operation
Effect
A non-steady operation
flow in the room due to
intermittent mixed ventilation improves:
• the effectiveness of
the ventilation
• the air quality and
• the comfort in the
room,
particularly in partialload operation.
With this process, optimum operating conditions can be selected between state of full
load and partial load conditions by means
of determining the flow pulses.
At full air flow, the system is operated conventionally, to avoid over-sizing of the components. But in partial load operation, the
advantages of intermittent operation are
exploited to the full.
Smoke trial – Air distribution with conventional room ventilation
Conventional room ventilation 100% conventional 50%
System CrossXchange by HOWATHERM® for comfortable ventilation of an auditorium
Design advantages
Significant reduction of the components
of the complete system
Homogeneous air distribution
Perfect comfort
Room ventilation applications
Industrial halls
Warehouses
Sales premises
Theatres / cinemas
Event buildings
Multi-purpose halls
Sports facilities
DIY stores
Auditoria
Even air distribution with the System CrossXchange by HOWATHERM
CrossXchange by HOWATHERM® – Left flow active
after the first switch
homogeneous mixed air in the room
System CrossXchange by HOWATHERM®
Hardware COMPONENTS
Air control and
shut-off dampers
Air control and shut-off dampers with technically optimised, swivel-mounted vanes of
hollow aluminium profiles, with adjustment
via rectangular shaft and surrounding frame
enclosure, with the following features:
Max. flow speed 5 m/s
Gears outside the air flow for hygienic
reasons (tendency to soiling / contamination)
Actuation by fast-running setting drive
(max. 4 seconds)
Service life of the dampers and setting
drives is sufficient for at least 5 million
switching cycles, max. 550,000 cycles /
year
System CrossXchange by HOWATHERM
DDC
automation station
The air integrity of the bypass dampers has
been verified by the “TÜV Nord”.
The following values in accordance with DIN
EN 1751 are maintained:
Flap leakage: Class 4
Frame leakage: Class B
Drive for 230 V AC or 24 V AC/DC with fully
available setting range (0 - 10 V),
matched to the required torque of the air
control and shut-off dampers.
Autonomous, native BACnet automation
station with following system functions:
Switching cycles of the inlet and exhaust
dampers of the individual flows
Detection of the volumetric flows of the
inlet and exhaust air equipment by existing volumetric flow measurement system
Detection of CO2 concentration in the
zones to be supplied (optional)
Regulation of the optimum air mass flows
in relation to the load conditions
Regulation of the optimum cycle times
per flow in relation to the load conditions
Performance regulation and air volume
adjustment
Supply air temperature regulation
(optional)
Error and operating messages of the
damper drives
Connection of external systems via additional inputs and outputs
External set value specification 0-10 V
Fully-wired separate switch cabinet with
cabling of all control, regulation and drive
components installed in the unit.
for switching off device cables, fuses and
all necessary components for motor actuation, such as contactors, protection switches
etc., terminal rail for receiving the external
measurement and control signals
Fast-running setting drive,
switch and regulation device
DDC Controller unit
(optimisation)
Freely programmable DDC.
Native communication BACnet, ANSI /
ASHRAE Standard 135-2001 (BACnet),
EN 13321. All field equipment and switch
cabinets for on-site installation are included.
Operating unit
Controller
Intuitive local operation with rotary/pushbutton switch and LVD clear display, integrated into the front of the switch cabinet
(with RS232 interface, 38.4 kBit/s, systemwide at communications bus).
Free programmability by graphic programming language
Universal inputs freely configurable by
software
Digital inputs for potential-free messages
or counter values
Digital or analogue universal outputs,
operating hours counter
Timer programme
Digital outputs 250 V, max. 2 A Regulation and
drive components
Terminals for the main power supply, motor
and control cables, main/repair switches
Reference
Communication: autonomous or in
system assembly
Event-orientated data
Alarm and message processing
Automatic power restoration
Historical data memory
Unlosable DDC programmes
Battery buffering
Flash-ROM, real-time processing and
multi-task / user
32 Bit, 2-processor system, 1,5 MB,
programme memory
Regulator settings protected against
loss by feeding voltage
Secure regulator parameter set at
regulator level
Secure regulator parameter set on
service tool
Room ventilation system for the Soest Technical College with 10,000 m3/h air performance
The advantages
The System CrossXchange by HOWATHERM®
reduces the required air exchange, and therefore
saves heat and electrical energy
reduces the investment costs, since the system
can be designed with smaller dimensions
s ubstantially improves the air quality through
pulse ventilation
creates greater comfort in the room
Patented as “Process for ventilation of a room” under number DE 10 2009 009 109
with the German Patent Office.
HOWATHERM Klimatechnik GmbH
Keiperweg 11-15
55767 Brücken / Germany
Telephone +49 6782 99 99 - 0
Telefax +49 6782 99 99 - 10
Direct Call 0700HOWATHERM
www.howatherm.de
[email protected]
The experts for energy-efficient air conditioning technology
Ed. 02/2015
Development: eka;MedienStudio, Frankfurt, Germany
Design: Atelier Schiller-Krenz, Frankfurt, Germany
Printing: HBO-Druck, Einhausen, Germany
Excerpt from our references:
Aachener Münchener Versicherungen,
Köln • Aachener Quarzglas, Aachen •
Archiv Dommusik, Würzburg • B. Braun
AG, Melsungen • BASF Coatings AG,
Münster • Bayer Schering GmbH, Berlin
• Bayer Schering Pharma AG, Wuppertal
• BIOLAC GmbH & Co. KG, Harbarnsen •
BMW, Düsseldorf • BNP Paribas, Luxembourg • Boehringer Ingelheim Pharma
GmbH & Co. KG, Ingelheim • Burger
King, Ramstein • Carl Zeiss Jena GmbH,
Jena • Centre Hospitalier Emile Mayrisch, Niedercon Luxembourg • Centre
Hospitalier Luxembourg, Luxembourg •
CERN Conseil Européen pour la Recherche Nucléaire, Genf Schweiz • Chocoladenfabriken Lindt & Sprüngli GmbH,
Aachen • CNSC Centre National Sportif
et Culturel D´Coque, Kirchberg Luxembourg • Cognis, Düsseldorf • Cour des
Comptes Europäischer Rechnungshof,
Kirchberg Luxembourg • Covance Laboratories GmbH, Münster • Crucell GMP,
Leiden Niederlande • Decoma Exterior
Systems GmbH, Obertshausen • Degussa
AG, Wesseling • Die Fernsehwerft GmbH,
Berlin • 3M Deutschland GmbH, Kamen
• AG der Dillinger Hüttenwerke, Dillingen
• DLR Deutsches Zentrum für Luft- und
Raumfahrt, Hardthausen-Lampoldshausen • Dorint Hotel, Köln • Dr. August
Oetker Nahrungsmittel KG, Wittlich • Dr.
Kade Pharmazeutische Fabrik GmbH,
Konstanz • Evonik Power Saar GmbH,
Völklingen • Fachhochschule Weihenstephan, Freising • Ford GmbH, Saarlouis •
Fraunhofer Institut für Grenzflächen- und
Bioverfahrenstechnik IGB, Stuttgart • Fresenius SE, Biebesheim • Geschäftshaus
Louis Vuitton, Luxembourg • Goodyear
Dunlop Tires Germany GmbH, Riesa •
Grünenthal GmbH, Aachen • Helios Klinik, Berlin Buch • Henkel AG & Co. KGaA,
Düsseldorf • Henning von Tresckow Kaserne, Geltow • Hermes Pharma GmbH,
Wolfsberg Österreich • Hexal Pharma
GmbH, Radebeul • Hilton Hotel International Germany GmbH, München • Hilton Hotel International Germany GmbH,
Dresden • Hirschvogel Umformtechnik
GmbH, Denklingen • IBM, Mainz • IFA
Leipnitz-Institut für Arbeitsforschung
der TU, Dortmund • Johannes Gutenberg Universität, Mainz • Kernkraftwerk
Krümmel, Gheesthacht • Kerrygold Butterverarbeitungswerk, Neukirchen-Vluyn
• KKW Kernkraftwerk, Mülheim-Kärlich
• Klinikum der Universität, Heidelberg •
Knorr Unilever Deutschland GmbH, Bremen
• Kunstsammlung Nordrhein-Westfalen,
Düsseldorf • Ludwig Schokolade GmbH
& Co. KG, Saarlouis • MAN Ferrostaal AG,
Essen • Maredo Restaurants Holding GmbH,