Twin Wheel Integrated SystemEnergy efficient humidity control

Maximized climate control with minimized energy costs

The integrated system utilizes Fläkt Woods unique

Twin-Wheel™ AHU low-energy technology and high

efficiency free-cooling chillers, combined with a precisely

matched selection of chilled beams and an option of

individual room monitoring of temperature and humidity.

At the heart of the system lies advanced hygroscopic

wheel technology, perfectly matched to the low humidity

requirements of the chilled beams, eliminating the risk

of condensation whilst achieving class-leading levels of

energy recovery.

Air quality

Today we demand a comfortable environ-ment when inside a building. One important parameter for a good indoor environment is the air quality. Good indoor air quality in turn is a combination of factors like oxygen level, humidity, absence of odor and pollution - and obviously the right temperature.

Energy costs

Cooling and heating processes typically demand high levels of energy supply. In modern buildings air treatment is often the biggest consumer of power. This fact, together with constantly increasing global energy prices, call for systems optimized for best overall efficiency. At Fläkt Woods we combine our

experience with advanced technology to achieve intelligent system solutions. They are sound investments providing a short pay-back and dramatic savings in the long run.

Environment

The environment is also a winner with our solutions. For nature, regardless of energy source, the least harmful kilowatt of energy is the one saved and never produced.

Controlled humidity

Control over the humidity content of the air is one factor to reach good indoor air quality. Humidity control is also essential for use of ‘chilled beams’, an air cooling technique with good efficiency and high levels of comfort.

Twin Wheel IntegratedSystem Components:

• Twin Wheel AHU with fully integrated controls

• Free-Cooling Chiller

• Chilled Beams with optional room sensors

• Room Controllers

Integrated advantages

Fläkt Woods has designed the Twin Wheel system to provide advanced cooling and humidity control versus other solutions on the market. The purpose is to produce cool and dry air while lowering the cost for these processes compared to conventional systems.

System benefits:

• Chiller configured for mini-mum energy consumption

• Low humidity supply air matched to requirements of chilled beams

• Reduced electrical load for plant, providing lower cost connections

• High efficiency recovery minimises heating energy

• Optional Heat Pump system for winter operation

• Occupancy control provides further energy savings

Guaranteed performance:

• Set point humidity control

• Condensation-free beams

• Controlled velocity within occupied zone

• Guaranteed levels of noise generation

• Temperature gradient in the occupied zone

Smart selection tools for system calculation

ACON, our computer-aided selection program for air handling units, offers rapid selection to specific project requirements and provides you with all the information you will need. The program is web based and always up-to date without the need to download patches or program updates.

ExSelAir is Fläkt Woods’ unique web selection tool for air terminal devices, chilled beams, convectors, fan coils and silencers. In both these selection tools you will find product dimensions, technical data, LCC-calculations, technical catalogues, directions for installation, adjustment and maintenance.

ControlsFläkt Woods offers a wide range of integrated control solutions for air hand-ling and indoor climate systems. Factory mounted an pre-wired controls will reduce installation time and simplify on-site logistics. Preprogrammed and factory tested control applications based on Fläkt Woods extensive expe-rience also means a fast commissioning process and will secure a reliable and energy efficient operation of the system. Based on support for open standard communication protocols, integration to a building management system can easily be carried out by an independent system integrator.

With our broad range of products and century-old experience, one thing is obvious to us; You have to look at the big picture. It is by carefully combining products into systems, utilizing smart controls, one can achieve the best energy solutions.

When the pieces fit, you get the big picture

Air handling unitsOur comprehensive Air Handling Unit offering allows us to deliver optimised solutions for any customer. Our R&D work focuses on reducing energy consumption and creating factory complete air handling system solutions with controls. Our experience in the marine, off-shore, pharma-ceutical and hospital markets makes us the perfect partner for such applications.

Twin WheelsRotary heat exchangers are used for energy efficient heating and cooling recovery in air handling units. The Twin Wheel controller operates rotors and cooling coils in sequence to a dew set-point value, thereby limiting the supply air humidity level whilst maintaining a precisely matched indoor air quality.

e3 – Fläkt Woods

Integrated advantages

Following the Kyoto protocol the European Union has set a target to reduce energy consumption. For buildings the target is set at a 22% reduction by 2010. It’s called the EPBD directive.

To address the requirements of the EPBD direc-tive, Fläkt Woods has poured a lot of effort into creating the e3 Concept. Our solution is a broad approach leaving no stone unturned to achieve optimum results.

High-performing components provide a good start, but it is by combining products into an integrated system, utilizing smart control, that one can achieve the best energy solutions.

The e3 logo is used to highlight products and systems that deliver savings on both Energy, Economy and the Environment.

Chilled beamsIn systems with Chilled Beams, the indoor air is cooled by means of cold water. Chilled beams create a stable and comfortable environment by supplying draught free cooling. By using Chilled Beams up to 75% of the total cooling capacity will be handled by the water. Apart from the energy saving it also means less ductwork for air, smaller air handling units and lower noise.

ChillersThe Fläkt Woods range of chillers are designed to minimise the overall annual energy consumption in all types of buildings. Fläkt Woods’ heat and cooling recovery systems (e.g. Econet) allow for the deployment of smaller chillers than would otherwise be the case. This leads to significantly reducedinvestments and operational cost.

When outdoor air is warmer than the exhaust airflow there is a need for cooling. The hygroscopic rotor then reduces temperature of the incoming air. Simultaneously it transfers moisture from the in-bound to the outbound air flows (in cases where absolute humi-dity is higher outdoors)

After passing through the hygro-scopic rotor the air passes through the cooling coil, where the temp-erature is reduced further and moisture is condensated down to required levels. Since the air has already been cooled by the hygroscopic rotor, the demand for cooling is lowered. The saving can be up to 50% of the nominal required cooling effect, while at the same time the need for a following re-heating battery in most cases disappears.

The now dehumidified and coo-led air continues to the sensible rotor, where heat from exhaust air is recovered and used to re-heat it. The air is supplied to the building, with controlled levels of both temperature and humidity.Note that the temperature exchange in the sensible rotor, where exhaust air is cooled, further improves the cooling recovery of exhaust air in the hygroscopic rotor!

Twin Wheel advantages in overviewThe Twin Wheel system contains three main parts; the hygroscopic rotor, a cooling coil and a sensible rotor.

1 2 3

Exhaust air

Outdoor air

Extract air

Supply air

Hygroscopic rotor

Sensible rotor

Cooling coil

Count on savings

Air flow rate 5 m3/s • Outdoor condition: 29°C dry bulb, 50% relative humidity

Required supply air condition: 20°C with 8 g/kg absolute humidity

Exhaust air design condition: 23°C with 9 g/kg absolute humidity

The total cooling demand is 184.4 kW and the reheat demand is 56.5 kW.

With the twin wheel system the first rotary heat exchanger (green) recovers

100 kW of cooling leaving just 84.4 kW for the cooling coil. The reheat demand

is furnished by the second rotary heat exchanger (red) and the supply fan.

Laboratory testedThe Twin Wheel system has been tested in our laboratory

under defined and accurately measured conditions.

Now let’s see what the Twin Wheel system can achieve in real life! The situation is a typical setup where there are specific demands on both temperature and humidity to maintain a good indoor climate.

27.311.3

16.19.5

23.09.5

29.012.5

18.010.5

12.08.0

18.98.0

20.08.0

Dry bulbhumidity

5.0 m3/s

5.0 m3/sC / g/kg

Extract

Supply

Kaunas AKROPOLIS will be the biggest shopping centre in Kaunas and in central Lithuania, with a wide selection of national and international stores.

The AKROPOLIS shopping centre in central Lithuania will attract customers from all over Lithuania and neighbouring countries. The Akropolis shopping centre in Kaunas, Lithuania includes an ice rink. To avoid fog in the area around the rink it is necessary to supply air at a temperature of 16°C and an absolute humidity of 8 g/kg. The outdoor design condition is 27°C and 55% relative humidity (12.3 g/kg).

Two EU air handling units each equipped with two rotary heat exchangers supply a total of 15.4 m3/s. The total cooling demand is 448 kW and the reheat demand is 53 kW. By means of the twin rotor system the cooling demand on the chiller is reduced by one third to 300kW and the reheat demand is eliminated. Not only is the running cost reduced but also the size of the chiller plant.

Reference projects

FACTS AbOuT KAuNAS AKROpOLIS

• 73,063 m2 total area

• Supermarket ”hyper-Maxima” - 6,778 m2

• More than 220 operators

• More than 2,500 fast food and

restaurant seats

• Over 2,759 parking spaces

• 9 million visitors a year are expected

• Multiplex cinema – 7 screens, more than

1,418 seats

Akropolis shopping center Kaunas, Lithuania

”By means of the twin rotor system the cooling demand on the chiller is reduced by one third to 300kW and the reheat demand is eliminated.

Greenwich peninsula London, England

As part of what is believed to be one of the largest chilledbeam contracts in the London area, Fläkt Woods has supplied the complete £1.25 million ventilation solution for the Peninsula Central office development, part of the Terry Farrell’s Greenwich Peninsula master plan in London. In addition to Fläkt Woods supplying over 2,300 active chilled beams, they are also provi-ding air-handling units, VAV boxes and displacement terminals.

At 196,000sq ft the first of two developments 14 Pier Walk was opened in June 2009 and will form one of 3 new head office hubs for Transport for London. TFL have taken a 20 year lease on the building with the first of 1800 staff already at work at the-state-of-the-art green office. The second building Mitre Passage comprising 115,000 sq ft will be ready for occupation at the end of 2009.

The new twin wheel technology is expected to reduce energy costs on summer cooling. Mike Beeton, Chilled Beams Product Manager explains, “Using our knowledge of twin wheel techno-logy and active chilled beam systems, Fläkt Woods engineers have created a more efficient method of providing dehumidification to the primary fresh air.”

FACTS AbOuT GREENWICh pENINSuLA

• Peninsula Central is a 3.5 million sq ft

business district at the heart of the

Greenwich Peninsula redevelopment

• One of the largest chilled beam contracts

in the London area

• The building (14 Pier Walk) has officially

been awarded a BREEAM “Excellent” rating

with a score of 71% and an Energy Perfor-

mance Certificate band B with a score of 37

Further referencesUnilever, Kingston, UK

Manchester Metropolitan University,

UK Fitzrovia, London, UK

M W Kellog, London, UK

227 Tottenham Court Road, London, UK

Bidborough House, London, UK

John Dalton Building, Manchester, UK

We Bring Air to Life

Fläkt Woods Group SA18, avenue Louis Casaï, CH-1209 Geneva, SwitzerlandTel. +41 22 309 3800email info@flaktwoods.com www.flaktwoods.com

See global website for international sales offices www.flaktwoods.com

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Fläkt Woods is a globalleader in air management.We specialise in the design and manufacture of a wide range of air climate and airmovement solutions. And our collective experience is unrivalled.

Our constant aim is toprovide systems thatprecisely deliver requiredfunction and performance, as well as maximise energy efficiency.

Air handling units (Ahus)

Modular, compact and small AHU units. Designed to ensure optimisa-tion of indoor air quality, operational performance and service life.

Air Terminal Devices and Ducts

Supply and exhaust diffusers andvalves for installation on walls, ceilingor floor are all included in our largerange and fit all types of applications.

Chilled beams

Active induction beams for ventilation, cooling and heating, and passive convection beams for cooling. For suspended or flush-mounted ceiling installation – and multi-service config-uration. With unique Comfort Control and Flow Pattern Control features.

Residential ventilation

A complete range of products forresidential ventilation. Consists ofventilation units, exhaust air fans andcooker hoods designed to optimiseindoor comfort and save energy.

Energy recoveryDessicant-based product and systems that recover energy, increase ventilation and control humidity.

Fans

Advanced axial, centrifugal andboxed fans for general and specialistapplications. Comprehensive rangeincluding high temperature and ATEXcompliant options. Engineered forenergy efficiency and minimised lifecycle cost.

Chillers

Air-cooled and water-cooled chillerswith cooling capacity up to 1800kW.Designed to minimise annual energyconsumption in all types of buildings.

Controls and drives

Variable speed drives and controlsystems, all tested to ensure totalcompatibility with our products.Specialist team can advise on energysaving and overall system integration.

Acoustical products

A complete line of sound attenuating products, including rectangular and round silencers, Media Free silencers, custom silencers and acoustic enclosure panels.

Solutions for all your air climate and air movement needsFläkt Woods is providing solutions for ventilation and air climate for buildings as well as fan solutions for Industry and Infrastructure.