REHAU AWADUKT THERMO GROUND-AIR HEAT EXCHANGER SYSTEM FOR CONTROLLED VENTILATION. Building Solutions Automotive Industry

Transcription

1 REHAU AWADUKT THERMO GROUND-AIR HEAT EXCHANGER SYSTEM FOR CONTROLLED VENTILATION Building Solutions Automotive Industry

2

3 AWADUKT THERMO CONTENTS How a ground-air heat exchanger works The unique antimicrobial silver inner surface Pipe properties Domestic applications Commercial applications System design Grand designs Domestic case studies Commercial case studies Product range Product range for domestic applications AWADUKT Thermo pipes AWADUKT Thermo fi ttings Product range for commercial buildings AWADUKT Thermo pipes AWADUKT Thermo small header pipes AWADUKT Thermo fi ttings Accessories AWADUKT Thermo air inlet towers AWADUKT Thermo condensation discharge Frequently asked questions

4

5 AWADUKT THERMO ENERGY EFFICIENT SOLUTION FOR CONTROLLED VENTILATION Our fossil fuels are in short supply. This is why architects, specifi ers and contractors have been thinking laterally for the past few years. Energy-saving construction concepts are becoming ever more important. The ground-air heat exchanger AWADUKT Thermo from REHAU makes an important contribution to this. The ground s ability to store energy is used to achieve on energy-effi cient controlled ventilation solution. REHAU has developed the fi rst ground-air heat exchanger with an antimicrobial inner layer. So, as well as saving both costs and energy, property developers can also make a considerable improvement to the quality of the air inside their buildings. The ground-air heat exchanger system AWADUKT Thermo antimicrobial was awarded innovation prizes in France, Poland in 2007 and UK in

6 AWADUKT THERMO HOW A GROUND-AIR HEAT EXCHANGER WORKS Temperature at air inlet + 30 C Temperature + 12 C of ground Summer Operation g Temperature at air inlet - 5 C + 16 C Exit temperature at end of G.A.H.E Exit temperature at end of G.A.H.E Ever improving insulation and the air tight construction of buildings means that controlled ventilation is becoming ever more important. The ground-air heat exchanger makes a considerable contribution to this, especially when used in conjunction with a heat recovery unit. As well as increasing the quality of life within the building, this also provides signifi cant energy savings by using the embodied ground energy to pre-condition the incoming ventilation air. So, on the one hand, heating costs can be saved, whilst on the other, the air conditioning system investment costs can also fall, especially in larger buildings. The ground-air heat exchanger takes advantage of the fact that the temperature of the ground, 1.5 to 2m deep, remains a relative constant temperature between 7ºC-12 C throughout the year. The incoming outside air passes through an underground pipe system to pre-heat it in winter and to pre-cool it in summer. Experience shows that a ground-air heat exchanger makes it possible to raise the temperature of air taken in by up to 9 K in winter, and to reduce it by up to 14 K in summer. + 4 C Temperature of ground + 10 C Winter Operation 6

7 AWADUKT THERMO THE UNIQUE ANTIMICROBIAL SILVER INNER SURFACE Bacterium Moisture Film Ion release Colony-Aormins individuals / test sample Environment Surface Base Polymer Silver particles PP (Standard) 0 hours PP (Standard) 24 hours PP Antimicrobial 0 hours PP Antimicrobial 24 hours Active effect of the antimicrobial inner pipe layer Results of the Fresenius Institute: comparison of PP (polypropylene) Standard v. PP Antimicrobial AWADUKT Thermo pipes from REHAU feature an antimicrobial inner surface. A special manufacturing process is used to incorporate physiologically non-toxic silver particles into the inner layer of the pipe. Silver particles are used against microbes in the medical sector and in household appliances such as fridges. The antimicrobial effect of silver was recognised as long ago as 4000 B.C., silver vessels were used to treat drinking water in ancient Egypt. In the 11th century, chalices were made from silver for hygiene reasons. This property of silver is used in a multitude of ways to the present day. This patented ground-air heat exchanger, with its antimicrobial inner pipe surface, considerably inhibits microbial growth. The antimicrobial property of the inner pipe surface has been tested and verifi ed by Institut Fresenius at Taunusstein, to ASTM Standard E2180 (see diagram above). 7

8 AWADUKT THERMO PIPE PROPERTIES Thermal Conductivity Heat conductivity W/(m* K) AWADUKT Thermo pipe system Inlet unit The air is passed into the ground-air heat exchanger through an air inlet tower. The air is fi ltered by either a coarse or fi ne fi lter to BS EN 779, eliminating dust and pollen. AWADUKT Thermo pipe system AWADUKT Thermo pipes have been specially developed to meet the requirements of ground-air heat exchanger systems. Highly effi cient, hygienic, reliable in terms of leakproofness and condensation discharge the pipe range features many of the attributes required of a ground-air heat exchanger by VDI 4640, the German guidelines on groundsource energy. AWADUKT Thermo pipes are also low maintenance. Once installed, the pipes can be high-pressure cleaned and inspected by camera. Solid walled polypropylene (PP) pipe This optimised PP pipe with enhanced heat conductivity provides excellent heat transfer between the ground and the air, thereby ensuring a high degree of thermal effi ciency. Antimicrobial inner layer AWADUKT Thermo pipes feature an inner layer unique amongst ground-air heat exchanger pipes. This is achieved by a special process that incorporates silver particles into the inner layer of the base polymer. The result is that the fresh air inside the system is hygienic, containing virtually no germs. High longitudinal rigidity The high longitudinal rigidity of AWADUKT Thermo pipes prevents sagging, so that condensation is safely discharged instead of forming puddles at the lowest points. Pipes with inadequate longitudinal rigidity are not to be recommended for ground-air heat exchangers. Radon-Proof Radon is a natural, colourless, odourless radioactive inert gas encountered in rocks and in the ground. It is produced by the natural breakdown of the elements uranium and thorium. Radon diffuses through the ground, dissolves in water and escapes to the atmosphere at the ground surface. 8

9 AWADUKT Thermo Pipe Soak away Condensation collection shaft Submersible pump with discharge 1 The components of AWADUKT Thermo make it a tried and tested radon-proof ground-air heat exchanger pipe system. The required degree of imperviousness is achieved, by the design of the special safety sleeve featuring fi xed seals that cannot be pushed out. Wide range of fittings A broad range of mouldings means that the REHAU ground-air heat exchanger system can be laid out just as you want it. Bends, branches and connection sleeves are available for each pipe diameter. This makes a ring of pipes around the building just as achievable as a Tichelmann grid arrangement. Condensation discharge Condensation can occur in the pipe system, particularly in summer, when the air in the pipes is cooled. To make sure this does not affect the function of the ground-air heat exchanger in the long term, and to avoid odours, this condensation has to be effectively discharged. Condensation discharge for buildings without cellars In buildings without cellars, condensation has to be pumped out through a condensation collection shaft. 2 This shaft stands on a flat base. To prevent any unfi ltered air getting into the system through this shaft, it is fi tted with an airtight cast lid. The condensation is discharged from the ground-air heat exchanger pipe system to the condensation collection shaft via a branch. A standard submersible pump with internal fl oat is used to pump out the condensation. Condensation discharge for buildings with cellars In buildings with cellars the condensation can be discharged through the drain. This is achieved via a condensation branch located at the lowest point in the ground-air heat exchanger pipe system. To prevent any unpleasant odours, a ball siphon is incorporated between condensation discharge and drain. Wall penetration A wall inlet must be incorporated into the exterior wall for the pipes to enter the building correctly. REHAU provides the right solution for each different pipe diameter. In situations where the installation is below the water table, special types of wall inlets are required. 1 Safety-lock sealing system 2 Condensation discharge (for buildings without cellars) 9

10 AWADUKT THERMO DOMESTIC APPLICATIONS

11 1 Air inlet tower With a range of fi lters (G4 or F6) for hygienic, dust and pollen free air supply 6 2 AWADUKT Thermo Pipe System - Solid walled PP pipe for optimised heat conductivity - Antimicrobial inner layer to prevent microbial growth - High longitudinal rigidity for reliable condensation discharge - Radon-proof by virtue of special sealing system - Wide range of fi ttings for layout fl exibility 3 Condensation discharge This is installed towards the end of the system to remove any condensation formed during the heat transfer Heat recovery unit Distribution of fresh fi ltered air Extraction of warm, stale air Wall inlets 11

12 AWADUKT THERMO COMMERCIAL APPLICATIONS DN 1200 air inlet towers AWADUKT Thermo is also well suited to commercial applications, in particular in the health and education sectors. These buildings require a constant source of fresh, filtered air due to the high occupancy levels. Otherwise carbon dioxide build up can be a problem. The cooling effects of the ground-air heat exchangers are of particular benefi t to large buildings in summer. It is possible to achieve signifi cant air conditioning energy savings and, in some cases, even remove the need for air-conditioning completely. A ground-air heat exchanger can in some cases supply 10% of a commercial building s energy demand from on-site renewable sources. Pre-heating the ventilation air also provides signifi cant cost savings on the heat recovery unit. A large open area is normally required for commercial applications (e.g. a sports pitch is ideal). However, sometimes it may be benefi cial to put the pipes under the foundations. It must be noted that this method does not allow for solar gain, which favourably increases the temperature of the ground, but still provides an effective solution and saves installation costs. Joseph Rowntree School 12

13 AWADUKT THERMO COMMERCIAL APPLICATIONS: EDUCATION SECTOR AWADUKT Thermo has been extensively specifi ed in the education sector, in particular, due to the increasing cooling requirements of new-build schools and colleges. Building fabrics are becoming increasingly air-tight and insulation levels are constantly increasing, therefore overheating is becoming more of an issue. Here are some examples of installed education projects. Queen Elisabeth School, Wimborne QE School is a Building Schools for the Future Pathfi nder project and is one the largest AWADUKT Thermo installations carried out in the UK. 3 seperate Tichelmann grids were installed under 3 blocks of the building to pre-heat and precool the air before it entered the mechanical ventilation system. Each grid supplies a fl ow rate of ca. 12,000m3/h and comprises of 30 runs of DN250 pipe, each around 60m long, with a header pipe of DN1050. Bypasses were included for each grid to increase the total energy savings of the system. Installing the pipes under the building allowed signifi cant cost savings for the excavation. Pears National Centre for Autism, North London AWADUKT Thermo, with its antimicrobial properties, was specifi ed due to the importance of a comfortable learning environment for children with special educational needs. The total air fl ow of 7,800m3/h was split down into 3 small grids, each with a DN500 header pipe and 8 runs of DN200 heat transfer pipe. The total length of heat transfer pipe was 432m. The pipes were laid under a playing fi eld and special air intakes were designed for the project, which consisted of the air being drawn through custom benches and then passing underground through the system. This project also included a bypass for each grid to increase energy savings. Nairn Academy, Scotland This project was a specialist unit for children with severe and complex needs and optimum comfort for the pupils was vital for the client. The minimal energy required to run the system and the comfort cooling were the main drivers for the project. 3 runs of DN200 pipe, each 30m long, was laid in a Tichelmann layout with a DN250 header pipe. The system was installed underneath the building to save installation costs but also increase the outputs for cooling. Queen Elisabeth School Pears National Centre for Autism Nairn Academy 13

14 AWADUKT THERMO SYSTEM DESIGN Design There are various factors which need to be taken in to account when designing a ground-air heat exchanger system: - Volume of building + air change rate (l/h) - Air fl ow rate (m 3 /h) - Pipe material - Depth at which pipes are laid - Pipe arrangement (grid/ring) - Soil type - Site climate - Ground water levels When determining the pipe diameter, a max. fl ow speed of around 3m/s must not be exceeded in the heat transfer pipes, and 6m/s in the distribution/manifold pipes. This would negatively affect performance. REHAU s bespoke design software can be used to work out the optimum pipe sizes and lengths for a ground-air heat exchanger system for a specifi c project. It can also calculate the estimated energy savings in kwh/a for heating and cooling. If you are interested in obtaining a copy of the software please enquiries@rehau.com or visit REHAU can also provide a RIBA and CIBSE approved seminar on this technology entitled: Ground-air heat exchanger: Renewable source of controlled ventilation. If you would like to book a CPD seminar, please contact your local REHAU Sales Offi ces (details on back page). 14

15 Domestic For a typical domestic application, a minimum of 40m of pipework is required. This is either with a loop around the building or by a meander pattern. The optimum pipe diameter for air fl ow rates of up to 300m 3 /h is 200mm. For air fl ow rates up to 450m 3 /h, DN250 pipe is used. Commercial On commercial applications, it is usual to use a Tichelmann layout. This is a self-balancing system: whichever path the air fl ows, it travels the same distance, reducing the pressure losses. AWADUKT Thermo must be installed according to the latest installation guidelines. Please request a copy from REHAU prior to installation. Domestic Loop Layout House Tichelmann Pipe Layout Usually DN pipe is used for the heat transfer and DN 500, 800, 1000 or 1200 is used for the distribution pipe. The required air fl ow dictates the optimum pipe diameters. Air Intake Unit Pipe House 2 main pipe layouts 15

16 AWADUKT THERMO GRAND DESIGNS AWARDS 2009 At its launch in 2008, REHAU knew that its AWADUKT Thermo ground-air heat exchanger system was a unique and highly effi cient product in the renewable energy market. It has now received an independent endorsement for that claim with the product being shortlisted for a prestigious 2009 Grand Design Award in the Innovative Building Products category. AWADUKT Thermo was fi rst shown on Grand Designs TV programme on 2nd April 2008 at the Bluebell Bungalow in Kent. For the project, 40m of DN315 pipe and 30m of DN250 pipe was used to supply the 2 mechanical ventilation heat recovery (MVHR) units on the property with an air fl ow rate of 300m3/h. Since the airing of the programme, the awareness of the product has increased dramatically and the performance is also being measured by the client. Although AWADUKT Thermo didn t ultimately win the award when the results were announced in May 2009, REHAU believes that just to be shortlisted by the infl uential team of judges was a very signifi cant achievement. The innovative AWADUKT Thermo system has also won innovation awards in France and Poland. Grand Designs House, Kent - Episode aired on 2nd April, m DN 315 pipe splits into 2-30m DN m3/h air fl ow rate - Uses 2 heat recovery units - Also used RAUGEO energy piles and REHAU underfl oor heating 16

17

18 AWADUKT THERMO DOMESTIC CASE STUDIES BASF House, University of Nottingham - Showcasing affordable and sustainable technologies - 34m of DN 200 AWADUKT Thermo pipe - 1 air inlet, 2 air outlets - Uses solar atrium to increase performance in winter and reduce solar gain in summer - Performance being datalogged by the university Residential Project, Berkshire Downs - Used in conjunction with heat recovery unit - 80m of DN 200 AWADUKT Thermo pipe - 5 bed new build Lakes by Yoo luxury houses being built over the next 3 years - Each house air fl ow rate 900m 3 /h - 4 runs of DN DN 315 header pipe 18

19 AWADUKT THERMO COMMERCIAL CASE STUDIES Tesco Supermarket, Poland - Pipes laid under building foundations to save installation costs - 700m of DN 200 AWADUKT Thermo pipe, DN 500 distribution pipe - Air fl ow rate = 2,700m 3 /h - 1 year research project by University of Poznan - In summer 37 C to 19 C, in winter from -15 C to +7 C - Coeffi cient of performance is over 20 Ards Business Centre, N Ireland - Air fl ow rate 4,300m 3 /h - DN 800 distribution pipe - 448m of DN 315 AWADUKT Thermo pipe - Installed in diffi cult site conditions Sutton Life Centre, Surrey Grid 1 - Air fl ow rate 2,880m 3 /h - DN 500 header pipe - 1x18m runs of DN 200 Grid 2 - Air fl ow rate 7,200m 3 /h - DN 750 header pipe - 35x30m runs of DN

20 1 1.1 PRODUCT RANGE FOR DOMESTIC APPLICATIONS AWADUKT THERMO PIPES AND FITTINGS AWADUKT Thermo Pipe with push-fit and safety-seal, pipe-ends with dust covers Material: RAU-PP 2387/2400 antimicrobial Colour: RAL 5012 soft-blue, inside layer aluminium-grey External Diameter Length (BL) d 1 Dmax t Weight S 1 (kg/m) pcs./ HRV* *HRV = Timberframe Crate AWADUKT Bend with push-fit sleeve and safety-seal Material: RAU-PP 2300 Colour: RAL 5009 azure-blue External Diameter a z 1 z 2 Weight (kg/pc.) Unit/ Packging AWADUKT Single Branch 45 with push-fit sleeve and safety-seal Material: RAU-PP 2300 Colour: RAL 5009 azure-blue External Diameter z 1 z 2 z 3 Weight (kg/pc.) / Unit/ Packging 20

21 1 1.2 PRODUCT RANGE FOR DOMESTIC APPLICATIONS AWADUKT THERMO FITTINGS AWADUKT Double-Fit Sleeve Joint with push-fit and safety-seal Material: RAU-PP 2300 Colour: RAL 5009 azure-blue External L Dmax t Weight Unit/ Diameter (kg/pc.) Packaging AWADUKT PP Slip Coupler with push fit sleeve and safety seal Material: RAU-PP 2300 Colour: RAL 5009 azure-blue DN/OD L Dmax ,00 Weight (kg/pc.) AWADUKT Thermo End Cap* with EPDM sealing ring and welded-in PP end plate L Material: RAU-PP 2387/2400 Colour: RAL 5009 azure-blue DN Weight Unit/ External Diameter L (kg/pc.) Packaging

22 2 2.1 PRODUCT RANGE FOR COMMERCIAL BUILDINGS AWADUKT THERMO PIPES AWADUKT Thermo Pipe with push-fit sleeve and safety-seal, pipe-ends with dust covers Material: RAU-PP 2387/2400 antimicrobial Colour: orange-brown External Diameter Length Dmax Weight (BL d 1 t S 1 (kg/pc) * pcs./ HRV *Delivery time on request GAHE Header Pipe DN630 with push-fit sleeve and safety-seal, pipe-ends with dust covers Material: RAU-PP 2300 Colour: orange-brown DN/OD BL d 1 D max Weight t S 1 (kg/pc) * *Delivery time on request 22

23 2 2.2 PRODUCT RANGE FOR COMMERCIAL BUILDINGS AWADUKT THERMO SMALL HEADER PIPES AWADUKT Thermo Header* pipe-ends with dust covers, header with spigot ends on both sides DN BL Material: RAU-PP 2387/2400 antimicrobial Colour: RAL 5012 soft-blue, inside layer aluminium grey (with connecting branch DN 200), otherwise orange-brown dn L1 L2 Distribution Pipe DN Connecting Branch DN No. of sockets Socket spacing L Length (BL) * * * * * * * * * * * *Delivery time on request 23

24 GAHE Header DN630* pipe-ends with dust covers, header with spigot ends on both sides DN BL Material: RAU-PP 2300 Colour: RAL 5012 soft-blue, inside layer aluminium grey (with connecting branch DN 200), otherwise orange-brown dn L1 L2 Distribution Pipe DN Connecting Branch DN No. of sockets Weight (kg/pc) Socket spacing L1 Socket spacing L * * * * * * * * * * * * BL *Delivery time on request AWADUKT Thermo Distribution Pipe Special Transition Piece DN500* sleeve can be pushed on supplied with 1 loose sealing ring OD = DN L External Diameter L *Delivery time on request 24

25 2 2.3 PRODUCT RANGE FOR COMMERCIAL BUILDINGS AWADUKT THERMO FITTINGS AWADUKT Elbow with EPDM sealing ring Material: RAU-PP 2300 Colour: orange-brown External Diameter a Z 1 Z 2 Weight (kg/pc.) * * * * * * * * AWADUKT PP Slip Coupler with EPDM sealing rings Material: RAU-PP 2300 Colour: orange-brown DN/OD L D max Weight (kg/pc) * * Delivery time on request *

26 AWADUKT Single Branch 45 with push-fit sleeve and safety-seal Material: RAU-PP 2300 Colour: orange-brown External Diameter Z 1 Z 2 Z 3 Weight (kg/pc.) / * 250/ / * 315/ * 315/ / * 400/ * 400/ * 400/ * 500/ * 500/ * 500/ * 500/ * 500/ * 630/ * 630/ * 630/ * 630/ * 630/ * 630/ *Delivery time on request AWADUKT Double- Fit Sleeve Joint with EPDM sealing rings Material: RAU-PP 2300 Colour: orange-brown External Diameter L D max t * * Weight (kg/pc.) *Delivery time on request 26

27 AWADUKT Connecting Reducer with EPDM sealing rings Z 1 Material: RAU-PP 2300 Colour: orange-brown d1 d2 External Diameter (d 1 /d 2 ) Z / / / * 500/ * 630/ Weight (kg/unit) *Delivery time on request DN dn L External Diameter (DN/dn) L * 315/ * 400/ * 500/ *Delivery time on request AWADUKT End Cap* with EPDM sealing ring and welded-in PP end plate L Material: RAU-PP 2300 Colour: orange-brown DN External Diameter L * *Delivery time on request 27

28 3 3.1 ACCESSORIES AWADUKT THERMO AIR INLET TOWERS AWADUKT Thermo Air Inlet Tower with ribbed cover, pipe element with footflange, suitable for AWADUKT Thermo pipe push-fit socket, without filter inlay Material: High-grade steel, ground Diameter Height Weight (kg/unit) *Delivery time on request AWADUKT Thermo Filter filter class G4 or F6/G2 to EN 779 suitable for AWADUKT Thermo Air Tower Diameter Diameter Filter Class G F6 /G * 250 G * 250 F6/G * 315 G * 315 F6/G * 400 G * 400 F6/G * 500 G * 500 F6/G * 630 G * 630 F6/G2 *Delivery time on request 28

29 3 3.2 ACCESSORIES AWADUKT THERMO CONDENSATION DISCHARGE AWADUKT Thermo Condensation Discharge R* e.g. for residential buildings and other buildings with cellars, with welded-on half push-fit and safety-seal, inspection opening, branch 90º, dimensionally identical with spigot end on both sides as well as welded on discharge DN40 Material: RAU-PP 2300 antimicrobial Colour: RAL 5012 soft-blue, grey (DN200), otherwise orange-brown Illustration differs from actual size External Diameter AWADUKT Thermo Condensation Discharge S* e.g. for residential buildings and other buildings with basements, with sleeve joint and sealing ring as standard design Material: RAU-PP 2300 Colour: RAL 5012 soft-blue, grey (DN200), otherwise orange-brown External Diameter I 1 I 2 t Unit/Packaging / X / X / X * 400/ X * 500/ X *Delivery time on request 29

30 Ball Siphon for Condensation Discharge with elbow connection DN 40 and ball check valve Material: RAU-PP Colour: white, yellow Unit/Packaging single AWADUKT Thermo Condensation Collection Shaft i.e. for buildings without a basement, with flat floor and 1 connection diameter DN 200 (pointed end): Material: RAU-PP Colour: RAL 5009 azure-blue External Unit/ Diameter Size I 1 I 2 I 3 Packaging loose AWADUKT Thermo Cast Iron Cover for Condensation Collection Shaft, Cast Iron Cover frame incl. seal and lid, weatherproof Material: cast iron Colour: RAL 9005 black External External Weight Diameter Type Diameter (kg/unit) Unit/Packaging D 400 SWR* 420x loose *Surface water resistant 30

31 3 ACCESSORIES AWADUKT Thermo Wall Inlet DN * (For Special Applications) for use where ground water pressure exists, pressure tightness max. 3.0 bar high-grade steel design, sealing element made of EPDM rubber, in pre-assembled link design Colour: blue External Diameter * * * * * *Delivery time on request AWADUKT Thermo Wall Casing Piece* for the bridging of pipes through walls, specifically for use where water pressure exists, pressure tightness max. 5.0 bar, made of asbestos-free fibre cement concrete Colour: light-grey External Diameter Connecting Pipe Diameter * * * * * *Delivery time on request 31

32 GAHE Sealing Collar For use in areas of high ground water. Pressure rated max. 4.0 bar. To be set in concrete. Material: EPDM Synthetic rubber Colour: black DN/OD Weight (kg/pc) * * *Delivery time on request AWADUKT Thermo Wall Inlet with lip seal for non-pressured ground water Material: RAU-SB 100 Colour: natural External Diameter Installed Length L D max approx * * Weight (kg/unit) *Delivery time on request Lubricant for sleeve joints Capacity Unit/Packaging g g g g

33 AWADUKT THERMO FREQUENTLY ASKED QUESTIONS Is it not healthier to open a window? A ventilation system supplies just the right amount of fresh air to a building in a controlled manner. The antimicrobial inner pipe surface and the air fi lter mean health concerns are unfounded. There are also other advantages, such as the avoidance of draughts, dehumidifi cation and reduction of noise from outside. These all boost the feel-good factor within one s own four walls. What running costs does a ground-air heat exchanger entail? Ground-air heat exchanger running costs are minimal. The small amount of power used by the fan and the costs of regularly checking or replacing the air fi lter are the only running costs. How often does the filter need cleaning? The fi lter should be cleaned or replaced every 6-12 months, depending on fi lter class and on local environmental conditions. What is a ball siphon? When outside air cools in the ground-air heat exchanger pipes during the summer months, condensation forms. If this needs to be discharged through the drains of the building, it is directed to a siphon so that odours are avoided. As, with standard siphons, odours are prevented by the water standing in the pipe, there is always the danger of the siphon drying out and bad air entering the ventilation system from the drains. The ball siphon, with its integrated ball valve, prevents undesirable odours from accessing the ground to air heat exchanger pipes from the drains. How long does the antimicrobial effect last? The antimicrobial effect lasts as long as the pipe. No layer of dirt can be expected to form on the inside of the pipe as the air is fi ltered at the inlet. Occasional rinsing of the pipes will make them continue to function for many years. How are AWADUKT Thermo pipes laid? AWADUKT Thermo pipes are laid in the same way as drains. The only difference is that there are no special regulations for fi lling the trench. It is best to fi ll with solid earth rather than with sand, as sand conducts heat less effi ciently than earth (e.g. clay). The pipes should fall 2% in direction of fl ow. The condensation discharge branch or collection shaft is therefore to be located at the lowest point. What are the important differences between a standard PVC drainpipe and AWADUKT Thermo ground-air heat exchanger pipes made of special PP? AWADUKT Thermo pipes have been specially designed for use in ground-air heat exchanger systems: - AWADUKT Thermo pipes are equipped with an antimicrobial inner surface layer to minimise the danger of germs. - AWADUKT Thermo pipes are highly conductive and provide better heat transfer between air and ground. PVC pipes are often sandwich foamed and thus have an unwanted insulating effect. - AWADUKT Thermo pipes are particularly suitable for laying in ground with large granular elements as they are innately robust and are not sensitive to impacts. How does the antimicrobial inner layer work? Particles of silver that are physiologically non-toxic are incorporated into the inner layer of the pipe by a special process. The antimicrobial properties of silver signifi cantly reduce microbial growth on the inside of the pipe. 33

34 FURTHER REHAU PROGRAMMES RAUGEO PE-Xa probe RAUGEO horizontal collectors RAUGEO PE-Xa Energy Pile RAUGEO Helix new generation RAUTHERMEX district heating pipe REHAU Underfloor Heating 34

35

36 UK & IRELAND SALES OFFICES London, REHAU Ltd, The Building Centre, 25 Store Street, London WC1E 7BT Phone: Fax: Slough, Units 5 J & K, Langley Business Centre, Station Road, Langley, Slough SL3 8DS Phone: Fax: Manchester, Brinell Drive, Irlam, Manchester M44 5BL Phone: Fax: Glasgow, Phoenix House, Phoenix Crescent, Strathclyde Business Park, Bellshill, North Lanarkshire ML4 3NJ Phone: Fax: Dublin, 9 St. Johns Court, Business Park, Swords Road, Santry, Dublin 9 Phone: (0) Fax: (0) Our verbal and written application engineering advice is based upon experience and the best of our knowledge. However it is to be regarded as non-binding information. Working conditions and use under conditions for which the product was not intended and over which we have no infl uence exclude any claim resulting from our information. We recommend that a suitable check is made as to whether the REHAU product is suitable for the envisaged purpose. Application, use and processing of the products is carried out beyond the scope of our control and are therefore carried out exclusively at your own responsibility. If liability should still apply, then this is restricted, in the case of all damage, to the value of the goods supplied by us and used by you. Our warranty applies to the consistent quality of our products as per our specifi cation and in accordance with our general terms and conditions of delivery and payment. This document is protected by copyright. All rights based on this are reserved. No part of this publication may be translated, reproduced or transmitted in any form or by any similar means, electronic or mechanical, photocopying, recording or otherwise, or stored in a data retrieval system EN/385/DAIR/06.10