VENTILATION PIPES AND DUCTS

Pure and Natural Air Breathe Through the Forest

CONTENT

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⊚ 03丨 About Us ⊚ 07丨 Introduction of Ventilation System and its Functional Features

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⊚ 09 丨 Introduction of Ventilation Pipes and Ducts in Ventilation System ⊚ 29l Pipe Connection Construction Steps and Precautions

⊚ 32丨 Product Patents and Test Reports

About Us

{>} Established in 1986, LESSO (Stock Code: 02128.HK) is a global leader in home furnishings and building materials. The Group′ s business porfolio spans plastic piping, building materials and home furnishings, environmental protection, new energy, supply-chain service platforms and others. It offers a wide range of products such as pipes, photovoltaics, plumbing and sanitary ware, integral kitchen materials, integral doors and windows, aluminum formwork and smart scaffolds, water purifiers, water-proofing materials and sealants, fire-fighting equipment, valves, cables, lighting, hygiene materials, items for environmental protection, agricultural facilities, and oceanic aquaculture cages. In 2023, LESSO′ s sales revenue reached over USD 4.38 billion.

⊚ Since implementing a strategy of globalization and expanding its global presence, LESSO has evolved into a sophisticated multinational. It boasts more than 30 advanced production bases worldwide, broadening its industrial and sales networks to cover Asia, North America, South America, Europe, Africa, and Oceania. This enables LESSO to provide quality products and services for global customers in accordance with its continuously improved strategic layout in a timely and efficient way.

{\scriptsize{>}} LESSO has founded its R&D center with more than 1,ooO scientific researchers, nationally accredited enterprise technology center, and two post-doctoral workstations to support its innovation and technical development. The Group has taken a leading role in the revision of over 120 international and Chinese industry standards. LESSO owns over 3000 patents (some of them are pending), and provides over 10,00o varieties of products, making it one of the most comprehensive manufacturers in the piping industry. Its products are utilized globally in different areas, including home decoration, civil construction, municipal water supply, drainage, energy management, power supply and telecommunications, gas supply, fire-fighting, environmental protection, agriculture, oceanic aquaculture, etc.

① True to its idea of “Envisioning the Better, Building the Future", LESSO remains commited to creating a better living environment, and advocating ideal cities featuring greenness, livability, and efficiency. With concerted efforts from various sectors, LESSO willfully play its role in sustaining healthy and beautiful space so that global residents could enjoy a comfortable life.

LESSO Research Institute & Testing Center

LESSO College

Training Apartment

Background of Product Market

The substance that people come into contact with the most daily is air, with an average daily inhalation of around 25kg, which is about 10 times the amount of food and drink consumed

People have always thought that the serious air pollution often occurs outdoors. In recent years, however, with the increasing improvement of building energy conservation, rooms have become increasingly enclosed, resulting in poorer ventilation. In fact, the impact of indoor environmental pollution on human health is far higher than that of outdoor environmental pollution.

It hasbeenfound that anincreasingnumberofdiseases arerelated toindoorair quality.Various diseasesareeasilycaused because of the long-termexposure to outdoor air contaminated withPM2.5(suchas dust, pollen,vehicle exhaust, industrial emissions, etc.), along with harmful gases pervasive in enclosed indoor spaces (such as formaldehyde, radon, and benzene), second-handsmoke，cookingfumes,，carbondioxide \left(\mathsf{C O}_{2}\right) andbacteria.Therequirementsofcontinuousventilationcouldnot beachieved only through traditional ventilation solutions，includingopening windows，usingventilationfans，and air conditioners,whichnecessitates the installationofventilationsystem.

Thedecorationandfurniture
willleavetheresidueof
formaldehyde, benzene, TVOC, etc.
In hot and humid weather,
it is easy to grow
dust mites, odors,
and mold

Second-hand smoke contains more than 40 carcinogenic substances

Outdoor PM2.5 particulate matters, dust, and haze

Introduction of Ventilation System and its Functional Features

Ventilation system is a respiratory system that can deliver outdoor fresh air through the pipes and draught fans, which has been fitered and puried, into the indoor environment, while simultaneously discharging indoor air to outdoors
to maintain system balance, and realize indoor air discharging and scientic air convection.
The system continuously provides adequate amounts of fresh and clean air to the residences for 24 hours a day, creating an indoor air environment that is healthy, comfortable andsafe.
The ventilation system is mainly composed of draught fans, pipes (including pipes, pipe fittings, air difuser accessories, etc.) and controllers.

⊚ Functional features of ventilation system

⊚ Scope of application

Breathing natural and clean air enables you feel worriless. H2O

PE Ventilation Pipes

Product Introduction

High density polyethylene (HDPE) is a white powder or granular product. HDPE is non-toxic and odorless, with a crystallinity of 80% to 90% and a softening point of 125°C 135°C .and can be used at temperatures up to 100°0 . It offers superior hardness, tensile strength, and creep resistance compared with the low-density polyethylene. HDPE also exhibits excellent wear resistance, electrical insulation, toughness, and cold resistance. With its strong chemical stability, it remains insoluble in any organic solvent at room temperatures, and is resistant to the corrosion of the acid, alkali and various salts. HDPE flms have low permeability to water vapor and air,aswellas lowwater absorption.

Physical and mechanical properties of PE ventilation

o Food-grade PE material

ADVANTANGE

Madefrom high-qualityfood-gradePE material,the product is resistant to deformation during use, and providesgreatersafetyandenvironmental friendliness.

Duct Selection

⊚ Installation of PE ventilation duct

Precautions:

1. Seal rings shall be used between the ducts and draft distributing boxes to connect them. When cuting the pipes, professional pipe cuting tools should be used as much as possible to avoid burrs from pipe cuting, which will affect the fit installtion and lead to air leakage.
2. The materials should be stored away from direct sunlight as much as possible.

Ventilation System PE Dedicated pipe Fittings

A healthy home allows you breathing in a forest. PVC ventilation pipe

Advantages of PVC ventilation pipe Transmission and Distribution System

⊚ Fluid simulation platform is introduced for optimizing the pipe design of the system

LESSO is the first to introduce a fluid simulation platform into the field of ventilation system. This platform assists in fluid simulation technology for modeling and analysis, and optimizes the duct design of the system, effectively addressing issues such as unbalanced air volume distribution, significant air pressure loss, and noise disturbances that are prevalent in traditional designs that rely heavily on experience.

·Original scheme:The use of conventional elbows and T-shaped teesresultedinhighnoiseatairsupplyoutlet.

:Optimized scheme:After implementing long-sweep elbows and dovetail tees，systemnoise was significantly reduced.

When the conventional tee is used, the pressure distribution among the branches is uneven, and the air volume at the air supply outlet is very low. To control the air volume, control valves need to be added at the ends of thebranches,whichresults inincreasedairflowresistance ofthe system.

After the adjustabletees are applied, the pressure distributionamong the branchesbecomesbalanced,andnoadditionalcontrolvalveisrequired to controltheairvolume，whichreducesairflowresistanceofthesystem.

⊚ Long sweep, large flow, and low airflow loss

1. By adopting the streamlined structure of the long-sweep elbows, airflow organization is optimized and the local resistance is reduced. The airfow loss is decreased by 23.0% compared with using two 45° elbows.
2. By adopting the flow-guided structure of lateral crosses, airlow distribution in the branches becomes more uniform, and the local resistance is smaller. The airlow loss isreducedby 29.1% comparedwithusingtwo 45° lateral tees.

Long Sweep

·As shown in the streamline diagram, the long-sweep elbow provides a more uniform airflow distribution and lower airflow resistance compared with the traditionalcombinationoftwo \Phi1\uparrow0^{\star}45° elbowsandthe \Phi1\uparrow0^{\star}90° elbow.

Oblique cross

·Compared with the traditional connect fitting of two \Phi1\uparrow0^*45° lateral tees, the \Phi1\uparrow0^*45° lateral cross demonstrates a more uniform streamline of the light blue forward-flowing fluid at the branch outlet, which indicates a more even air volume distribution and better airflow organization.

The dovetail structure design is adopted to realize the smooth transition, ensuring smoother airfow distribution. <br>· As shown in the streamline diagram, the dovetail tee provides a more uniform airflow distribution and lower airflow resistance compared with the traditional equal tee,leading tobetter airfloworganization.

Full series of ventilation ducts with reasonable pipe diameter gradient

The 75-90-110-125-160-200-250 series of ventiltion pipes offers complete product specifications with reasonable pipe diameter gradient. The complete product specifications allw users to select the appropriate duct diameter according to the air volume of the system, which can greatly reduce the fresh air speed, as well as the resistance and noise of thesystem.

:Taking a fluid simulation analysis with a fresh air volume of 200m^{3}/\mathsf{h} as an example, when conventional DN110 ventilation pipe is replaced by DN125 ventilation pipe, the air speed is reduced from 6.3m/s to 4.9\mathsf{m}/\mathsf{s} and theresistance isreduced by 48.2%

Composition of PVC Dedicated pipe for Ventilation System Transmission and Distribution

Diversified Transmission and Distribution Modes, Optimized Product Installation, and Significant Functions

The transmission anddistributionmodes canbe flexibly selected according to different needs: both air supply and return from the above, or air supply from thebelow and airreturn from the above.

⊚ Transmission and distribution mode: Both air supply and return from the above

Ceiling-mounted quick pipe clamp

·The clamp design allows for quick clamping of the ducts with a simple press by hand. This design addresses the issue with traditional PvC pipe clamps thatrequireconstructionworkers tohold thepipe and secure it with at least two screws, significantly reducing thedifficultyoftheinstallationand increasing the efficiencyby 50%

Beam-through U-shaped tee

·The adoption of U-shaped structure caneffectively avoid thedamageto building reinforcement when drilling holes for the pipes pass through beams, ensuring the air supply at 100% air volume.The air supply volumeissuperiortothatofother beamcrossing devices on the market.

·The adjustable tee can be used to flexibly adjusttheairvolumeratiobetweenthe branch and the main pipe.The maximum adjustableratioof theairvolumebetweenthe branch and the main pipe can reach 6:1, resulting ina morebalancedairvolumewithin thesystem.Thestreamlinedcurvedvalve plate structure isconducive to guiding air flowtoreduceresistance andlower noise.

The design specification of flat ducts is 135\*32, and this product offers an 11% increase in air volume compared to the products with the specification of 130\*30availableonthemarket.

Since the underfloor air supply duct is laid under the floor, the needs for drilling through beams or working at heights are avoided, making the installation convenient. Made from PvC material, it offers excellent pressure and impact resistance.Additionally,the incorporation of reinforcing ribs in the middle enhances the product' s bearing strength by \boxed{5}{=} compared with similar productsonthemarket.

⊚ Transmission and distribution mode:

Air supply from the below and air return from the abr

The 45° variable and perfect combination addresses various installation problems

Whenmakingturns,two 45° flatelbowsareusedto realizesmoothturning andreduce airflowresistance. Theductscanbelaidaccordingtolocalconditions, and areeasytoinstall.

45° wall-climbing elbow

When climbing slopes or crossing sections, two or four 45° wall-climbingelbows areusedfortheinstallationoftheproduct.Comparedwiththetraditional 90° elbow,theadoptionoftheseelbowsnotonlyenableswallclimbing,butalso reducesairflowresistanceandmakestheinstallationmoreconvenient.

Products

ling-mounted duct: PVC-U round air pipe (round pipe)

25/26

·Products marked with an asterisk (\*) indicate that their molds are currently being improved.

⊚ Air diffuser series

Executive standard: Dedicated Air Diffuser for Ventilation System (QL/S 93-2019)

rfloor air supply duct: PVC-U oblate air duct (flat duct)

Executive standard: Rigid Polyvinyl Chloride (PVC-U) Ventilation Pipe and Pipe Fitings for Ventilation System (Q/LS 76-2022)

Construction Steps and Precautions of Pipe Connection

⊚ Construction steps of round pipe installed in suspended ceiling

1. Preparing tools

Before construction,prepare tools such as an angle grinder/a cutting machine,hammer drill, level, rubber hammer, measuring tape， and marking pen.

2. Measuring pipe length

Measure therequired lengthof thepipe at the suspended-ceilinglocationwithameasuringtapeon site to ensure the accurate cutting of pipe sections.

3. Cutting pipe

Use an angle grinder or cutting machine to cut the pipe,and polish the burrs and rough edges of the cutting surface to ensure that the cuttings aresmoothandperpendicularto thepipeaxis.

4. Marking the socket depth on the pipe

After cutting the dpipe sections, use a measuring tape and a suitable markingpentomark socket depth at the endsof thepipes

5. Installing pipe clamps

After positioning with a level, drill a hole by using a hammer drill to install the pipe clamps.

6. Pre-fixing the pipe installed in suspended ceiling

Place the cut pipe sections into the pipe clamps for pre-support and fixation.

7. Connection between the pipe and pipe fittings

Clean the pipe ends and the socket surfaces of the pipe fitings with a cloth, and then place the pipe into the sockets of the pipe fittings until they can no longer be pushed. Note: When inserting the pipe ducts into the pipe fittings, apply glue on the socket position to connect the pipe and the pipe fittings. If the glue-free connection is adopted, a small amount of soapywatercanbe appliedfor lubrication.

8. Fixing the connection between pipe and pipe fittings

Tap the ends of thepipe with a rubber hammer to connect thepipe andpipe fitting to the marking lines, and then tighten the pipe clamp. Note: If the installed position is subject to high stress or is at a turn, based on the actual situation,aluminum foil tape can be wrapped tightly around the connectionbetween the duct fittings and ducts for 1 to 2 turns, or self-tapping screws can be used for fixation.,

istruction steps of oblate ducts installed in suspended

Construction precautions

1. The direction and diameter of the ducts, and the installtion position of air difusers should meet the requirements of the ventilation system design drawings.
2. The sections of the ducts that cross through the walls and connect to the outdoor air diffusers must be flled with foaming agent for sealing, and the waterproof treatment shouldbeapplied.
3. Pipes and ventiltion equipment shall be connected through aluminum foil composite hoses.
4. PEE tapes can be used for the intermediate transition between the outdoor fresh air supply inlets and exhaust outlets, and the pipes in walls, and the silicon sealant should be used between outdoor fresh air supply inlets and exhaust outlets, and the outer walls.
5. When aluminum foil composite hoses are used between air ducts and difusers, the hose length should not exceed 30\ \mathsf{cm}

Construction Cases

LESSO

CHINA LESSO GROUP HOLDINGSLIMITED

(STOCK CODE: 2128.HK)

GUANGDONGLIANSU TECHNOLOGYINDUSTRIALCO.,LTD.

ProductionBase: LIANSU Industrial Estate, Longjiang Town, Shunde District, Foshan City, Guangdong Province 528318, China