Code of Practice for the Construction of Refuse Chutes in Multi storeyed Buildings

IS 6924 Scope Summary

• Scope: Covers design, construction, and location of chute systems including:

  • Chute
  • Inlet Hopper
  • Collection Chamber

• Purpose: Provides requirements for functional components of material handling chutes.

• Rounding Off: Final values from tests or calculations must be rounded as per IS 2:1960 (Rules for rounding off numerical values).

Key Points:

Rounding Off Rule (IS 2:1960)

• Round off final values to same decimal places as specified values.
• Ensures uniformity in test and design reporting.

If you need formulas or detailed design parameters, please specify the component or design aspect.

IS 6924 - Definitions (Clause 2.0 & 2.1)

• Scope: Covers design, construction, and location of three key components in a chute system:

  • Chute
  • Inlet Hopper
  • Collection Chamber

• Rounding Off (Clause 0.3):
  Values from tests or calculations must be rounded as per IS 2:1960.

  • Retain the same number of significant figures as in the specified standard value.

Key Definitions Summary

Rounding Rule (IS 2:1960)

• Round off final values to the same decimal or significant figures as the specified value.

If you need formulas or tables for design parameters (e.g., chute slope, hopper angles), please specify!

IS 6924: General Requirements Summary

• Scope (Clause 2.1):
  Covers design, construction, and location of chute systems, including:

  • Chute
  • Inlet hopper
  • Collection chamber

• Material Specifications (Clause 4.2.4):

  • Door, head, frame, and receiving unit made of mild steel, cast iron, or aluminium.
  • Components must be corrosion protected.
  • Door:
    • Self-closing mechanism
    • Secure latch
    • Rubber gasket for gas tightness and noise reduction
  • Receiving plate:
    • Two retaining side plates to prevent spillage

• Rounding Off (Clause 0.3):
  Results of tests or calculations must be rounded as per IS:2-1960, maintaining the same significant figures as specified values.

Key Design Notes:

flowchart LR
    A[Inlet Hopper] --> B[Chute]
    B --> C[Collection Chamber]
    C --> D[Receiving Plate with Side Plates]
    D --> E[Door with Rubber Gasket & Latch]

This ensures safe, efficient, and noise-minimized chute operation per IS 6924.

IS 6924: Types of Refuse Chute Systems – Key Points

1. Number of Chutes (Clause 3.1)

• Depends on user convenience and quantity of refuse between two clearings.
• Refer to Appendix A for calculating refuse quantity from residential buildings.

2. System Description (Clause 1.1)

• Vertical pipe system with inlets at each floor.
• Refuse travels down to a collection chamber for periodic clearing.
• Designed for sanitary transport and collection.

3. Capacity & Dimensions (Clause 5.2)

• Capacity per family/apartment: Minimum 0.054 m³/day.
• Collection chamber size (minimum):
  • Length: 1.2 m
  • Width: 1.2 m
  • Height: 1.8 m
• If using wheeled containers:
  • Allow 15 cm clearance between containers.
  • Chute bottom should be 30 cm above container top to prevent spillage.
  • Minimum 2 m headroom for easy access.

Summary Table: Collection Chamber Dimensions & Capacity

flowchart TD
    A[Flats] -->|Refuse Inlet| B[Vertical Refuse Chute]
    B --> C[Collection Chamber]
    C -->|Clearing & Disposal| D[Refuse Containers / Trolleys]

This system ensures hygienic, convenient refuse disposal in multistoreyed residential buildings per IS 6924.

IS 6924: Individual or Combined Chute Systems

Key Points from Clause 3.2:

• Individual System: Each flat has an independent hopper serving the chute — maximizes user convenience.
• Combined System: A common hopper per floor serves multiple flats; the number of chutes depends on refuse quantity.

Design Considerations:

• Hopper capacity and number depend on the volume of refuse generated per floor.
• Chute dimensions must accommodate the refuse size and flow rate.
• Collection chamber size is based on total refuse expected.

Typical Specifications (based on IS 6924 and common practice):

Formula for Hopper Volume (approximate):

[ V = A \times h ] Where:

• (V) = volume of hopper (m³)
• (A) = cross-sectional area of hopper opening (m²)
• (h) = depth of hopper (m)

Flow Diagram of Systems:

flowchart LR
    A[Flats] -->|Individual Hopper| B(Individual Chute)
    B --> C(Collection Chamber)

    A -->|Common Hopper per floor| D(Common Hopper)
    D --> E(Combined Chute)
    E --> C

Summary:

• Individual systems prioritize convenience with one hopper per flat.
• Combined systems optimize space and cost by sharing hoppers per floor.
• Design parameters depend on refuse volume and user convenience.
• Follow IS 6924 for detailed dimensioning and installation guidelines.

IS 6924: Material of Construction - Key Points

• Chutes (Clause 3.3):

  • Constructed from asbestos cement or R.C.C. pipe with a smooth inside finish to ensure smooth flow of refuse.

• Collection Chamber (Clause 5.3):

  • Walls & roof: Brick masonry or any non-combustible material.
  • Door: Made of steel or fire-resistant material, fitted with rebates and reveals for gas-tightness.
  • Inner surfaces: Plastered with cement mortar for smooth finish; optionally lined with glazed tiles for ease of cleaning.
  • Junctions: Smoothly rounded to prevent dust lodging.

• Door, Frame, Receiving Unit (Clause 4.2.4):

  • Materials: Mild steel, cast iron, or aluminium, corrosion-protected.
  • Features: Self-closing door, secure latch, rubber gasket for gas tightness and noise reduction.
  • Receiving plate: Equipped with two retaining side plates to prevent spillage.

Summary Table of Materials

flowchart LR
    A[Chute] -->|Material| B[Asbestos Cement / RCC Pipe]
    C[Collection Chamber] -->|Walls & Roof| D[Brick Masonry / Non-combustible]
    C -->|Door| E[Steel / Fire-resistant]
    E -->|Features| F[Self-closing, Rubber Gasket]
    G[Receiving Unit] -->|Material| H[Mild Steel / Cast Iron / Aluminium]
    H -->|Protection| I[Corrosion Resistant]

For detailed design, ensure compliance with IS:2-1960 rounding rules for test values.

IS 6924: Location of Chutes – Key Points & Specifications

• Clause 3.6 Location:

  • Chutes can pass through service shafts with drainage pipes.
  • Location primarily depends on:
    • Position of inlet hopper (user convenience).
    • Position of collecting chamber.
  • Should be away from living rooms to minimize noise and odor nuisance.

• Clause 3.1 Number of Chutes:

  • Depends on user convenience and refuse quantity.
  • Refer Appendix A for calculating refuse quantity from residential buildings.

• Design Considerations:

  • Chutes, inlet hoppers, and collection chambers must be coordinated for ease of access and maintenance.
  • Noise and smell control is critical in location planning.

Typical Location Selection Criteria (Summary):

Diagram: Chute Location Concept

flowchart LR
    A[Inlet Hopper] --> B[Chute Shaft]
    B --> C[Collection Chamber]
    B -. Avoid near .-> D[Living Rooms]
    B --> E[Service Shafts with Drain Pipes]

Note: For detailed refuse quantity calculation and chute sizing, consult Appendix A of IS 6924.

IS 6924 - Key Specifications for Construction of Chute Pipes

• Diameter (Clause 3.4):
  Minimum internal diameter = 38 cm to avoid chokage and ensure smooth flow.

• Material (Clause 3.3):
  Use Asbestos Cement or R.C.C. pipes with a smooth inside finish for durability and flow efficiency.

• Construction (Clause 3.7):

  • Assemble chute pipes vertically.
  • Properly clamp to walls.
  • Joints made with cement mortar.
  • Embed chute squarely into surrounding walls for stability.

• Inner Surface Slope (Clause 4.2.3):

  • Hopper interior slope ≥ 45°, preferably 60° to horizontal for smooth refuse flow.
  • Smooth finish mandatory.
  • Y-connection may be used (materials: asbestos cement, cast iron, cement concrete pipe).

Summary Table

flowchart TB
    Hopper -->|Slope ≥45°| ChutePipe
    ChutePipe -->|Vertical, Clamped| Wall
    ChutePipe -->|Smooth Inside Finish| Flow
    Hopper -.->|Y-Connection| ChutePipe

This ensures a choke-free, durable, and efficient chute system as per IS 6924.

Ventilation Specifications from IS 6924

• Ventilation Pipe:

  • Full bore pipe at the upper end of the chute (above the topmost floor).
  • Pipe must extend 2 to 2.5 m above the roof or terrace.
  • Fitted with an umbrella-type cowl with wire mesh to prevent rain and debris ingress.

• Mechanical Ventilation:

  • Recommended for high-rise buildings.
  • Should be of the exhaust type to remove gases and odors effectively.

Key Points:

• Ventilation ensures gas-tightness and reduces odor.
• Proper sealing with rubber gaskets on doors prevents gas leakage.
• Smoothly rounded junctions in chambers prevent dust accumulation.

Summary Table:

flowchart TD
    Chute --> VentilationPipe
    VentilationPipe -->|2-2.5 m above roof| Roof
    Roof --> Cowl[Umbrella Cowl with Wire Mesh]
    HighRiseBuilding --> MechanicalVentilation[Exhaust Type Mechanical Ventilation]

This ensures proper airflow, odor control, and safety in refuse chute systems.

IS 6924 - Maintenance and Cleaning: Key Points

1. Maintenance of Chutes (Clause 3.9)

• Flushing: Provide a Y-connection at terrace level for water hose attachment to flush and clean the chute.
• Periodic Cleaning: Necessary to prevent blockages and maintain hygiene.

2. Cleaning and Maintenance Facilities (Clause 5.4)

• Water Tap: Install a water tap near the collection chamber.
• Drainage: Provide drainage with a trapped gully for waste water disposal during cleaning.

3. Access for Cleaning (Clause 5.7)

• Ensure easy access for cleaners and refuse collectors.
• Provide a well-paved pathway from the nearest road to the collection chamber for smooth refuse transport.

4. Refuse Quantity & Volume (Appendix A, Clause 3.1)

• Quantity of refuse: 680 g/capita/day (Bombay survey average)
• Density of refuse: 240 kg/m³
• Volume of refuse per capita/day:

[ \text{Volume} = \frac{680 \text{ g}}{1000 \times 240 \text{ kg/m}^3} = 0.00283 \text{ m}^3/\text{capita/day} ]

Summary Table:

flowchart LR
    TerraceLevel -->|Y-connection| Chute
    WaterTap --> Chamber
    Drainage --> Chamber
    Road -->|Paved Pathway| Chamber
    Cleaners --> Chamber

This ensures hygienic, efficient refuse disposal with ease of maintenance.

IS 6924: Inlet Hopper Design Key Points

• Height of Hopper:

  • Minimum 75 cm from floor to lower edge of inlet opening (Clause 4.2.2).

• Inner Surface Slope:

  • Interior slope towards main chute at angle ≥ 45°, preferably 60° for smooth refuse flow (Clause 4.2.3).
  • Surface must be smooth to avoid lodging of refuse.

• Construction Requirements:

  • Hopper door and frame must be fire-resistant (Clause 4.2).
  • Design to minimize escape of odour/vapour when door is open or closed.
  • Typical construction shown in Fig. 2 (not provided here).

Recommended Hopper Slope Angle:

Summary Diagram of Hopper Slope and Height:

flowchart TD
    Floor -->|75 cm| HopperInlet[Inlet Opening]
    HopperInlet -->|Slope 45°-60°| MainChute[Main Chute]
    style HopperInlet fill:#f9f,stroke:#333,stroke-width:2px

Note: Smooth, fire-resistant materials like asbestos cement, cast iron, or cement concrete pipes may be used for the inner surface or Y-connection.

This ensures efficient flow, safety, and hygiene in waste chute systems per IS 6924.

IS 6924 Key Specifications & Details for Door, Head, Frame, and Receiving Unit

• Materials: Mild steel, cast iron, or aluminium with corrosion protection (Clause 4.2.4).
• Door Design:
  • Self-closing mechanism with counterbalance (Clause 4.2.5).
  • Secure latch for firm closure.
  • Rubber gasket between door and frame for gas tightness and noise reduction.
• Receiving Plate:
  • Fitted with two retaining side plates to prevent spillage (Fig. 2 reference).
• Hinge (Clause 4.2.6):
  • Smooth edges, user-safe.
  • Removable door for maintenance.
• Handle (Clause 4.2.7):
  • Properly fixed for easy operation.

Typical Design Considerations:

flowchart LR
    Door -->|Self-closing| Frame
    Door -->|Latch| Frame
    Door -->|Rubber Gasket| Frame
    ReceivingPlate -->|Side Plates| PreventSpillage
    Hinge -->|Smooth & Removable| Door
    Handle -->|Fixed| Door

Note: For detailed dimensions and load calculations, refer to IS 6924 annexures or design tables specific to door sizes and materials.

IS 6924: Collection Chamber - Key Specifications & Formulas

1. Minimum Collection Chamber Size

• 1.2 m (W) x 1.2 m (D) x 2 m (H)
• This size is the minimum requirement when containers are used.

2. Container Specifications

• Diameter = 0.9 m
• Height = 1.3 m
• Capacity ≈ 0.826 m³
• Volume of refuse per clearing = 0.54 m³
• Number of containers per chute = 1

3. Refuse Volume Calculation (Appendix A, Clause 3.1)

• Quantity of refuse = 680 g/capita/day
• Density of refuse = 240 kg/m³
• Volume of refuse per capita per day:
  [ \text{Volume} = \frac{680 \text{ g}}{1000 \times 240 \text{ kg/m}^3} = 0.00283 \text{ m}^3/\text{capita/day} ]

4. Design Considerations

• Chamber designed for 2 days of refuse to allow for irregular municipal cleaning.
• For multiple chutes (e.g., 2 chutes), scale volume accordingly.
• Provide easy access with paved pathways for cleaners and refuse collectors (Clause 5.7).

Summary Table

flowchart TD
    A[Domestic Refuse] --> B[Calculate Volume per Capita]
    B --> C[Determine Number of Chutes]
    C --> D[Select Container Size]
    D --> E[Design Collection Chamber]
    E --> F

IS 6924 - Location Guidelines for Garbage Chutes

• Clause 5.1:

  • The collection chamber must be located at ground level for ease of access and maintenance.

• Clause 3.6:

  • The chute can be routed through service shafts designed for drainage pipes.
  • Location depends primarily on:
    • Position of the inlet hopper (user convenience).
    • Position of the collection chamber (ground level).
  • Avoid placing chutes near living rooms to minimize noise and odor nuisance.

Summary Table:

flowchart TD
    A[Inlet Hopper] --> B[Chute in Service Shaft]
    B --> C[Collection Chamber at Ground Level]
    style C fill:#f9f,stroke:#333,stroke-width:2px
    note right of B
      Avoid near living rooms
      to reduce noise & smell
    end

This ensures functionality, hygiene, and user convenience as per IS 6924.

IS 6924: Construction and Finishing Key Points

• Walls & Roof: Constructed with brick masonry or any non-combustible material.
• Door: Made of steel or fire-resistant material with proper fittings including rebate and reveals to prevent gas/fume escape.
• Surface Finish: Inner walls, floor, and ceiling plastered with cement mortar for a smooth finish.
• Optional Lining: Use glazed tiles for easier cleaning and maintenance.
• Junctions: Smoothly rounded off at wall-to-wall and wall-to-floor junctions to avoid dust accumulation.

Material Specifications for Chutes (Clause 3.3)

• Constructed from asbestos cement or R.C.C. pipes with a smooth inside finish to facilitate refuse movement.

Typical Construction Details (Fig. 2)

• Cast Iron Frame for inlet hopper.
• Smooth rendering on surfaces to prevent dust lodging.

Summary Table: Construction Materials

flowchart TD
    A[Refuse Chute System] --> B[Inlet Hopper]
    A --> C[Chute]
    A --> D[Collection Chamber]
    B --> E[Cast Iron Frame]
    C --> F[Asbestos Cement / RCC Pipe]
    D --> G[Brick Masonry Walls]
    G --> H[Cement Mortar Plaster]
    H --> I[Glazed Tiles (Optional)]

This ensures fire safety, hygiene, and smooth refuse flow per IS 6924.