GB 50738-2011Code for construction of ventilation and air conditioning (English PDF)

2.0.1 Air duct

A duct, made from metal, nonmetallic sheet or other material, for ventilation.

2.0.2 Nonmetallic duct

Air duct made from such nonmetallic materials as rigid PVC and glass reinforced plastic (GRP).

2.0.3 Composite duct

Air duct made from the compositing of incombustible surface course and thermal-insulating inner plate.

2.0.4 Air channel

A channel, made from such building materials as concrete and brick, for ventilation.

2.0.5 Duct fittings

Elbow, tee, cross, reducer, special tube, guide vane and flange used in the air duct system.

2.0.6 Duct component

Air opening, valve, hood, cowl, muffler and filter involved in the air duct system.

2.0.12 Strength test

Test on the pressure resistance of pipeline, pressure vessel, valve and accessory within specified pressure and pressure holding time.

2.0.13 Leakage test

Test on the leakage of pipeline, pressure vessel, valve and accessory within specified pressure and pressure holding time.

3.1 Construction Technology Management

3.1.1 The enterprise which undertake the construction of ventilation and air conditioning shall have appropriate construction qualification. And appropriate technical standards shall be available for the construction site.

3.1.5 The change of construction drawings need be approved by the original design organization.

Where the change of construction drawings involves in the using and energy-saving effects of ventilation and air conditioning, such change shall be subject to review by the censorship of the original construction drawing design documents. Before any change is made, relevant procedures shall be handled and confirmation by the supervision and development organizations is required.

3.1.6 Before system check and test as well as operation and commissioning, the construction

organization shall prepare appropriate technical schemes and subject them to review and approval.

3.2 Construction Quality Management

3.2.1 Appropriate quality management system shall be established for the construction site of ventilation and air conditioning and shall cover the following content.

3.2.3 Where the pipeline crosses wall and floor slab, sleeve shall be arranged according to the design requirements, and flame retardant material shall be used between sleeve and pipeline for compact filling;

where the pipeline crosses fire compartment, incombustible material shall be used for fireproof plugging.

3.2.4 Before connecting pipeline and equipment, the system pipeline shall pass the hydrostatic test and flushing (purging) test.

4.1 General Requirements

4.1.1 Mature technology and process as well as high-efficient, low-consumption and low-labor-

intensity should be selected for metal duct and fittings making.

4.1.4 Before the air duct making for clean air conditioning system, soft fabrics shall be used to wipe the plates so as to clean up the contaminants and fats on their surfaces. After completion of such making, neutral detergent shall be timely used to clean up them, mercerized cloth shall be used to wipe the inside of air duct, and plastic film shall be used to seal the port of air duct.

4.1.6 The minimum thickness of steel plates for rectangular duct and fittings shall be selected according to the long side dimension of air duct segment and the design operating pressure of air duct system, and shall be in accordance with those specified in Table 4.1.6-1; the minimum thickness of steel plates for circular duct and fittings shall be selected according to the diameter of section, the design operating pressure of air duct system and the form of bite, and shall be in accordance with those specified in Table 4.1.6-2.

4.1.8 Before bulk processing of air duct, the processing technique shall be verified, and strength and leakage test shall be carried out.

4.2 Metal Duct Making

4.2.1 The metal duct shall be made according to the following procedures (Figure 4.2.1).

Figure 4.2.1 Metal Duct Making Procedures

4.2.2 The plates or profiles shall be selected according to the construction drawings and relevant technical documents; moreover, the selected materials shall be re-inspected and shall meet the requirements of Article 4.1.6 in this code.

5.1 General Requirements

5.1.1 The fire-proof performance of nonmetallic or composite duct material shall comply with the design requirements and the current relevant national standards.

5.1.4 The making method of nonmetallic or composite duct shall be determined according to the connection type of air duct. The connection type and application scope of nonmetallic or composite duct shall be in accordance with those specified in Table 5.1.4.

5.2.3 The air duct bonding and forming shall meet the following requirements.

5.2.5 The strengthening and guide vane installation shall meet the following requirements.

5.3 Glass Fiber Composite Duct and Fittings Making

5.3.1 The glass fiber composite duct and fittings shall be made according to the following procedures (Figure 5.3.1).

5.3.5 The air duct strengthening and guide vane installation shall meet the following requirements.

6.1 General Requirements

6.1.1 The materials for making air valve and components shall meet the requirements of design and relevant technical documents.

6.1.2 The finished air valve and components in use shall have acceptable quality certificates.

6.2 Air Valve

6.2.1 The quality of finished air valve shall meet the following requirements.

6.2.4 The fire valve and smoke discharge valve (smoke vent) shall meet the requirements of the relevant national current technical standards on fire protection products. Operation test shall be carried out on the actuating mechanism and the test result shall meet the requirements of product specifications.

6.3 Hood and Cowl

6.3.1 The hood and cowl shall be made according their types and service requirements. After sampling the selected materials based on the construction drawing, they may be prepared and processed by biting and welding. The making method may be in accordance with the requirements of Chapter 4 in this code.

6.4 Air Opening

6.4.1 The finished air opening shall have sound construction and smooth outside external surface; its vane shall be distributed uniformly without consistent color and free from scratch and deformation.

Moreover, it shall meet the requirements of product technology standards. Its surface shall be subject to anti-corrosive treatment and shall meet the design and service requirements. The air opening shall be able to rotate flexibly and reliably. After positioning, it shall be free from any looseness.

7.1 General Requirements

7.1.1 The fixing mode of trestle and hanger and the use of fittings shall meet the design requirements and shall meet the following requirements.

7.1.2 The embedded parts of trestle and hanger shall be correctly, firmly and reliably positioned. The embedded structure shall be de-rusted and degreased and shall not be painted. The exposed part shall be subject to anti-corrosive treatment.

7.1.4 The finished product protection measures for the making and installation of trestle and hanger shall cover the following items.

7.2 Trestle and Hanger Making

7.2.1 Before trestle and hanger making, the following construction requirements shall be met.

7.2.3 The type of trestle and hanger shall be determined according to the building structure and fixing position, and shall meet the design requirements.

7.3 Trestle and Hanger Installation

7.3.1 Before trestle and hanger installation, the following construction requirements shall be met.

7.3.2 The trestle and hanger be installed according to the following procedures (Figure 7.3.2).

Figure 7.3.2 Trestle and Hanger Installation Procedures

7.3.3 The type, specification and position of embedded parts shall meet the design requirements and shall be cast into a whole body with structure.

7.5 Quality Inspection

7.5.1 The quality of trestle and hanger may be inspected according to those specified in Table 7.5.1.

8.1 General Requirements

8.1.1 Before air duct and components installation, the following construction requirements shall be met.

8.1.2 When the air duct crosses fire-proof and explosion-proof floor slab or wall to be enclosed, steel embedded duct or protective sleeve with wall thickness not less than 1.6mm shall be arranged.

Incombustible flexible material with no harm on human body shall be applied between air duct and protective sleeve for blockage.

8.1.4 The sealing material connected with air duct shall be selected according to the temperature of transmission medium and shall meet the function requirements of air duct system; moreover, its fire-proof performance shall meet the design requirements.

8.1.9 Rain-proof device shall be arranged where the air duct projects out of the roof. Anti-seepage measures shall be taken at the connection of air duct and roof (Figure 8.1.9).

8.1.10 The installation position of air supply and return openings of fan coil shall meet the design requirements. Where there is no requirement in the design, the spacing between air supply and return openings in the same plane should not be less than 1200mm.

8.3 Nonmetallic or Composite Air Duct Installation

8.3.1 The nonmetallic or composite air duct shall be installed according to the following procedures (Figure 8.3.1).

8.3.2 Before air duct installation, its installation position shall be measured and located to determine the center line of pipeline.

8.3.5 The nonmetallic duct connection shall meet the following requirements.

8.3.6 Socket step bonding, inserter connection or flange connection should be adopted for composite duct. The air duct shall be firmly and tightly connected and shall meet the following requirements.

8.7 Installation of Muffler, Static Pressure Box, Filter and Heater in Air Duct

8.7.1 During muffler and static pressure box installation, trestle and hanger shall be arranged

separately and shall be firmly fixed.

8.7.2 Where the muffler and static pressure box are connected with metal duct, the flange shall match.

9.1 General Requirements

9.1.1 Before the installation of air handling equipment, the following requirements shall be met.

9.1.2 The transportation and hoisting of air handling equipment shall meet the following requirements.

9.1.4 Finished product protection measures of air handling equipment installation shall include the following contents.

9.2 Air Conditioning Terminal Device Installation

9.2.1 Air conditioning terminal device installation includes the installation of fan coil unit, induction unit, VAV air conditioning terminal device and direct-evaporating indoor air conditioner.

9.2.2 Air conditioning terminal device installation shall be carried out according to the following procedures (Figure 9.2.2).

9.4.4 Where hoisting installation is adopted for equipment, the hanger and damping device shall meet the requirements of the design and relevant technical documents.

9.4.5 The site assembly of central-station air handling unit and heat recovery device shall be conducted by the supplier; the air leakage ratio test shall be carried out after assembling and the air leakage ratio shall meet the requirements of the current national standard "Central-station Air Handling Units" GB/T 14294.