Basic regulations for construction quality acceptance of ventilation and air conditioning projects

1. The acceptance of the construction quality of ventilation and air-conditioning projects, in addition to complying with the provisions of this specification, shall also be carried out in accordance with the approved design drawings, the contents of the contract and the provisions of relevant technical standards. The modification of construction drawings must be accompanied by a design change notice or technical verification visa from the design unit.

Note: This article outlines the acceptance criteria for ventilation and air-conditioning project construction, which include approved design drawings and relevant technical standards. Adhering to the approved designs is essential for quality acceptance, and modifications to the design must follow formal procedures to ensure project quality. The technical standards encompass agreed-upon construction and quality acceptance guidelines, including this specification and applicable national, industry, local, and enterprise standards. This specification and national standards represent the minimum requirements, while higher standards may also be adopted in construction.

(Figure 1: Ventilation and air conditioning engineering construction)

2. The construction enterprise that undertakes the ventilation and air-conditioning project should have the corresponding qualification level for engineering construction contracting and the corresponding quality management system.

Note: Ventilation and air-conditioning projects vary significantly in scope and complexity. While international standards may not enforce strict qualifications for contractors, China's construction market effectively categorizes companies by capability to ensure quality in engineering management and construction.

3. When construction companies undertake the in-depth design and construction of ventilation and air-conditioning engineering construction drawings, they must also have the corresponding design qualifications and their quality management system, and should obtain the written consent or signed approval of the original design unit.

Note: With the further development of my country's construction market economy, the construction contracting of ventilation and air-conditioning engineering will gradually move closer to international practices. At present, a few large and medium-sized construction companies with considerable technical foundations have the ability to deepen construction drawings and carry out construction in accordance with international practices, but most medium and small construction units do not have this ability. 

4. The quality management of the construction site of ventilation and air-conditioning projects shall comply with the "Uniform Standard for Construction Quality Acceptance of Building Projects".

(Figure 2: Ventilation and air conditioning project construction site)

Note: In the "Uniform Standard for Construction Quality Acceptance of Building Projects" GB 50300-2001, all the contents of the quality management of the construction site of building projects have been clearly stipulated, and this specification directly quotes it.

5. The main raw materials, finished products, semi-finished products and equipment used in ventilation and air-conditioning projects must be inspected upon entry. The acceptance should be approved by the supervision engineer and the corresponding quality records should be formed.

Note: The quality of the main raw materials, finished products, semi-finished products and equipment used in ventilation and air-conditioning projects will directly affect the overall quality of the project. Therefore, this specification stipulates that after entering the construction site, it must be inspected in kind. The acceptance should generally be jointly participated by representatives of suppliers, supervisors and construction units. The acceptance must be approved by the supervision engineer and documented.

6. In the construction of ventilation and air-conditioning projects, each sub-construction process should be used as a process handover inspection point, and corresponding quality records should be formed.

Note: Ventilation and air-conditioning projects have different contents and requirements for each specific project. This article, based on the actual construction, compels the construction enterprises that undertake ventilation and air-conditioning projects to formulate corresponding technical measures for processes and documents according to the pending projects under construction, and stipulates that after the sub-projects and the processes required to be verified in the provisions of this specification are completed, they should be used as the handover points for process inspection, and corresponding quality records should be kept. This provision emphasizes the quality control of the construction process and the traceability of the quality of the construction process, and should be implemented.

(Figure 3: Ventilation and air conditioning engineering construction equipment)

7. If errors are found in the design documents during the construction of ventilation and air-conditioning projects, modification opinions or correction suggestions should be put forward in a timely manner, and written documents should be formed and archived.

Note: This article is a requirement for construction companies. During the construction of ventilation and air-conditioning projects, it is normal for construction personnel to find problems and partial errors in the implementation of engineering construction drawings. We require that the situation be reflected and corrected in time according to formal procedures, and the documents be filed, which is in line with the basic provisions of project management. It should be noted here that the pre-examination of the construction drawings is very important and should be advocated.

8. When the ventilation and air-conditioning project is constructed as a sub-project of the construction project, the division of its sub-divisions and sub-projects should be carried out according to the provisions of the table. When the ventilation and air-conditioning project is independently accepted as a unit project, the sub-division is promoted to a sub-division, and the division of the sub-project is the same as above.

Note: The ventilation and air-conditioning project is divided into seven sub-projects for easier supervision and quality acceptance. Each sub-project is listed, and when contracted independently, the ventilation project becomes a unit project, maintaining its original content.

9. The construction of ventilation and air-conditioning projects should be carried out according to the prescribed procedures and cooperate with civil engineering and other professional works; after the construction of civil engineering related to ventilation and air-conditioning systems is completed, it should be jointly inspected by the construction or general contractor, supervision, design and construction units. The organization of the joint inspection should be the responsibility of the construction, supervision or general contractor.

Note: This article mandates that ventilation and air-conditioning projects follow prescribed construction procedures and collaborate with civil engineering. Quality handover inspections are essential for confirming prior work quality and clarifying responsibilities, ensuring effective project quality management and implementation.

(Figure 4: Ventilation project quality acceptance)

10. The acceptance of the construction quality of the sub-projects of ventilation and air-conditioning projects shall be carried out in accordance with the specific provisions of the corresponding sub-items of this specification. Each sub-item in the sub-division can be accepted once or several times according to the actual situation of the construction project.

Explanation: This article is a regulation for the acceptance of sub-projects of ventilation and air conditioning engineering. This specification is written in sub-items according to the content of the same construction process. The same sub-item may contain regulations for similar processes in different sub-divisions. Therefore, when executing, it must be carried out in accordance with the detailed content of the specific articles in the corresponding sub-items of the specification.

11. Concealed works in ventilation and air-conditioning projects must be inspected and approved by supervisors.

Note: When the air ducts or pipes in the ventilation and air-conditioning engineering system are installed in closed areas or buried in structures or directly buried in the ground, they are all concealed works. Before the structure is permanently closed, the construction quality of the concealed air duct or pipe engineering must be inspected and accepted, and must be approved by the on-site supervisor, otherwise the closed operation shall not be carried out.

(Figure 5: Composite material air duct)

12. Welders engaged in pipeline welding construction in ventilation and air-conditioning projects must have operation qualification certificates and assessment certificates for corresponding types of pipeline welding.

Note: In the construction of ventilation and air-conditioning projects, welding connection of metal pipes is one of the conventional construction processes. The quality of pipeline welding will directly affect the safe use of the system and the quality of the project. According to the "Construction and Acceptance Specifications for Field Equipment and Industrial Pipeline Welding Projects" G8 50236-98, the welder qualification regulations stipulate that "to engage in corresponding pipeline welding work, you must have a certificate of qualification for the corresponding welding method examination project and it must be valid." 

13. The system commissioning of the completed ventilation and air-conditioning project should be carried out with the joint participation of the construction and supervision units. The construction company should have professional inspection personnel and test instruments that meet the relevant standards. 

Note: The system commissioning of the completed ventilation and air-conditioning project is part of the project construction. It is the process of correctly adjusting the completed project system until it meets the design requirements. At the same time, system commissioning is also a process of comprehensive inspection of the quality of project construction. Therefore, this article emphasizes the joint participation of the construction and supervision units, which can not only play a supervisory role, but also improve the comprehensive understanding of the project system, which is conducive to the management of future operations.

(Figure 6: Ventilation and air conditioning engineering inspection)

14. The system debugging at the completion stage of ventilation and air-conditioning projects is a job with high technical requirements. It must have corresponding professional technicians and testing instruments. Otherwise, it is impossible to complete this work well and achieve the expected results. 

Therefore, this article makes clear provisions. The warranty period for the construction quality of ventilation and air-conditioning projects is calculated as two heating periods and cooling periods from the date of completion acceptance. If construction quality problems occur during the warranty period, the construction company shall perform the warranty duties, and the responsible party shall bear the corresponding economic responsibility.

Note: The warranty period for ventilation and air-conditioning projects is two heating and cooling periods. Issues arising during this time must be investigated, responsibilities clarified, and rectifications made, ensuring accountability for economic losses while improving industry design and construction quality.

(Figure 7: Cleanliness level detection)

15. The cleanliness level of the clean room (area) of the purification air conditioning system shall meet the design requirements. The detection of the cleanliness level shall be in accordance with the provisions of this specification, and the provisions of the cleanliness level and the maximum concentration limit of suspended particles in the air (Cn).

Note: This article is the division of the cleanliness level of the purification air conditioning system, and the provisions of the standard shall be implemented. In the past, my country's division of the clean room level of the purification air conditioning system was implemented in accordance with 209b, which can no longer meet the needs of the current development of clean room technology. The standard now adopted is the provisions of the newly revised "Clean Plant Design Code" GB50073-2001, which is consistent with the division of international standards. The construction, commissioning and quality acceptance of the project should be unified with this standard.

16. The acceptance quality of the sub-project inspection batch shall comply with the following provisions:

• There shall be an acceptance record of the corresponding sub-item qualified quality of the construction unit;

• The quality sampling inspection of the main control project shall be fully qualified.

• For the quality sampling inspection of general projects, except for special requirements, the counting qualified rate shall not be less than 80%, and there shall be no serious defects.