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The Six Criteria for Selecting Air Duct

小视频资源官网,现实农村美女生活照片1.Fire safety

According to GB50016-2014 Code for Design of Building Fire Protection, the fire resistance of the air duct shall be above class B2.

2.Environmental protection requirements

According to GB50243-2002 Code of Acceptance for Construction Quality of Ventilation and Air Conditioning Works, article 4.2.4 : “Material that is harmless to human beings”. Generally speaking, the most harmful components of decoration materials are formaldehyde, free benzene and other harmful substances that may be released into the air. When selecting the air ducts, we must eradicate these harmful substances, in order to eliminate the potential harm to personal health.

Special hint: the formaldehyde content of phenolic duct is around 12% to 15%; Benzene content in the polystyrene duct is severe exceeding of the standards; Glass magnesium air pipe (variant product of inorganic glass fiber reinforced plastic air duct) is susceptible to moisture and slag, etc, which we should be paid more attention to when selecting the air duct.

3.Energy saving requirements

小视频资源官网,现实农村美女生活照片According to GB50189-2015 Design Standard for Energy Efficiency of Public Buildings, appendix D, Thermal Insulation Thickness of Pipelines and Equipment, the minimum heat resistance of the insulation layer of indoor air conditioning ducts should be not less than 0.81 (m². K)/W.

If in accordance with the 20mm or 25mm thickness pre-insulated air duct which is popular in the present market, then the thermal conductivity of the core insulation layer must be less than 0.025 w/m.k or 0.031 w/m.k, Otherwise, it can’t meet the current design standards for energy saving. According to the GB50411-2007 Code for Acceptance of Energy Efficient Building Construction, unit engineering acceptance should be carried out after passing acceptance of part of the energy efficient building construction. That is, if using the pre-insulated air duct that is not up to the above-mentioned standards, it can’t pass the project acceptance.

According to current technology, except PIR and polyurethane (PUR) air ducts, all 20mm thick air ducts can’t be used. Except for thicken them to 25mm or 30mm.

According to the national energy-saving code, PIR energy-saving pre-insulated air duct should be listed as the first choice in the air duct industry. Since its thermal conductivity is very low.

4.Physical property

4.1The duct panel should have a certain strength and toughness to meet the requirements of air duct pressure.

Simple test method: raising at both ends of the duct panel which is in 4 meters long, jitter freely up and down, and the duct panel is without cracking, then it can be considered to meet the requirements. In general, the strength and toughness of pre-insulated air duct depend on the internal structure of the air duct. Phenolic duct panel belongs to independent molecular structure (powdery body), and glass fiber belongs to scattered structure, their strength and toughness are relatively poor. We should have to be very careful when choosing the air duct type.

4.2 The duct panel has good physical stability and can’t be deformed.

After a cold and summer cycle, the bonding strength between the surface layer and the core material remains good, no bubble, no shedding, no shrinkage, no pulverization. In general, if the surface layer compound adopts the drop glue technology, then the hidden danger is bigger, since the bubble will occur, or the surface layer will fall off easily. If inorganic materials (such as vitreous magnesium duct) are used in the surface layer, then special attention should be paid to the humidity of the place where the air duct is used, which is prone to moisture absorption, halogenation, pulverization and even slagging.

5.Functional requirements

5.1To ensure that the quality of air transport remains unchanged, air duct materials must not contain harmful substances, there can be no hidden danger of slag drop, no hidden danger of fiber escaping with the air, etc.

5.2To ensure that the air duct meets the design wind pressure, it requires that when the air duct system is in operation, the air inside the duct will not leak out or the air outside the duct will not intrude, the deformation of the air duct shall not exceed 20 mm, and the corner edge of the air duct shall not crack.

5.3To ensure that there is no cold bridge, no condensing water, the air duct panel is required to have a sufficiently low thermal conductivity. Also required that there is no weak link, no air leakage and no light leakage when the air duct is made.

5.4Conveying air does not produce noise or having the function of silencing.

5.5Reliable operation, long service life and simple maintenance.

6.Construction technology

Manufacturers should provide systematic and complete production and installation of air ducts to make sure the realization of the functional requirements of the air ducts.

Pre insulated | pir duct panel | pid duct panel