What are the differences between double-layer box boards and single-layer box boards used in air-conditioning boxes?

Double-layer panels are usually composed of inner and outer panels and an intermediate insulation layer, while single-layer panels require additional evaluation of insulation, condensation and internal surface treatment. The selection should be based on the air supply temperature, ambient temperature and humidity, cleaning requirements and mechanical structure. The difference between the two cannot be summarized by 'double layer is thicker'.

Let’s first look at the structural differences, not just the thickness

Double-layer box panels are generally composed of outer steel plates, inner panels and intermediate insulation core materials. The inner and outer surfaces face the environment and the air in the box respectively. Single-layer box panels usually have only one metal plate, and the insulation layer may be externally attached or constructed in another way. The performance of the two is different in terms of thermal insulation continuity, inner surface flatness, seam treatment and mechanical strength, and the total thickness cannot be compared only.

Construction differences also affect box weight, lifting and shipping staging. Double-layer box boards are usually heavier and require higher requirements on frames and lifting points; single-layer box boards are lighter, but the insulation and condensation risks need to be dealt with separately. What indicators should be used to determine the thickness of the air conditioning box board? Please refer toWhat indicators should be used to determine the thickness of air conditioning box panels?。

The inner and outer surfaces and insulation layer of double-layer box panels

The inner panel of a double-layer box panel is usually flat and easy to clean, the outer panel plays a role in protection and appearance, and the middle insulation layer reduces heat exchange. The connection method between the inner and outer surfaces, insulation material sealing and thermal bridging treatment determine the actual insulation effect. If the frame and fasteners are not heat-insulated, condensation may still occur locally.

Double-layer box panels also need to check whether the inner panel material meets the requirements for cleanliness and corrosion resistance, and whether the insulation core material can adapt to the supply air temperature and humidity. Insulation that gets damp will reduce its effectiveness and may cause internal corrosion. Please refer toHow to judge whether the retained box is suitable before rebuilding the old air-conditioning box?。

Applicable conditions and risks of single-layer box boards

The single-layer box board has a simple structure and light weight, and is suitable for occasions where the air supply temperature is close to the environment and the temperature and humidity requirements are not high. If used in a low-temperature air supply or high-humidity environment, the outer surface temperature of the single-layer board may be lower than the dew point and condensation may occur. At this time, additional insulation, moisture-proof layer or thermal bridge treatment is required, otherwise condensation may drip or cause corrosion.

The interior surface preparation and cleaning accessibility of single-wall panels also need to be evaluated. If the box needs to be cleaned regularly, the way the joints, fasteners and insulation of the single-layer panels are exposed may affect the cleaning effect. How to make requirements for internal cleaning accessibility of biomedical air-conditioning boxes, please refer toWhat are the requirements for internal cleaning accessibility of biomedical air-conditioning boxes?。

Insulation, condensation and thermal bridging should be looked at holistically

Whether double-layered or single-layered, the insulation effect doesn't just depend on the thickness of the board. Thermal bridges in frames, door frames, hanging points, pipes and joints may become localized condensation points. When the insulation material gets damp, the thermal conductivity increases and the effect decreases. The box plate, frame, sealing and thermal insulation structure should be checked together during design.

Noise propagation is also related to the box structure. Double-layer box boards usually have a certain inhibitory effect on box radiation noise, but they cannot replace special noise reduction and vibration reduction measures. Please refer toWhat noise propagation paths should we pay attention to when selecting an air-conditioning box?。

Sealing, Cleaning and Maintenance Differences

The joints and door frames of double-layer box panels usually have a more complete sealing structure, but there are many joints and fasteners, and the installation quality still affects the air tightness. Single-layer box panels have fewer seams, but rely on additional construction for insulation and sealing. Both need to check the sealing of access doors, filter mounting frames and pipe penetrations.

Under what pressure conditions should the box air leakage rate be compared? Please refer toUnder what pressure conditions should the air leakage rate of air conditioning boxes be compared? . In terms of cleaning and maintenance, the inner surface flatness of double-layer box panels is usually better, but if the insulation layer is exposed or damp, cleaning will be more difficult.

How to write procurement documents clearly

The procurement documents should state the inner and outer panel materials, insulation core material and thickness, frame form, sealing method, condensation conditions and cleaning requirements, instead of just 'double-layer box board' or 'single-layer box board'. It is also necessary to indicate the operating pressure, supply air temperature, ambient temperature and humidity and acceptance method.

What applicable standards should be listed in the technical documents for purchasing air-conditioning boxes? Please refer toWhat applicable standards should be listed in the technical documents for purchasing air-conditioning boxes? . How to choose between combined and integral types, please refer toHow to choose between combined and integrated air conditioning boxes?。

Aili industrial supporting equipment

Aili Industrial can combine sheet metal and complete machine assembly to check the box structure, and recommends that insulation, cleaning and maintenance requirements be included in the structural technical conditions. Aili's industrial manufacturing end covers the independent research and development and production of motors and fans, control systems, sheet metal, air filters and complete machine assembly. The box plate structure, frame form and sealing method can be matched in the same set; non-standard boxes can be adjusted according to the on-site environment and transportation conditions.

Product form can be viewedAir handling unit andFan box page; clean air supply package can be combinedFFU fan filter unit andEFU equipment end fan filter unit verification; terminal particle filtration can be combinedHEPA/ULPA filter confirmation; when it comes to gaseous pollution control, you can communicate separatelyChemical filter solutions. The specific box performance, applicable environment and delivery scope still need to be verified based on the corresponding configuration data and on-site working conditions. Actual results are subject to on-site inspection and performance test results.

Submit project parameters:https://ailigy.com/contactus.html

Related questions and answers

Is a double-layer box board better than a single-layer box board in terms of insulation?
uncertain. The insulation effect also depends on the core material, thickness, seams and thermal bridging treatment, not just the number of layers.

Can single-layer box boards be used for low-temperature air supply?
Additional evaluation of insulation and anti-condensation measures is required. If the outer surface temperature is lower than the dew point, condensation may occur on the single-layer board, and heat insulation or insulation treatment should be performed.

Can Aili Industrial help choose the form of box panels?
The double-layer or single-layer solution can be checked based on the air supply temperature, ambient humidity, cleaning requirements and structural conditions. The specific configuration needs to be confirmed based on the project conditions.

Related articles

1. What indicators should be used to determine the thickness of air conditioning box panels?

2. Under what pressure conditions should the air leakage rate of air conditioning boxes be compared?

3. How to judge whether the retained box is suitable before rebuilding the old air-conditioning box?

4. What noise propagation paths should we pay attention to when selecting an air-conditioning box?

Key points for selection and acceptance inspection