In building HVAC and equipment insulation projects, anti-condensation performance is one of the important indicators for evaluating the practicality of insulation materials. Glass wool is widely used for duct, pipe, and equipment insulation, and it has certain advantages in preventing condensation, but it also depends on construction conditions. The following analysis examines the anti-condensation performance of glass wool from the perspectives of mechanism, advantages, and limitations.

Firstly, from the perspective of the anti-condensation mechanism, glass wool is a porous fiber insulation material, its interior composed of a large number of interwoven fine fibers forming a still air layer. Air itself has a low thermal conductivity; glass wool reduces the rate of heat transfer from the cold surface to the outside, keeping the outer surface temperature above the air dew point temperature, thus reducing the likelihood of condensation. This anti-condensation capability is based on a reasonable match between material thickness and thermal conductivity.

Secondly, the anti-condensation effect of glass wool in conventional HVAC systems is relatively stable. In conditions such as air conditioning supply and return ducts, as long as the insulation thickness meets design requirements, glass wool can effectively control the outer surface temperature of the pipes or ducts, preventing surface condensation. This is one of the key reasons why glass wool has been widely used in HVAC systems for so long.

Third, its anti-condensation performance is highly dependent on the moisture barrier. Glass wool itself does not have a closed-cell structure; once moisture enters the fibers, it not only reduces the insulation effect but also destroys the original anti-condensation conditions. Therefore, in practical engineering, glass wool usually needs to be used in conjunction with moisture barriers such as aluminum foil or fiberglass cloth. The continuity and sealing quality of the moisture barrier often determine the anti-condensation effect more directly than the glass wool itself.

Fourth, the anti-condensation performance of glass wool has certain limitations under high humidity or low temperature conditions. When the ambient humidity is high or the pipe surface temperature is extremely low, if the moisture barrier is damaged, the joints are not tight, or the construction is not up to standard, moisture can easily seep in through the joints, leading to internal condensation or even frost. This type of problem is particularly common in systems such as chilled water pipes and refrigerant pipes.

Fifth, the quality of construction has a significant impact on anti-condensation. If the glass wool is compressed during installation, the effective thickness will be reduced, thereby reducing the ability to control the external surface temperature and increasing the risk of condensation. Meanwhile, loose seams and inadequate finishing of details such as corners and flanges can easily create cold bridges, becoming high-risk areas for condensation.

In summary, glass wool possesses good basic performance in preventing condensation, but its effectiveness is highly dependent on the moisture-proofing design and construction quality. Provided that the correct type is selected, sufficient thickness is achieved, a continuous moisture-proof layer is in place, and detailed sealing is performed properly, glass wool can meet the condensation prevention requirements of most HVAC systems. However, under high humidity or extremely low temperature conditions, it needs to be combined with other materials or enhanced protective measures to ensure long-term stable operation.