How to Check for the Best Mold Proof Designed HVAC Systems

Mold, fungi and mildew are some of the microbes that pose health hazards to you and your family. This means your HVAC systems must deal with these microbes in addition to providing you with indoor comfort. HVAC systems have for a long time played a key role in fighting the growth of mold in buildings by providing environmental conditions that are detrimental to their survival. However, not all systems can achieve this because a number of them lack the essential features or the level of maintenance necessary to rid the indoor environment of mold spores. When left unattended, mold spores can spread throughout your home making it costly to deal with them and subdue them.

Once you understand the conditions that encourage the growth and spread of mold, you can put in place mechanisms to disrupt the status quo hence eliminating or breaking into the lifecycle of the mold. There are 4 main ingredients that enhance the growth of mold and these include moisture, organic nutrients, darkness, and a surface for growth. Many HVAC systems have areas where all these four conditions occur in abundance. The key to eliminating mold is to ensure one, two, or three of these conditions are absent.

Since the best time to address the issue of mold growth in the HVAC systems is early in the manufacturing and design phase, homeowners should be on the lookout for HVAC systems that contain these anti-mold features. Manufacturers can effect relatively minor and inexpensive changes but which will have a tremendous impact on the resistance of the system to mold. Existing systems can also be modified to give the same results though such modifications may require a high level of investment.

Many homeowners believe that the mere fact they are not in hot and humid climates, they will not have to face the issue of mold. While it is true that hot and humid climates are mostly associated with mold growth, the fact of the matter is that mold can exist in any climate and in any system.

Design Measures to Curb Mold Growth

While there are many steps which can be taken to minimize or eliminate mold growth in HVAC systems, the main and effective measures include:

Positively Sloped Drain Pans

During the design process, condensate drain pans don’t receive as much attention yet they are some of the most critical components in dealing with mold. Usually, these pans are located under the cooling coils so that they can collect the moisture that condenses and drips from the coils. When the HVAC system is well designed and properly maintained, all the condensate will be collected in the pan and drained away from the system without spilling. Instead of the drain pans being slightly sloped or flat, they should be positively sloped to provide rapid draining of the condensate and prevent ponding.

Cleanable Surfaces

HVAC systems are prone to dirt accumulation and leakages. In order to minimize the impact of these vulnerabilities, you must choose a system with good materials and finishes on both the ductwork and the air handler. Instead of buying a system which has fibrous glass as the insulation on the interior of air handlers and ductwork, the insulation should be on the exterior surface, the ductwork double-walled in construction and the interior surfaces cleanable and smooth. Any installation on the interior of the system should be of closed cell construction.


Regular maintenance is central to combating the growth of mold. However, for this to happen, the HVAC components such as air handlers must be positioned in easy to access locations. This ensures a thorough cleaning and inspection hence limiting the growth of mold.

Ultra Violet Light

HVAC systems with ultra violet lighting can substantially eliminate airborne microorganisms such as mold before they are transferred to the conditioned spaces within your building. Because of the sensitive nature of UV lighting, during the design process, care must be taken to ensure the UV light system is properly installed to prevent accidental exposure of the maintenance personnel to the light. The air velocities in the system must also be low enough to permit the light to kill the microorganisms.

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