Many HVAC professionals are familiar with the use of open filter racks. Open filter racks are often installed to allow for easy filter access by exposing an inch or so of the filter. The problem with this accessory is that it creates a large return duct leak in most systems.
This type of installation is most commonly found in basements, yet it’s also found in attics, crawlspaces, and garages. As common as this installation method is, it has some unintended consequences that can plague the safe and efficient operation of an HVAC system. Let’s look at why open filter racks can be a problem and the issues they might be creating in the systems you install, maintain, and service.