An easily overlooked safety measure when installing rooftop units (RTUs) is the drain pan condensate overflow switch. This simple, low-cost device can save the building owner from costly water damage while helping to protect the contractor from associated drain pan overflow liability.
An Additional Layer of Protection
Under International Mechanical Code (IMC) 307.2.3, HVAC equipment that produces condensate must have either a secondary drain line or a condensate overflow switch. The reason for this precautionary requirement is easy to understand: When a rooftop unit (RTU) condensate drain becomes clogged, it may overflow and cause damage to the building.
While a second drain pan can provide an additional layer of protection, it may not be enough – without knowing there is a problem, that backup drain pan may overflow, as well. A condensate overflow switch can provide an additional, low-cost layer of protection.
P-traps
In most installations, drain pans are connected to the rooftop unit via gravity-fed “P-trap” seals
In most installations, drain pans are connected to the rooftop unit via gravity-fed “P-trap” seals. For drains that are regularly serviced and inspected, clogs are rare.
However, if P-traps are not properly maintained, they can clog, which can likewise cause the drain pan to become clogged. Once this happens, water can overflow the drain pan and lead to costly repairs.
Condensate overflow switches
Condensate overflow switches can reduce the chance of a clogged drain pan, which leads to water damage issues, by alerting the building owner or property manager through a building automation system (BAS) before an issue occurs. On Johnson Controls® Premier Rooftop Units, only the cooling operation is shut down in this type of event, the supply fan remains operational and continues to provide airflow to the space.
Condensate overflow protection is one of the many factors considered in reliable, high-performance rooftop units. To learn more about condensate overflow switches and how Johnson Controls rooftop units are engineered to provide years of dependable, high-efficiency operation.