The modern HVAC market is flooded with units that brag about all kinds of bells and whistles that their manufacturers say add to the efficiency and effectiveness of the product. But there’s one aspect that’s confused many clients through the years and that’s explosion proofing. What does it mean when manufacturers say that a unit is explosion proof? Can it survive a bomb blast? Why does an HVAC unit need to be explosion proof in the first place?
The term “explosion proof” first came from The National Fire Protection Association (NFPA), when it published the word on the National Electric Code (NEC) in 1897. The NFPA defined many terms in the NEC through the years, which included hermetically sealed, intrinsically safe, purged, dust tight, and dust ignition proof.
All of these terms are actually criteria that manufacturers need to meet in making components to be installed in hazardous areas. The criteria for explosion proof demands that an HVAC unit needs to be able to withstand any explosion from within its housing. The criteria also says that an explosion proof housing needs to prevent sparks from igniting vapors, fibers, or dust in the surrounding air.
In other words, the term explosion proof doesn’t mean an HVAC unit would make an ideal bomb shelter. It means the design of the housing prevents internal sparking from causing large blasts. But it doesn’t stop there; the NEC also has something to say about operating and surrounding temperatures about explosion proof HVACs.
According to the NEC, the operating temperature of any HVAC motor shouldn’t be higher than the lowest ignition temperature of the dust and gases of the surrounding atmosphere where the unit is installed. A lot of research goes into this aspect of explosion proofing, and can take time if the manufacturer is unfamiliar with the elements present in the area.
The components of HVAC units usually have distinct nameplates on them that specify their classifications, allowing installers as well as clients to identify which component is suited for which. Still have some questions about obscure HVAC facts? Contact our team. We know all there is to know about HVACs and are more than happy to help anyone in need.
