Dust particles have high potential to catch fire and explosion. Combustible dusts can be mixture solid organic materials, many metals, and some non-metallic inorganic materials. Particles in dust and debris are normally not combustible in normal circumstances. They become combustible when they are present in right size and concentration. Dust can accumulate anywhere in the house where it can make an in route such as rafters, roofs, suspended ceilings, ducts, crevices, dust. Ignition of dust can happen in two ways, by a spark of energy, or an extremely hot surface. This is why HVAC and ducts which often get infested with debris are highly susceptible to fire.

• The filter of a HVAC prevents duct and debris from reaching the A/c or the furnace. The filters get clogged with dirt that is coming with the air stream. They need changing or cleaning every month. If not done, dust-laden filter can collapse. The dust will blow into the furnace cabinet and cause a fire.

• The air in the furnace is heated both by burner and the heat exchanger. The temperature of the heat exchanger is shot very high by the burner. The hot air goes out into the rooms though the plenum which is located above the furnace. The plenum if not cleaned regularly becomes dirty. Dust in the plenum often drops onto the top of the heat exchanger. Accumulating dirt in the heat exchanger generates a strong potential of a fire within the furnace.

• Dust accumulating on the parts of HVAC units comes mainly through the ducts. Ducts turn leaky over time through which dust and moisture sips in. As result you should get your ducts cleaned professionally from time to time to keep fire in ducts or HVAC at bay.