With our Heavy Duty HEPA Vac, it is very capable of capturing particles that are very small. You do not have to worry about re-entraining the dirt that you vacuumed back into the air. The filtration efficiency of the HEPA filter is 99.97% at 0.3 micron. Because it is so efficient, we place a prefilter on the outside of the element. This helps to capture the larger particles so that they do not prematurely plug the HEPA media. In extreme conditions with large amounts of debris, we do have another option. It is the model 901373 filter protector. It is a bag that will go on the outside of the prefilter and the HEPA filter. With a large influx of contamination, the filter protector will create a matrix from the contamination to create a cake. This cake, as it builds, will start to capture smaller particles and become more efficient. It is similar to a natural dam after a big rain. The large boulders and logs collect into a section, and then the smaller rocks and branches will collect behind it.
Under normal conditions, the standard HEPA filter with prefilter will last you for a while before replacing. It is dependent on the amount of dirt that is being collected. But, in those extreme conditions, you do not want to change the HEPA filter every week. This would be too expensive. That is why EXAIR found a cost-effective option to help, the filter protector. The model 901373 filter protector can be changed in a matter of minutes and the cost is less than 2% of the HEPA filter. Just like disposable shoe covers, they are inexpensive and they protect your expensive shoes. If you require any more information on our Heavy Duty HEPA Vac or the accessories, you can contact one of our helpful Application Engineers at EXAIR.