Air filtration is one of the least exciting aspects of running a shooting range and most certainly will never add a dime to the revenue stream. However, your air filtration system does offer a great opportunity to save serious money in operational and life cycle expenses.
Whether you’re new to the shooting range business or practice continuous improvement in your range operations, ensuring the filters in your system are made for the demands of your range is always a good place to start. Most range managers would agree that all filters are not created equal. Most also know they simply can’t run down the street to the neighborhood home improvement center expecting to find filters that can withstand the air flow, pressure or particle density their shooting range requires. Routine maintenance and close monitoring of two- and three-stage systems while using the latest filter technologies is paramount to long life, fewer filter changes and reduced disposal costs.
Following is an explanation of filter types, life cycles and the new bag filter. While these are basics any range owner or manager should work with, keep in mind that every range is like a fingerprint unique to the individual, and so filter life cycles will vary because of many variables such as shooter volume, trap types, weather, humidity, the type of ventilation system and other factors.
Pre-filters: The standard process followed by many ranges is to install and change pre-filters often, whether on a calendar schedule, when experiencing a pressure drop or for some other condition-based reason. As a working basis, most range operators would agree that changing the pre-filter every five to 14 days is not uncommon.
Mid-filter: The process followed by many ranges is to change mid-filters every two to six months, whether that rotation is performed on a calendar schedule, when experiencing a pressure drop or for some other condition-based reason.
HEPA filters: The standard process followed by a majority of ranges is to change HEPA filters every six to 18 months, whether that rotation is performed on a calendar schedule, when experiencing a pressure drop or for some other condition-based reason. In our work with ranges, we do see two-stage systems where the HEPAs last only two to four months. If that’s the case with your range, it might be time to look at system improvements.
Read more on HEPA filters: Why Your Range Should be Using HEPA Filters
Bag filters: The bag filter is relatively new to the shooting range filtration industry and it has become the optimal configuration if a filter housing can accommodate the switch. Sometimes modifications are necessary, but generally pay for themselves in a short time.
These specialty filters allow a three-stage system to become a two-stage system. The bag filter replaces both the pre-filter and the mid-filter and they usually last as long as the mid-filters if the size is adequate. In addition, their disposal cost savings can be substantial, as the bags compress to a size similar to the pre-filter and one set generally needs changing every two to six months. Of course, as we said earlier, life cycles vary from range to range, so it’s best to use no less than a Merv 15 efficiency bag filter to achieve the longest life cycle from your HEPA filter.
Evaluating Your Filter System
We visit and evaluate ventilation systems in ranges every week and step inside dozens of filter housings of every shape size and configuration. We see issues in approximately 80 percent of these systems, some simple and some major. Ten minutes of instruction and proper installation techniques can save thousands of dollars a year, and having a maintenance person who cares and monitors the system closely while keeping good records can save a lot of money and keep your staff and customers safe.
A few simple improvements that will help:
- All filters should be installed in the vertical position. This includes pleats, bags, v-cells and HEPAs. Filters installed horizontally will have a shortened life and can cause premature system failure.
- Never ever allow your filters to overload to the point of blowout. Blowouts significantly shorten downstream filter life and sometimes damage mid- and HEPA filters. It’s also possible that blowouts can cause damage to fans and housings.
- Eliminate bypass in-between and around filters by securing and maintaining quality gasket seals. Poor gasket seals can skew gauge readings and quickly load up your expensive downstream filters.
- Gauge sensors and tubes should be cleaned and checked regularly. We see false readings in more than 50 percent of the ranges we visit, and often a simple cleaning is all that’s needed to remedy the situation.
Filter housings have evolved and continue to do so. A shooting range filter housing should always be engineered, designed and manufactured by a company that specializes in shooting range housings. They need to be robust in order to withstand the high airflow pressures a high-demand shooting range requires. They should also be versatile in accommodating multiple filter configurations. For example, when we’re designing housings for a range, one housing will accommodate multiple two- and three-stage filter configurations. That way the range can experiment with multiple configurations and discover the optimal filter performance for their range.
About the Author:
|About the Author: Johnny Dimicelli is range system division specialists with Airfilters, Inc., located in Houston, Texas. The company has been manufacturing air filters and filter housings for 65 years, helping range owners and managers nationwide with the latest indoor shooting range filtration technology.|