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January_LifecycleCosts

Want to Know How Much Your Air Filters Really Cost?

By: Robert Martin, CAFS, Associate Category Manager, Kimberly-Clark Professional Filtration  |   02.05.16

If you think you’re done paying for your air filters when you pay the invoice, you’re mistaken. An air filter’s purchase and maintenance price is just a small part — 18 percent — of the overall cost to operate the filter. To determine the true lifecycle cost of your air filters, you need to consider the related energy costs involved. 

What is the primary factor that determines the lifecycle cost of a filter? Energy consumption. In fact, the energy used to operate an air filtration system accounts for about 81 percent of the annual cost.

The cost-savings stream associated with energy can be estimated by examining the impact of a filter’s airflow resistance. With a lower airflow resistance, the HVAC system needs to overcome less resistance to deliver the required airflow, thus reducing the system’s energy consumption. 

Unlike filters made with media that uses on mechanical methods of particle capture, filters made with media that also incorporates an electret charge typically have less resistance to airflow, thus reducing electricity costs in use while maintaining high particle capture efficiencies. 

The chart below illustrates the potential annual savings in energy costs when using a filter with electret-treated media (Filter A). Note the difference in initial airflow resistance between the electret-treated media filter and the filter (B) using mechanical filtration methods only. While a savings of $83 may not seem significant, keep in mind that those savings are per filter.

 

Filter A

Filter B

Efficiency

MERV 14

MERV 14

Filter Style

12” Deep Rigid

12” Deep Rigid

Initial Airflow Resistance

0.27 in. WG

0.60 in. WG

Final Airflow Resistance

1.40 in WG

1.50 in WG

Energy Cost

$301/year

$384/yr

Energy consumption modeled using the calculation: Energy Consumption = Q*dP*t/n*1000 Assumes 24/7/365 operation, energy cost of $0.1033/kWh, fan, motor, drive efficiency (n) of 58%, Filter A airflow rated at 0.93  cubic meters/second, Filter B airflow rated at 0.94 cubic meters/second

 

Don’t Delay Filter Changes

Facility managers and maintenance personnel also may be tempted to delay filter change-outs in an attempt to save money. However, the small amount of money saved by reducing air filter purchases pales in comparison to the energy and operating costs consumed due to increased airflow resistance from dirty filters. It doesn’t take long for peak HVAC energy use to offset any savings in filter purchases. Instead, follow the recommendations of the filter manufacturer to determine the proper frequency for changing filters. 

Air Filtration Costs Are Everybody’s Business

It’s important for everyone involved in facility management and maintenance to understand the nuances of air filtration costs. In many cases, one department (and budget) may be responsible for purchasing air filters and filter service contracts while another is responsible for energy expenditures. 

The problem inherent in this system is that the filter purchaser can easily and innocently make a costly decision for the enterprise by choosing to purchase filters without considering their energy consumption implications, or worse, their impact on air quality and tenant satisfaction. 

The air filtration industry is extremely competitive with many products perceived as non-differentiated and substitutable. Because the initial purchase price of a filter is tangible, one can see the cost savings and resultant effect on budget immediately. This is the same reason coupons work so effectively in the consumer retail market; they provide instant satisfaction. 

It is imperative for decision-makers to look beyond the line item purchase price of filters when seeking to reduce their overall cost. A good understanding of the various costs involved over the lifecycle of an air filter is the first step toward getting more for your money.

 

 

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A further suggestion is that attention be paid to documenting the amount of ventilation air actually delivered to the building occupants, as VAV boxes serving conference rooms are typically causing ventilation deficiencies.
By: David Bearg