By: Robert Martin, Associate Category Manager, Kimberly-Clark Professional Partnership Products |
Last week, we discussed the important role that a proper air filtration strategy plays in improving indoor air quality (IAQ) for improved student learning and reduced absenteeism among students and staff. But did you know that air filters also play a role in the school’s HVAC energy consumption? And that selecting air filters based upon a low initial purchase price may end up costing schools more on energy expenses in the long run if the filter does not perform well?
The good news for schools looking to improve IAQ while actively managing energy consumption and costs (not to mention greenhouse gas emissions), is that selecting the proper air filter can achieve both goals.
Energy & Air Filtration
Energy use is the largest operating cost involved in air filtration. In fact, during a filter’s useful life, HVAC fan motor energy consumption accounts for 81 percent of its total lifecycle costs. It’s all about airflow resistance: Filters with a higher resistance to airflow can cause the HVAC system motor to work harder, thus consuming more energy. Airflow resistance typically increases as filters remove more contaminants from the air. While this filtration is essential for healthier indoor air quality and protection of HVAC equipment, it can come at a cost in terms of energy consumption.
A Balanced Approach
When selecting air filters, be sure to consider the type of filtration media used to construct the filter. Filters with a good balance of mechanical efficiency and electret efficiency (via an electrostatic charge) are typically a wise choice. Filters with electret-charged media typically deliver lower airflow resistance in the same filter construction as mechanical-only filters, which translates into reduced energy costs and potentially reduced greenhouse gases.
Don’t Skimp on Filter Changes
Selecting the right filter won’t help schools save on energy costs if those filters aren’t maintained properly and changed out regularly.
Don’t be swayed by the thought that reducing the frequency of filter change-outs or downgrading to a lower-priced air filter will save money. These tactics will only backfire. Indeed, the small amount of money saved by reducing or eliminating air filter purchases or by purchasing lower-priced (and lower efficiency) filters pales in comparison to the energy and operating costs that can be saved with a robust air filter maintenance and upgrade program, as seen in the graph below.
While purchasing fewer filters may reduce initial expenses, delaying filter change-outs also causes the HVAC system to run more days at peak airflow resistance and energy usage. It doesn’t take long for peak energy usage costs to offset any savings in the filter price. Want proof? Check it out for yourself.