In conversations with school district facilities teams, one recommendation surfaces again and again: “We should just move to a higher MERV filter.”
On paper, the logic is sound. Higher MERV ratings capture smaller particles at a higher efficiency, so cleaner classroom air should follow. But in practice (especially in districts operating 20- to 30-year-old HVAC systems) this approach often creates new challenges instead of solving existing ones.
Many facilities directors have experienced it firsthand. A district moves from MERV 8 to MERV 13 with the best of intentions, only to find that airflow suffers, temperature control becomes inconsistent, and maintenance complaints increase. What was meant to improve indoor air quality ends up straining systems already operating at their limits.
So, if the answer isn’t a higher MERV filter and you can’t replace existing HVAC infrastructure… what can you do? In many cases, your best bet is a hybrid strategy that matches HVAC filters to system capability, air purifiers in classrooms, and air quality monitoring.
The bite-sized read:
- A higher MERV filter isn’t always better. Air flow in high-MERV filters can drop by 7% and 11%, reducing ventilation rates and fresh air delivery.
- Adopting a hybrid strategy can generate nearly $60,000 in annual savings, without adding staff or replacing existing equipment.
- Using high-capacity HVAC filters, and supplementing with classroom HEPA purifiers and air quality monitoring, delivers better IAQ without operational problems.
Why the “Just Increase MERV” Approach Falls Short
HVAC filters serve two primary functions: protecting equipment and capturing larger airborne particles. Most school systems were designed around these objectives, not continuous operation at high filtration resistance.
When MERV ratings increase, so does pressure drop, the resistance air encounters as it moves through the filter. Higher MERV filters can drop air flow by 7 to 11% because they rely on denser media.
In newer systems designed for it, that resistance can be managed. In older school buildings, it often cannot. Common consequences include:
Reduced airflow to classrooms
- Hot and cold spots across campuses
- Increased fan energy use and equipment strain
- More frequent maintenance intervention
- Lower fresh air delivery
These outcomes undermine both comfort and air quality consistency
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A Smarter Approach for School Districts
Districts that see more consistent results take a step back and design filtration strategies around what their systems can realistically support.
1. Use High-Capacity Filters
Rather than pushing systems to higher MERV levels they were never designed to handle, switch to high-capacity filters that provide more filter media and longer service life without excessive pressure drop. Plus, if the system is already equipped with pressure drop monitoring, you can guide the filter changeouts by actual performance data instead of fixed schedules.
This approach helps maintain airflow, protect equipment, and reduce unnecessary maintenance while avoiding the operational issues that can result from over-restrictive filtration.
2. Address the Smallest Particles With Air Purifiers
To capture fine particles at a very high efficiency, such as viruses, bacteria, smoke, and allergens, districts deploy Alen HEPA air purifiers directly in classrooms.
Because HEPA purifiers operate independently of the HVAC system, they:
- Capture very small particles effectively
- Do not add resistance to airflow
- Reduce the particulate burden before it reaches return ducts
This allows HVAC systems to operate as designed while still delivering high-quality air.
How the Hybrid Strategy Saves You Money
For a medium-sized district (approximately 30 schools), adopting a hybrid strategy can generate nearly $60,000 in annual savings, without adding staff or replacing existing equipment. The savings come from fewer consumables, reduced labor demands, and lower risk exposure, creating measurable financial impact while maintaining operational stability.
| Category | Annual Impact |
|---|---|
| Reduced filter purchases | $16,296 |
| Reduced maintenance labor | $27,195 |
| Workers’ comp risk reduction | $10,000 |
| Insurance premium savings | $5,000 |
| Total Annual Benefit | ≈ $58,491 |
These savings recur year after year and scale proportionally for both smaller and larger districts, making the hybrid approach a durable, budget-positive operational improvement.
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Maintenance Efficiency Without Headcount Pressure or Increased Risks
By implementing a balanced filtration strategy, school districts can reduce their annual filter changes. From a safety perspective, fewer filter change events can help reduce exposure to risks associated with ladder use, rooftop access, and slips, trips, and falls. Reducing these exposures lowers the likelihood of injuries and their associated financial impact, while also supporting improvements in a district’s Experience Modification Rate (EMR) over time.
By reducing the annual change events, districts free up hundreds of labor hours that can be redirected to:
- Preventive maintenance
- Equipment performance checks
- Deferred work backlog
This improves overall facilities performance without new staffing.
What Districts See With a Balanced Filtration Strategy
When districts adopt a balanced filtration strategy, the results are both operational and occupant-focused. Rather than overloading systems, districts see more predictable HVAC performance, fewer disruptions, and steadier indoor conditions across their campuses, without triggering capital upgrades or construction projects.
Districts that use a balanced filtration strategy report:
- More stable airflow across campuses
- Fewer comfort and temperature complaints
- Reduced maintenance requests
- Improved indoor air quality consistency
- Less strain on aging HVAC equipment
- And importantly, these gains are achieved without HVAC replacement or capital construction.
Ready to improve IAQ without overloading aging HVAC systems?
Call the Alen number at 800-630-2396 or contact us here to learn how districts are achieving better air without costly replacements.
