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Low-Resistance Air Filtration | YONGFAN
Filter Pressure Drop & Fan Energy Management

Low-Resistance Air Filtration: Particle Capture at Lowest ΔP

Low-resistance filtration is not about choosing the filter with the smallest pressure-drop number. It is about meeting the required particle-control duty while using no more fan pressure than the filtration system actually needs.

Every pascal assigned to filtration becomes part of the fan duty. In multi-stage HVAC systems, compare initial clean resistance across washable metal mesh (CJS ≤10 Pa), nylon mesh (CNL ≤15 Pa), cardboard panel (CY 24 Pa), ultra-thin (CCB 25 Pa), panel filters (CG 25–45 Pa), medium bags (ZF5–ZF9 50–120 Pa), and rigid V-banks (ZZH ≤120 Pa at 3,600 m³/h).

Lowest Clean ΔP CJS Metal Mesh (≤10 Pa Initial)
Shallow Washable CNL Nylon Mesh (10 mm / ≤15 Pa)
Medium Progression ZF5 (50 Pa) → ZF9 (120 Pa)
High Airflow ZZH V-Bank (3,600 m³/h / 295 mm)
Browse Filter ΔP Routing Pressure Budget Physics
Multi stage HVAC air filter bank testing for initial pressure drop and particle efficiency
Clean Resistance vs Dust Loading Required Cleanliness → Staged Filtration → Media Area → Loaded ΔP Budget
01 / Filtration Aerodynamics

Every Pascal Assigned to Filtration Becomes Part of Fan Duty

A filter creates resistance from the day it is installed. As dust loading increases, that resistance rises. In a multi-stage air system, the fan pressure budget must accommodate the full loaded train without sacrificing air quality.
Commercial air handling unit filter section showing differential pressure gauge and filter bank
The Total Air Path Budget

Pre-Filter + Medium + Final + Coils + Silencers + Ducts

Reducing filter pressure drop by removing a necessary filtration stage is not efficiency optimization — it compromises downstream coils and cleanroom terminal HEPA elements.

Under-Filtering to Save Pascals

Installing a coarse metal mesh where fine particle control is required shifts dust loading onto expensive coils and terminal HEPA filters, causing rapid clogging.

Result: Coil fouling & premature HEPA blinding

Ignoring Rated Airflow Velocity

A 15 Pa filter rated at 1,600 m³/h cannot be compared directly with another rated at 3,200 m³/h. Higher face velocity increases dynamic ΔP exponentially.

Result: Surging pressure drop under peak flow

Mechanical Air Bypass

A poorly sealed filter frame may appear to have low resistance because air bypasses the media. That is not energy efficiency — it is filtration failure.

Result: Zero-pressure bypass & uncleaned air

Improper Cleaning of Reusables

Inadequately cleaned washable filters retain clogged dust, tearing media and dramatically increasing resistance after reinstallation.

Result: High residual ΔP & media damage
Low-Resistance Engineering Objective
Required Particle Cleanliness at Lowest Practical Clean & Loaded ΔP for the Application

ISO 16890-2:2022 defines fractional efficiency and airflow resistance test methods. Keep resistance values attached to their rated airflow and test conditions.

02 / Filter Spectrum

Low-Resistance Primary & Medium-Stage Lineup

Compare YONGFAN’s primary washable meshes, ultra-thin panels, and medium bag/V-bank configurations across initial resistance, depth, and maintenance strategy.
Primary 01 · CJS Metal Mesh Lowest ΔP: ≤10 Pa · 45 mm Reusable

CJS Metal-Mesh Washable Primary Filter

The CJS Metal-Mesh Filter delivers the lowest published clean resistance in YONGFAN’s primary range: ≤10 Pa initial resistance at rated airflow. Constructed from multi-layer aluminum or stainless-steel mesh within a 45 mm frame, it provides robust, washable, coarse first-stage protection.

Standard models: CJS-16 (595×295×45 mm, 1,600 m³/h), CJS-22 (490×490×45 mm, 2,200 m³/h), and CJS-32 (595×595×45 mm, 3,200 m³/h). Ideal for heavy grease, moisture, and coarse industrial dust where reusability is favored.

Initial Clean ΔP
≤10 Pa (Lowest published primary ΔP)
Frame Depth
45 mm multi-layer expanded metal mesh
Airflow Rating
1,600 – 3,200 m³/h per standard cell
Maintenance Mode
100% washable and reusable construction
View Pre-Filters Request CJS Sizing
Washable multi layer aluminum metal mesh air filter showing frame and expanded mesh layers
CJS Metal-Mesh Primary Filter (≤10 Pa)
Filtration Scope:

CJS is a coarse filter. It should never replace medium filters (ZF, ZZH, ZDZ) where fine particulate retention is required downstream.

Primary 02 · Shallow & Disposable 10 mm & 25 mm · ≤15–45 Pa

CNL, CY, CCB & CG Primary Filter Routes

Matching filter depth, reusability, and disposable preferences:

  • CNL Nylon Mesh (10 mm, ≤15 Pa): Shallow washable nylon mesh; solves tight 10 mm rack constraints (CNL-16, CNL-22, CNL-32 rated 1,600–3,200 m³/h).
  • CY Cardboard Frame (25 mm, 24 Pa): Disposable 25 mm depth, G1 legacy grade, 50% gravimetric efficiency (800–3,200 m³/h).
  • CCB Ultra-Thin (10 mm, 25 Pa): Disposable 10 mm depth, G1 legacy, 40% gravimetric efficiency for ultra-compact fan-coil units.
  • CG Primary Panel (45 mm, 25–45 Pa): Broader grade flexibility (G1–G4 legacy) for general commercial HVAC air handling units.
CNL Nylon Mesh
10 mm depth · ≤15 Pa clean ΔP · Washable
CY Cardboard Panel
25 mm depth · 24 Pa · G1 Disposable
CCB Ultra-Thin
10 mm depth · 25 Pa · G1 Disposable
CG Panel Filter
45 mm depth · 25–45 Pa · G1–G4 Flexible
View Primary Filters Request Primary Quote
Cardboard panel filter and ultra thin air filters for commercial HVAC systems
CY Cardboard & CCB Ultra-Thin Primary Filters
Shallow Rack Notice:

A shallow 10 mm filter has less physical depth for media area, so dust holding capacity and replacement intervals must be accounted for.

Medium Stage · ZF Bags vs ZZH V-Bank ZF: 50–120 Pa · ZZH: ≤120 Pa @ 3,600 m³/h

Medium Filtration: Bag Progression vs Compact V-Bank Modules

Increasing filtration performance is not hydraulically free. Medium filters capture fine sub-micron particles and consume more fan static pressure:

  • ZF Bag Progression (600 mm): ZF5 (50 Pa), ZF6 (55 Pa), ZF7 (96 Pa), ZF8 (100 Pa), ZF9 (120 Pa). Extended pockets maximize media area at low clean ΔP.
  • ZZH Rigid V-Bank (295 mm): Packages large media area into a compact 295 mm depth, delivering up to 3,600 m³/h per 592/595 mm face cell at ≤120 Pa (F7 grade).
  • ZDZ Mini-Pleat (295 mm): Four efficiency/resistance balances: ZDZ-45 (≤95 Pa), ZDZ-65 (≤105 Pa), ZDZ-85 (≤120 Pa), ZDZ-95 (≤140 Pa) for oily/fume air.
ZF5 / ZF6 Bag ΔP
50 Pa (F5) / 55 Pa (F6) initial resistance
ZF7 / ZF8 / ZF9 Bag ΔP
96 Pa (F7) / 100 Pa (F8) / 120 Pa (F9)
ZZH V-Bank Airflow
Up to 3,600 m³/h per cell (≤120 Pa at F7)
Fixing Frame Matching
610×610, 508×508, 305×610 mm; 20/45/65 mm inserts
View Medium Filters View Fixing Frames
Rigid V bank medium efficiency air filter module and synthetic bag pocket filters
ZZH V-Bank (≤120 Pa) & ZF Bag Pocket Filters
Media Area Rule:

Increasing effective media area reduces media face velocity, holding resistance down while maintaining required particle separation efficiency.

03 / Filter Selection Routing

Low-Resistance Filtration Routing Table

Selection starting point for low-resistance primary and medium filtration stages across YONGFAN product families.
Selection Objective Recommended YONGFAN Family Published Clean Resistance Key Engineering Boundary Action
Lowest-resistance reusable coarse stage
 CJS Metal Mesh ≤10 Pa Coarse particulate capture only; 45 mm frame depth CJS Series
Shallow washable coarse stage
 CNL Nylon Mesh ≤15 Pa 10 mm shallow depth; washable nylon mesh CNL Series
Shallow disposable primary stage
 CY Cardboard Frame 24 Pa 25 mm cardboard frame; dry ambient air only CY Series
Ultra-thin disposable primary stage
 CCB Ultra-Thin 25 Pa 10 mm depth; documented G1 legacy grade CCB Series
Flexible-grade conventional panel
 CG Panel Filter 25–45 Pa G1–G4 legacy range; 45 mm frame depth CG Series
Lower-resistance medium bag stage
 ZF5 / ZF6 Bag Filters 50 / 55 Pa F5/F6 counting efficiency; 600 mm pocket depth clearance ZF5(6) Series
Higher medium bag stages
 ZF7 / ZF8 / ZF9 96 / 100 / 120 Pa Finer sub-micron capture; non-shedding synthetic pockets ZF7–9 Series
Compact high-airflow medium module
 ZZH V-Bank Module ≤120 Pa (at F7) 295 mm depth; up to 3,600 m³/h per full-size face cell ZZH Series
04 / Filtration Protocol

Information Required for a Low-Resistance Review

Send your air handling unit parameters and existing filter readings to optimize initial ΔP, dust holding capacity, and fan static pressure budgets.
Engineering Handoff

14 Inputs for Filter ΔP Optimization

Providing clean and dirty pressure drop limits ensures the selected filter bank delivers required indoor air quality while minimizing fan electrical draw.

1. Required Filtration Stage (Pre / Medium / HEPA)
2. Target Efficiency or Standard (ISO 16890 / EN 779)
3. Rated Airflow per Cell or Total Bank (m³/h)
4. Filter Face Size: W × H (mm)
5. Maximum Available Track Depth (295 / 600 mm)
6. Allowable Initial Clean Resistance (Pa)
7. Allowable Loaded Final Resistance Changeout (Pa)
8. Downstream Filtration Stage (e.g. Coil / HEPA)
9. Outdoor Dust Concentration & Contaminants
10. Airstream Temperature & Relative Humidity
11. Washable vs Disposable Construction Preference
12. Fan Available Static Pressure Curve Margin
13. Fan Speed Control Method (Fixed vs VFD)
14. Existing Filter Model & Measured Site ΔP
05 / Technical Q&A

Low-Resistance Filtration Frequently Asked Questions

Answers to common questions regarding lowest ΔP pre-filters, washable media lifecycle, cleanroom ΔP constraints, and changeout criteria.

Which YONGFAN pre-filter has the lowest published initial resistance?

CJS Metal Mesh at ≤10 Pa initial resistance, followed by CNL Nylon Mesh at ≤15 Pa.

Should I replace a CG panel filter with CJS to reduce resistance?

Only if CJS satisfies the required coarse-filtration duty. CG offers G1–G4 grade flexibility, whereas CJS is a reusable metal-mesh filter intended for coarse intercept only.

Is a washable filter always more sustainable?

Not automatically. Cleaning water, labor, drying time, media tear risks, and maintenance capabilities dictate lifecycle outcomes. Disposable filters are preferred where wash labor is constrained.

Does lower filter resistance always mean lower fan energy?

Lower filter ΔP reduces one static pressure component. Actual fan kWh depends on airflow, fan aerodynamic efficiency, VFD speed control, and ductwork resistance.

Why not use ZF5 instead of ZF9 to save pressure drop?

Because ZF5 (40–45%) and ZF9 (98%) perform fundamentally different filtration duties. Pressure cannot be reduced by abandoning the required particle removal level.

When should an HVAC filter be replaced?

Use measured differential pressure (ΔP) and airflow rather than arbitrary calendar intervals. Replace when final design ΔP is reached or when room air quality degrades.

Can I lower resistance by increasing the number of filters?

Yes. Increasing total filter bank face area reduces face velocity across each module, lowering initial resistance and extending dust holding life. However, AHU footprint increases.

Does low resistance matter in a cleanroom?

Yes, because multi-stage filter stacks (Pre + Medium + HEPA) consume substantial fan static head. However, terminal MPPS efficiency and ISO 14644 cleanliness take priority over ΔP.

06 / Engineering Boundaries

Optimize the Full Filtration Train, Not Just One Filter

A successful low-resistance filtration strategy preserves air quality integrity while eliminating unnecessary pressure loss across every filtration stage.
Boundary 01 / No Grade Compromise

Preserve Target Cleanliness

Never down-grade a required intermediate or final filter grade simply to achieve an attractive clean pressure drop number.

Boundary 02 / Zero Bypass

Frame Gasket Integrity

Ensure holding frame inserts (20/45/65 mm) and neoprene gaskets compress uniformly; low ΔP from air bypass is filtration failure.

Boundary 03 / Staged Protection

Coil & HEPA Life

Use properly sized medium filters (ZF7/8, ZZH) to shield expensive terminal HEPA filters from premature dust loading.

Boundary 04 / Lifecycle Monitoring

Differential ΔP Gauges

Install calibrated Magnehelic or digital ΔP transmitters across filter banks to base maintenance on measured condition.

07 / Filtration Handoff

Discuss a Low-Resistance Filtration Strategy

Optimize your air handling unit filtration train: meet target particle capture efficiency while reducing annual fan energy consumption. Send your AHU schedules to YONGFAN filtration engineers.

CJS Metal Mesh (≤10 Pa Initial) CNL Nylon Mesh (10 mm / ≤15 Pa) CG Panel Filters (G1–G4 / 25–45 Pa) ZF5–ZF9 Medium Bags (50–120 Pa) ZZH Compact V-Bank (3,600 m³/h) GCDZ Terminal HEPA / ULPA Filters
Discuss Filtration Strategy View Filter Data Sheets Contact Technical Support
Application engineers reviewing air filtration schedules and pressure drop curves
YONGFAN Air Filtration Support
Multi-stage pressure drop budgets, ISO 16890 sizing & AHU filter frame layouts.
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