AHU Filter Replacement Log – Template for Ventilation & AC Systems

Why Documenting AHU Filter Replacements is Crucial

Seamless documentation of filter replacements is essential not only for operational safety but also for liability and hygiene compliance. According to standards like VDI 6022, air filters in AHUs must be regularly inspected and replaced to prevent the proliferation of microorganisms and dust contamination in supply air zones.

Precise records protect operators from legal liabilities and safeguard warranties. It also serves as proof of maintenance during official inspections or internal facility audits.

• Compliance verification for VDI 6022 and VDMA 24186
• Prevention of hygiene defects, odors, and microbial growth in the ductwork
• Energy efficiency optimization by monitoring pressure drops

Preparation, Occupational Safety, and Hygiene

Replacing air filters requires strict adherence to hygiene and safety protocols. Since used filters can contain hazardous dust, spores, and pathogens, technicians must wear appropriate personal protective equipment (PPE). The replacement process should be low-dust and performed swiftly.

• Wearing respirator masks (at least FFP2) and protective gloves for personal safety
• Switching off the AHU before opening the filter chamber to prevent dust from spreading
• Dust-tight packaging and proper disposal of old filters directly on site
• Cleaning and disinfecting the filter frame before installing new filters

Recording Filter Specifications and Differential Pressure

Technical parameters must be documented precisely for each filter stage. Modern classification follows DIN EN ISO 16890 (e.g., ePM1, ePM2.5, ePM10, or Coarse). Differential pressure is the key indicator for the optimal replacement time. Excessive pressure drop significantly increases fan energy consumption and risks filter breakthrough.

• Recording the ISO 16890 filter class and exact dimensions per filter stage
• Documenting differential pressure: recording values before and after replacement
• Comparing values with the maximum allowable final differential pressure specified by the manufacturer

Installation Check, Defect Management, and Sign-off

After the physical replacement, a thorough installation check is mandatory. A poorly fitted filter leads to bypass airflows, allowing unfiltered air to bypass the system and enter the ductwork. Any defects on seals, mounting frames, or the filter chamber must be documented immediately with action deadlines.

The report is completed with photos and the technician's digital signature, providing a tamper-proof document for your clients and internal records.