Clean air delivery rate, purification efficiency and cumulative purification capacity must be measured in a controlled and repeatable environment. A CADR and CCM chamber controls volume, airtightness, pollutant concentration, air mixing and sampling so that particle, formaldehyde, toluene, TVOC and other purification tests can be compared. The complete system includes the chamber, circulation, pollutant generation, sampling, filtration, cleaning and data acquisition.

1. Typical Applications

CADR indicates the effective clean-air output of an air purifier, while CCM evaluates the accumulated pollutant-removal capacity of the filter system. Test methods may be based on GB/T 18801, ANSI/AHAM AC-1 and applicable antibacterial, gaseous-pollutant or customer procedures. The pollutant type, concentration range, chamber volume and analyzer should be defined before the system is configured.

2. Main System Components

• Airtight chamber with an easy-to-clean interior and low pollutant adsorption;
• Mixing fans or circulation ducts for uniform concentration without directly blowing on the purifier;
• Particle or gas generation equipment with repeatable dosing;
• Sampling points, tubing and analyzer connections positioned to represent chamber concentration;
• Fresh-air, exhaust and filtration systems for rapid chamber cleaning after a test;
• Temperature, humidity and synchronized concentration data acquisition.

3. Chamber Volume and Material Selection

Common laboratory configurations include approximately 3 m³, 10 m³, 30 m³ and larger rooms. High-CADR purifiers require sufficient volume to avoid an excessively rapid concentration drop, while smaller chambers can improve loading efficiency for filter-development and CCM work. Interior materials, seals and tubing should be selected according to the target pollutant to minimize adsorption and outgassing.

4. Airtightness and Background Control

Leakage, wall adsorption and background concentration directly influence the result. Before testing, check the door, sampling ports, cable glands and dampers. An empty-chamber decay test should be performed to establish natural deposition and leakage. Gaseous-pollutant laboratories must verify that the chamber materials and sampling lines do not significantly absorb or release the target compound.

5. Calibration and Verification

1. Confirm effective chamber volume and sampling-point locations;
2. Calibrate temperature, humidity, particle counters, gas analyzers and flow devices;
3. Perform concentration-uniformity checks at multiple points;
4. Measure empty-chamber natural decay;
5. Verify dosing repeatability and target-concentration stabilization time;
6. Synchronize purifier start time, sampling interval and data-acquisition clock.

6. Typical Operating Procedure

Place the purifier in the defined position, close the chamber and stabilize the environmental conditions. Introduce the pollutant, mix it to a uniform concentration and record the initial value. Start the purifier at the required operating mode and sample at controlled time intervals. CADR is calculated from the concentration decay after correction for natural chamber decay. CCM testing normally uses staged pollutant loading followed by repeated performance checks under consistent conditions.

7. Common Error Sources

Typical errors include residual contamination, tubing losses, poor mixing, direct purifier airflow at the sampling point, analyzer drift, timing mismatch and excessive natural chamber decay. Each pollutant should have a documented cleaning method. Empty-chamber, background and calibration records should be retained, and multiple chambers should be periodically compared.

8. System Selection

The chamber should be selected according to purifier airflow, standard method, pollutant type and laboratory space. LSKFT can configure particle, formaldehyde, toluene, TVOC, ozone and microbiological test chambers with automated dosing, environmental control, concentration acquisition, calculation software and exhaust purification.