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IEC 61855:2003 — Household Hair Dryers and Styling Appliances: Performance Measurement Methods
IEC 61855:2003 defines standardized methods for measuring the key performance characteristics of household electrical hair care appliances, including hand-held hairdryers, curling irons, hairstyling wands, and hot brushes. The standard enables manufacturers, testing laboratories, and consumers to compare products on an objective and reproducible basis.
Scope Note
This standard applies to appliances for drying and styling hair intended for household and similar use. It does NOT cover radiant heating appliances, helmet-type dryers, cutting devices, or safety requirements (which are addressed by IEC 60335-2-23).
This standard applies to appliances for drying and styling hair intended for household and similar use. It does NOT cover radiant heating appliances, helmet-type dryers, cutting devices, or safety requirements (which are addressed by IEC 60335-2-23).
1. Key Performance Characteristics and Measurement Conditions
The standard identifies six primary performance characteristics that matter most to end users:
| Characteristic | Clause | Measurement Method Summary |
|---|---|---|
| Mass of the appliance | 6.1 | Weighing including supply cord; expressed in kg |
| Length of flexible cord | 6.2 | Measured from appliance inlet to plug entry |
| Power input | 6.3 | Measured at rated voltage under steady-state conditions |
| Heating-up time | 6.4 | Time to reach 95% of final steady-state temperature at nozzle outlet |
| Temperatures | 6.5 | Surface temperatures of nozzle, barrel, and handle using specified thermocouple attachment |
| Air flow (hand-held dryers) | 6.6 | Volume flow rate measured at nozzle exit using anemometer or flow bench |
| Drying rate | 6.7 | Mass of water evaporated per unit time from standardized wet test cloth |
| Drop test | 6.9 | Functional and cosmetic integrity after 1 m drop onto steel plate |
1.1 Test Room and Environmental Control
The standard mandates strict control of the test environment: temperature 20 +/- 5 C, relative humidity 50 +/- 20%, and absence of drafts. Power supply voltage must be maintained at rated voltage +/- 1%. These controls are essential for repeatability — even small variations in ambient conditions significantly affect drying rate measurements.
1.2 Thermocouple Requirements
Temperature measurements use thermocouples complying with IEC 60584-2, Class 2 or better. The standard provides detailed attachment methods, including a specialized temperature measuring device (Figure 2 of the standard, based on UL 859) that positions thermocouples at the correct distance and orientation relative to the heating element.
Measurement Pitfall
Thermocouple placement is one of the largest sources of measurement variation. The standard specifies that thermocouples for surface temperature measurement must be attached using high-temperature adhesive tape and positioned to minimize heat sinking through the thermocouple wires. Ensure the junction is in full contact with the surface over at least 10 mm of length.
Thermocouple placement is one of the largest sources of measurement variation. The standard specifies that thermocouples for surface temperature measurement must be attached using high-temperature adhesive tape and positioned to minimize heat sinking through the thermocouple wires. Ensure the junction is in full contact with the surface over at least 10 mm of length.
2. Drying Rate Measurement — The Core Performance Indicator
The drying rate test (Clause 6.7) is arguably the most important performance metric in the standard. It directly correlates with the time a user spends drying their hair.
2.1 Test Procedure
- Test Cloth Preparation: A standardized woven cotton cloth (specified in Annex B) is soaked in distilled water at 20 +/- 2 C and then wrung to a controlled residual moisture content (typically 100% dry mass increase).
- Drying Process: The test cloth is mounted on a dedicated test fixture (Figure 6 of the standard). The appliance is operated at its maximum setting and moved over the cloth in a standardized pattern.
- Measurement: The mass loss of the cloth is recorded continuously or at periodic intervals. The drying rate is expressed in grams of water evaporated per minute (g/min).
2.2 Interpretation of Results
The drying rate depends on a combination of air flow rate, air temperature, and the efficiency of heat transfer to the wet surface. A higher drying rate generally indicates superior performance, but the standard emphasizes that results are comparative rather than absolute — they are most meaningful when testing multiple appliances under identical conditions.
Engineering Insight: Drying Rate Optimization
The drying rate is a function of three variables: air velocity, air temperature, and humidity gradient at the wet surface. Increasing air temperature beyond approximately 120°C yields diminishing returns because the wet surface temperature is limited by evaporative cooling to around 40–50°C. The most effective design approach is to maximize air flow while maintaining sufficient heating. This explains why professional hairdryers typically prioritize high air flow (80–120 cfm) over extreme temperatures.
The drying rate is a function of three variables: air velocity, air temperature, and humidity gradient at the wet surface. Increasing air temperature beyond approximately 120°C yields diminishing returns because the wet surface temperature is limited by evaporative cooling to around 40–50°C. The most effective design approach is to maximize air flow while maintaining sufficient heating. This explains why professional hairdryers typically prioritize high air flow (80–120 cfm) over extreme temperatures.
3. Temperature Measurement and Safety-Related Performance
Temperature measurement is critical for both performance assessment and safety-related evaluation. The standard addresses multiple measurement points:
- Nozzle outlet air temperature: Measured using a rake of thermocouples positioned 50 mm from the nozzle exit. The heating-up time to reach 95% of steady-state temperature is recorded.
- Appliance surface temperature: Measured at the nozzle, barrel (for curling irons), and handle. Maximum surface temperatures are important for user comfort and safety.
- Curling appliance barrel temperature: For curling irons, the temperature at the center of the barrel surface is measured with the thermocouple attached as specified in Figure 5 of the standard.
Safety Note (Non-Exhaustive)
While IEC 61855 focuses on performance measurement, excessive surface temperatures or slow heating may indicate design issues that affect user safety. For comprehensive safety requirements, refer to IEC 60335-2-23. Performance testing per this standard should be complemented by safety testing per the relevant product safety standard.
While IEC 61855 focuses on performance measurement, excessive surface temperatures or slow heating may indicate design issues that affect user safety. For comprehensive safety requirements, refer to IEC 60335-2-23. Performance testing per this standard should be complemented by safety testing per the relevant product safety standard.
4. Additional Measurements and Feature Evaluation
Beyond the core performance tests, the standard covers several additional aspects:
- Airborne Acoustical Noise (Clause 7): Measured per IEC 60704-2-9 for hair care appliances. Noise levels are increasingly important for user satisfaction, particularly in household environments.
- Attachment of Accessories (Clause 6.8): Concentrator nozzles, diffusers, and styling attachments are tested for secure fit and retention during use.
- Control Settings (Clause 8.1): The availability and labeling of temperature and air flow control settings are assessed.
- Drop Test (Clause 6.9): A functional drop from 1 m onto a steel plate mounted on concrete. This simulates typical accidental drops in bathroom use.
Product Development Insight
Modern premium hair dryers increasingly incorporate ion generators, infrared heating elements, and intelligent temperature control. While IEC 61855:2003 does not specifically address these technologies, its testing framework can be adapted — the drying rate test remains the gold standard for overall performance comparison regardless of the underlying technology.
Modern premium hair dryers increasingly incorporate ion generators, infrared heating elements, and intelligent temperature control. While IEC 61855:2003 does not specifically address these technologies, its testing framework can be adapted — the drying rate test remains the gold standard for overall performance comparison regardless of the underlying technology.
Frequently Asked Questions
Q1: Can IEC 61855 be used to compare different types of hair care appliances (e.g., a hairdryer vs. a curling iron)?
The standard’s tests are designed primarily for hand-held hairdryers and styling appliances with warm air. Some tests, such as temperature measurement and heating-up time, apply to both categories. However, the drying rate test (Clause 6.7) is specifically designed for appliances that deliver heated air flow and may not be suitable for contact-based styling tools.
Q2: Why does the standard exclude radiant heating and helmet dryers?
The foreword explains that these were excluded because reliable, repeatable test methods were not available at the time of drafting. Developing such methods would have incurred considerable costs, and the market share of these appliances was relatively small. National Committees may submit proposals for future inclusion.
Q3: What is the significance of the test cloth specification in Annex B?
The test cloth specification is critical for reproducibility. Different fabric types absorb and release water differently. By specifying a particular woven cotton fabric with defined mass per unit area, thread count, and finishing treatment, the standard ensures that results from different laboratories can be meaningfully compared.
Q4: How does power input measurement relate to actual drying performance?
Higher power input generally correlates with greater heating capacity, but it does not directly determine drying rate. An efficient appliance with well-designed air flow can achieve better drying performance than a higher-power appliance with poor aerodynamics. This is why the drying rate test (rather than power alone) is the preferred performance indicator.
