1. Standard Name and Summary‌

‌ Standard Name‌: F3628-24
‌ Test Method‌: This standard specifies the measurement of cooling energy released to the wearer’s skin through moisture transport and evaporation in clothing materials under controlled environmental conditions, utilizing a sweating hot plate. It establishes procedures for quantifying cooling energy during simulated "sweating" and drying phases and provides methods to calculate drying time and evaluate the efficiency of clothing materials in aiding liquid water evaporation.

‌‌

2. Scope‌

1.‌Applicability‌:
 Covers the measurement of cooling energy released by clothing materials via moisture movement and evaporation under controlled conditions.  Excludes attributes such as air permeability, thermal insulation, and evaporative resistance.
2.‌Units‌: SI units are the standard.
3.‌Safety‌: Users must establish appropriate safety practices and regulatory compliance.

‌‌

3. Referenced Documents‌

 ASTM F1494: Terminology for Protective Clothing.
 ASTM F1868: Test Method for Thermal and Evaporative Resistance of Clothing Materials Using a Sweating Hot Plate.

‌‌

4. Terminology‌

 Definitions of terms related to protective clothing are provided in ASTM F1494.

‌‌

5. Significance and Application‌

1.‌Moisture Management‌:
 Critical for maximizing cooling and comfort during physical activity by facilitating sweat evaporation.
 Cooling energy values determine the suitability of materials for specific applications.
2.‌Environmental Influence‌:
 Environmental conditions significantly affect cooling energy. Caution is required when extrapolating results beyond tested conditions.

‌‌

6. Apparatus and Equipment‌

Recommended device: EYTEST LIMITED Model E3628
1.‌Sweating Hot Plate‌:
 Test plate with heated guard section and cooling plate beneath.
2.‌Water Delivery System‌:
 Supplies uniform water flow to nine sweating pores on the test plate.
3.‌Temperature Control‌:
 Independent control for test plate, guard section, and cooling plate. 4.‌Heat Flux Measurement‌:
 Measures average heat flux loss/gain during testing.
5.‌Temperature Sensors‌:
 Thermistors, thermocouples, RTDs, or equivalents.
6.‌Environmental Chamber‌:
 Maintains selected temperature and humidity (compatible with E3628).
7.‌Environmental Monitoring‌:
 Measures air temperature, relative humidity, and airflow velocity.

‌‌

7. Materials and Specimens‌

1.‌Water‌: Use distilled, deionized, or reverse osmosis-treated water.
2.‌Specimen Preparation‌:
 Test three specimens per sample unit; remove wrinkles.
3.‌Conditioning‌:
 Equilibrate specimens in the test chamber for ≥4 hours.

‌‌

8. Procedure‌

1.‌Test Setup‌:
 Stabilize plate temperatures, water supply, and isothermal conditions.
2.‌Testing Phases‌:
 Initialization‌: Measure heat flux for 10 minutes.
 Sweating Phase‌: Activate water delivery and measure heat flux for 30 minutes.
 Drying Phase‌: Cease water supply and monitor until fabric dries.
3.‌Calculations‌:
 Total energy during sweating/drying phases, drying time, cooling efficiency, and cooling potential.

‌‌

9. Reporting Requirements‌

Include:
 Specimen details (weight, thickness, composition, construction).
 Test sequence, orientation, and environmental conditions.
 Wrinkle removal techniques, constraints/stretching methods.
 Individual and averaged results, deviations from standard protocol.

‌‌

10. Precision and Bias‌

No interlaboratory testing has been conducted.
 Current precision claims are based on proprietary data from Yunnan Yili Instrument Co., Ltd., whose device achieves industry-leading accuracy.

‌‌

11. Keywords‌

 Cooling, thermal insulation, moisture management, breathability index, thermal resistance, total heat loss, wicking.
 This standardized method enables objective evaluation of clothing materials’ cooling performance, supporting innovation in sportswear, protective gear, and thermal comfort applications.