ASHRAE-Standard-55 - Page 010

Extracted Content

Table 5-2 Clothing Insulation Icl Values for Typical Ensembles

Clothing Description Garments Included [ a] Icl , clo

Trousers (1) Trousers, short-sleeve shirt 0.57

(2) Trousers, long-sleeve shirt 0.61

(3) #2 plus suit jacket 0.96

(4) #2 plus suit jacket, vest, t-shirt 1.14

(5) #2 plus long-sleeve sweater, t-shirt 1.01

(6) #5 plus suit jacket, long underwear bottoms 1.30

Skirts/dresses (7) Knee-length skirt, short-sleeve shirt (sandals) 0.54

(8) Knee-length skirt, long-sleeve shirt, full slip 0.67

(9) Knee-length skirt, long-sleeve shirt, half slip, long-sleeve sweater 1.10

(10) Knee-length skirt, long-sleeve shirt, half slip, suit jacket 1.04

(11) Ankle-length skirt, long-sleeve shirt, suit jacket 1.10

Shorts (12) Walking shorts, short-sleeve shirt 0.36

Overalls/coveralls (13) Long-sleeve coveralls, t-shirt 0.72

(14) Overalls, long-sleeve shirt, t-shirt 0.89

(15) Insulated coveralls, long-sleeve thermal underwear tops and bottoms 1.37

Athletic (16) Sweat pants, long-sleeve sweatshirt 0.74

Sleepwear (17) Long-sleeve pajama tops, long pajama trousers, short 3/4 length robe (slippers, no socks) 0.96

a. All clothing ensembles, except where otherwise indicated in parentheses, include shoes, socks, and briefs or panties. All skirt/dress clothing ensembles include pantyhose and no

additional socks.

5.2.2.3 Limits of Applicability. This standard does not apply to occupants

a. Whose clothing insulation exceeds 1.5 clo b. Whose clothing is highly impermeable to moisture transport (e.g., chemical protective clothing or rain

gear) c. Who are sleeping, reclining in contact with bedding, or able to adjust blankets or bedding 5.3 Determining Satisfactory Thermal Environment in Occupied Spaces 5.3.1 Applicability. Section 5.3 is permitted to be used to determine the requirements for thermal comfort in all occupied spaces within the scope of this standard. See Sections 5.2.1.4 and 5.2.2.3 for limits to the occupants’ clothing and activity levels.

5.3.2 Methodology. The predicted mean vote (PMV) model with adjustments for solar radiation and elevated air speed is used to determine the boundaries of the comfort zone. Compliance with Section 5.3 is achieved if –0.5 < PMV < +0.5 and the requirements of Sections 5.3.5 and 5.3.6 are met. See Section 6 for full design compliance requirements.

A computer code implementation of the PMV model is provided in Normative Appendix B. The adjustment for solar radiation is described per Section 5.3.3 and Normative Appendix C. The adjustment for elevated air speed is described inSection 5.3.4 and Normative Appendix D.

Normative Appendix A through Normative Appendix D provide the full methodology to comply with this section, including computer code implementations. The Thermal Comfort Tool [ 3] includes these methods and is permitted to be used to comply with this section. Alternative calculation methods are permitted but it is the user’s responsibility to verify and document that the method used yields the same results.

Figures 5-2 and 5-3 provide graphical examples of comfort zones using the PMV model in still-air conditions. Direct use of these charts to comply with this section is allowable for the specific input conditions described on each chart. In each figure, the darker-shade comfort zone is the same, and the lighter-shade comfort zone represents a single altered input: clothing insulation (Figure 5-2) and metabolic rate (Figure 5-3).

5.3.3 Solar Radiation Adjustment. When direct-beam solar radiation falls on a representative occupant, the mean radiant temperature tr shall account for long-wave mean radiant temperature trlw and short-wave mean radiant temperature t rsw using one of the following options:

8 ANSI/ASHRAE Standard 55-2023