ASHRAE-Standard-55 - Page 022

Extracted Content

Table 6-1 Thermal Environmental Control Classification Levels

Thermal
Environmental Control
Classification Level
Control Measure(s) for Environmental
Factors Required to Achieve Level
Informative Examples Meeting Thermal
Environmental Control Classification Levels
1Each occupant is provided two or more control measures
for their personal environment.
• Private office with a ceiling fan and an occupant
adjustable thermostat
• Shared office with desktop fans and foot
warmers for each occupant
2Each occupant is provided one control measure for their
personal environment.
• Private office with an occupant adjustable
thermostat
• Shared office with a desktop fan for each
occupant
3The room or thermal zone provides multioccupant
control of at least two control measures in their shared
environment.
• Shared office with an occupant adjustable
thermostat and ceiling fan control
4The room or thermal zone provides multioccupant control
of one control measure in their shared environment.
• Shared office with an occupant adjustable
thermostat
5No occupant control of any environmental factors• Shared or private office with an unadjustable
thermostat or no thermostat

Table 6-2 Prescriptively Compliant Personal Comfort Systems

Col1Cooling
Desk fan aimed at
head/face/upper body
Capable of providing air speed at the occupant’s head/face/upper body within
range of 0.36 to 0.8 m/s (70.9 to 157.5 fpm)
Cooled chairCapable of extracting 20 W from the body
Col1Heating
FootwarmerCapable of adding 6 W to the body
Heated chairCapable of adding 14 W to the body
  1. Cooling: At design cooling condition, the measure shall change PMV by –0.5 or i. average air temperature by –3°C (–5 °F). ii. average air speed by +0.3 m/s (60 fpm). iii. mean radiant temperature by –3°C (–5 °F). iv. for personal comfort systems (PCSs), the measure shall be listed in Table 6-2 or have a minimum

corrective power of –2°C (–4°F). 2. Heating: At design heating condition, the measure shall change PMV by +0.5 or i. average air temperature by +3°C (5°F). ii. mean radiant temperature by +3°C (5°F). iii. for PCSs, the measure shall be listed in Table 6-2 or have a minimum corrective power of +2°C

(4°F). Informative Note: A single device that is capable of changing PMV in both directions ([a] and [b]) is

counted as a single control measure. For example, a thermostat that can affect the temperature in the space by –0.5 and +0.5 PMV counts as one control measure not two. 6.2 Documentation. The method and design conditions appropriate for the intended use of the building shall be selected and documented as specified in Sections 6.2.1, 6.2.2, and 6.2.3.

6.2.1 Core Documentation Requirements (applies to both Section 5.3 and Section 5.4)

a. Each unique space shall be documented. Spaces excluded from compliance documentation shall be

clearly identified as such along with the rationale for their exclusion (e.g., not regularly occupied). b. The method of design compliance shall be stated: Section 5.3 or Section 5.4. c. Each representative occupant and their location within the space shall be defined, including their cloth ing insulation ( Icl ) and metabolic rate ( met ) for each design comfort condition. Where Table 5-1 gives a

20 ANSI/ASHRAE Standard 55-2023