ASHRAE STANDARD 55-2004 PDF
Ashrae 55 thermal comfort-standard. Esta norma permite informarse de los estandares de confort termico y las condiciones necesarias. ANSI/ASHRAE Standard Thermal Environmental Conditions for Human Occupancy is an .. 5 December ^ Jump up to: ASHRAE Standard 55 ( ). A better way to predict comfort: the new ASHRAE standard Permalink Authors. Olesen.
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Interpretations for Standard
Clothing insulation is the resistance to sensible heat transfer provided by a clothing ensemble expressed in units of clo, which is a unit to quantify the insulation provided by garments and clothing ensembles. The standard suggests that the time of measurements should last two or more hours long, and it should also be a representative time of the year for this specific building.
In order to achieve acceptable results, the standard also suggests the minimum equipment accuracy based the current industry standard. The standard addresses the four primary environmental factors temperaturethermal radiationhumidityand air speed and two personal factors activity and clothing that affect thermal comfort. An accompanying table lists provisions for higher operative temperatures at air speeds above 0. There is a variety of means to determine the insulation provided by clothing.
The comfort zone boundaries must be adjusted to the air movements, and the zone conditions should be adjusted to avoid local thermal discomfort.
It is also specified that the methods provided by this standard are no longer valid when the clothing insulation exceed 1. As metabolic rates increase over 1.
When occupant is sitting, one has to realize the insulation effect of the chair, and the decrease of insulation due to compression of the air in the clothing. The most recent version of the standard was published in If these requirements are met and the environmental conditions inside the building fall within the indicated ranges, then compliance is achieved.
Aviation, Space, and Environmental Medicine. There is a function to determine the representative clothing insulation at each segment.
The measurement locations should be where the occupants are expected to spend time in. For such spaces, the indoor and outdoor air temperature and mean radiant temperature and the air speed need to be measured. Considering that a sleeping person or one in reclining posture will be provided with sufficient insulation with the bedding material, and he or she is also free to adjust, it is impossible to determine the clothing insulation effect for these occupants unless they are immobile.
The section sets provisions for increasing the upper air temperature limit at elevated air speeds above 0. Section 7 underwent major revisions for measuring thermal comfort in existing spaces including procedures for physical measurements and survey methods, and how to evaluate and report results.
ASHRAE 55 – Wikipedia
A occupant-controlled naturally conditioned space is where the thermal conditions of the space are primarily regulated by occupant-controlled openings. To demonstrate compliance the following must be documented, where applicable. Thermal comfort is the condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation.
When such measurement is not feasible, this standard provides four methods to determine the clothing insulation. For occupant-controlled naturally conditioned space, the adaptive model shall be used to determine the thermal comfort boundaries.
If there are multiple such locations, the measurement can be performed ashrse a representative location. Ashare third method is to add all the clo value of each garment to match the clothing ensemble in question. These values are valid for an average adult with surface skin area of 1.
For satisfaction surveys, the thermal satisfaction scale shall end with choices: The systems must be able to maintain these conditions within the expected range of indoor and outdoor operating conditions. When stqndard do not have control over the cyclical variation or drifts in indoor environmental conditions, the conditions within this section must be met.
Comfort zone refers to the combinations of air temperature, mean radiant temperature trand humidity that are predicted to be an acceptable thermal environment at particular values of air speed, metabolic rate, and clothing insulation I cl . For seating occupants, the asjrae temperature and air speed measurements shall be taken at heights stanfard 0.
Retrieved from ” https: As for point-in-time surveys, the survey should be solicited during the time of occupancy, and the satisfaction scale ought to be continuous. The standard reminds the users that they should use aahrae own judgment to match the activities being considered to the comparable activities in the table. The measured results should be evaluated against the adjusted comfort zone for the specific building.
Thus, it only provides an approximation of the clothing insulation value of a moving person.
To evaluate the probability of satisfaction from satisfaction surveys, the standard suggests dividing the number of the votes falling between “just satisfied” and “very satisfied” by the total number of votes in that questions.
Metabolic rate is the rate of transformation of chemical energy into heat and mechanical work by metabolic activities of an individual, per unit of skin surface are expressed in units of met equal to It was revised in,and If the occupant is moving, it also affects the insulation value of clothing.
These are not part xtandard the standard, but provide additional information about terms and methods described within the standard, as well as a bibliography, and a description of the addenda incorporated from the previous version in the current version.
When the number is under 20, at least 16 must reply for the survey to make the survey representative.
In the standard was updated with more extensive information on measurement protocols and an expanded definitions section. For the first, it is not correct to use the average clothing insulation value to determine the desired thermal conditions for all occupants. In standagd first form, different individuals wear different clothing due to factors that are not related to thermal conditions, and the second form is opposite.
Interpretations for Standard 55-2004
Radiant temperature asymmetry between ceiling and floor, and air and walls must be limited to reduce discomfort.
There is a figure in the section five of the standard which predicts the standadr clothing insulation of the occupants as a function of the average outdoor air temperature at