Comfort standards & Requirements
Specified below are standards and guidelines, based on human judgment of thermal indoor climate and disruption caused by draught.
ANSI/ASHRAE 55(a) and DIN 1946, part 2
The American ANSI/ASHREA 55a and German DIN 1946 are often used standards. Measure instruments, procedure demands and the dimensions of the occupied zone are significant in these standards.
Comfort parameters are introduced in this standard:
PMV Predicted Mean Vote: judgment of thermal indoor climate
PPD Predicted Percentage of Dissatisfied: percentages of dissatisfied about the indoor climate
DR Draught Rating: percentage of people disrupted by draught
There is a fixed relation between the PMV and PPD value. 
When the PMV value is between the recommended –0,5 and
+ 0,5 the PPD will be lower than 10%.
The percentage
dissatisfied in this model will never be lower than 5%.
The standard recommends a maximum DR of 15%. The turbulence intensity of the air velocity has to be measured to calculate the DR. The turbulence intensity is bandwidth of the actual air velocity in relation to the measured average air velocity.
The average allowed air velocity is determined by turbulence intensity and air temperature according underneath graph. The basic assumption is that 15% of the occupants may be disrupted.
For example, with a room temperature of 25 ºC the allowed air velocity according to the graph with a turbulence intensity (ti) of 10% is 0,28 m/s, with a ti of 20% is 0,23 m/s, with a ti of 40% is 0,18 m/s and with a ti of 60% is 0,16 m/s.
Climate laboratory tests are performed according to this standard. It is essential that the accuracy and response time of the air velocity sensors comply with DIN-EN-ISO 7726.
Specific conditions for both winter season (heating) and summer season (cooling) are described in paragraph D of ISO 7730. Under these circumstances more than 80% of the occupants grade the indoor climate acceptable. Air velocity and temperature distribution in the occupied zone will be according to the standard when proper air supply diffusers are selected. Project specific HVAC installation concepts can be tested in the climate laboratory of Barcol-Air. During this test the design is checked and optimized if needed. Certainty about the thermal indoor climate is ensured up front.
This European guideline gives three quality levels for the indoor climate. Besides guidelines for thermal indoor climate, demands for air quality and acoustics are given. More narrow tolerances apply for air quality, thermal and acoustical indoor climate for the higher quality levels.
In this standard the demands for measuring instruments and procedures for the judgment of thermal indoor climate are described.
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