06.09.2017 - Operative Temperature / Mean Radian Temperature
Actual is dependent on environmental factors, such as , air velocity, and the uniformity of conditions, as well as personal factors such as clothing, metabolic heat, acclimatisation, state of health, expectations, and even access to food and drink.
Operative temperature (air temperature + mean radiant temperature + air velocity)
is indictaion of comes from , and air speed. It is helpful to define or predict thermal comfort for occupants of a building. Basically, is related with environmental elements, which are , air velocity, and the consolidation of conditions, also individual properties such as clothing, metabolic heat, acclimatisation, state of health. In many spaces, with low air velocity and where and may be similar, alone can be a reasonable indicator of . However, in spaces where surfaces may be heated or cooled, where there is significant , or where is present, air and may be very different and so it is necessary to take account of in assessing ...
= (ta + tr)/2
Mean Radiant temperature (sky temperature + solar radiation)
(MRT) is a measure of the average of the surfaces that surround a particular point, with which it will exchange thermal . If the point is exposed to the outside, this may include the and .
could be calculated by . This is a hollow copper sphere matt black (to give it a high ) with a sensor at its centre. .
The mean radiant temperature (MRT) is a means of expressing the influence of surface temperatures on occupant comfort. It can be calculated many ways. In its simplest and least accurate form it is a homogenous steady state area weighted average of the uncontrolled or unconditioned surface temperatures (AUST) written as
Tmr = T1A1 + T2A2 + …+ TNAN / ( A1 + A2 + …+ AN )
Tmr = mean radiant temperature, °R
TN = surface temperature of surface N, °R (calculated or measured)
AN = area of surface