Dear Peter,

in case you use PMV index (indoor environments with HVAC system), in Annex A of ISO 7730 standard (table A5), you will find some examples of design criteria (in terms of operative temperature) for different types of space. For instance, for light metabolic rate (M=70 W/m2) in summer conditions, operative temperature ranges for class A, B and C nvironments are 24,5 +-1,0, 24,5 +-1,5, and 24,5 +-2,5 respectively (relative humidity reference value is 60%). As air temperature and relative humidity are known, it is very easy to evaluate corresponding dew point values td=td(ta, RH).

I hope this will be useful for you.

Dear Palella,

Thanks for the timely response. 

My study is focuses on outdoor environment (thermal comfort). I have relative humidity and air temperature data and I have derived the dew point temperature values (using Td = T - ((100 - RH)/5.)  proposed by M. G. Lawrence, 2005). But i have difficulty in classifying this values using sensation/comfort scales as the ones available (google search) are suited for the ''non-tropical'' climates (12.8-17.8 DegC).

Thanks.

Dear Peter,

Finding a reliable metric for the assessment of outdoor comfort conditions is a much-debated topic. In fact in literature of last 40 years you can find more and more different indices in which is very hard to trust blindly

Maybe it could be useful for you trying with the UTCI index. The computer program is available online and you will easily convert a range of UTCI values consistent with comfort conditions into dew point ranges.

If you need some help yet, please do not hesitate to contact me further.

Here below some useful references:

Your sincerely

a) F.R. d’Ambrosio Alfano, B.I. Palella, G. Riccio, Thermal environment assessment reliability using temperature–humidity indices, Industrial Health 49 (2011)95–106.

b) Moran DS, Epstein Y. (2006) Evaluation of the Environmental Stress Index (ESI) for Hot/Dry and Hot/Wet Climates. Ind Health; 44, 399-403.

c) Bröde P, Fiala D, Blazejkzyk K, Epstein Y, Holmér I, Jendritzky G, Kampmann B, Tinz B, Havenith G. (2011) Deriving the operational procedure for the Universal Thermal Index (UTCI). Int J Biometeorol; doi: 10.1007/s00484-011-0454-1. [THERE IS ALSO A SPECIAL ISSUE ON THE TOPIC]

d) http://www.utci.org/

e) Outdoor thermal sensation of pedestrians in a Mediterranean climate and a comparison with UTCI. Pantavou, K. , Theoharatos, G. , Santamouris, M. , Asimakopoulos, D. Building and Environment66, August 2013, Pages 82-95

f) Air temperature, relative humidity, climate regionalization and thermal comfort of Nigeria. Eludoyin, O.M , Adelekan, I.O, Webster, R, Eludoyin, A.O. International Journal of Climatology Volume 34, Issue 6, May 2014, Pages 2000-2018

g) A comprehensive catalogue and classification of human thermal. Climate indices. C. R. de Freitas & E. A. Grigorieva. International Journal of Biometeorology. DOI 10.1007/s00484-014-0819-3.

h) An adaptive thermal comfort model for the tropical climatic regions of India (Köppen climate type A) Mishra, A.K., Ramgopal, M. Building and Environment 85, pp. 134-143 (2015) [this could be good for indoor applications]

Thanks once again.

I thought of converting the range values of ETI to get the comfort  range of dewpoint temperature, but I felt it'd be an "academic fraud" since the effect of relative humidity and other constants vary in the two indices. I will give it a try and get back to you. 

Regards.

@Palella,

I'm so sorry for the late response. I did as you suggested and it worked. 

Thanks alot.

@Adeolouwa. Don't worry. :-)