Assessment of relative humidity, indoor temperature and (CO2) amount with different air conditioning systems and ventilation in Northern Technical University buildings in Mosul, Iraq

Abstract

Student’s achievement is affected by indoor thermal comfort, this paper aims to compare and investigate
thermal comfort and indoor air quality (IAQ) In the classrooms to four buildings, The Northern
Technical University/ Nineveh/ Iraq that contains varies kinds of air conditioning and heating ventilation
system. Continuous on-site measurements of the internal levels of carbon dioxide (CO2), relative
humidity and temperature were registered at one-minute time intervals for each day of the week, for one
month per building, including professional and non-professional working hours as well as weekends and
comparison with ASHRAE standards. The simultaneous external temperature and the relative humidity
used in the analysis were also measured. Where the measurements were taken in the first building
(College of Technical Engineering) and the second building (Technical Institute / Community Health
Department) and the third building (University President) and the fourth building (Technical Institute) /
Department of Electricity) in (March, April, May and June) respectively. The results of the statistical
analysis for each semester showed an average hourly value the difference (p<0.05) between the different
buildings in carbon dioxide levels during the weekdays. Likewise, the difference is in hourly average
levels of significant thermal comfort parameters (p<0.05) were found between buildings such as also
throughout the week. However, the difference in average hourly temperature on weekdays for a
particular person. The three parameters during the weekend for four buildings were not large (p> 0.05).
Overflow ASHRAE carbon dioxide levels were found to be more in buildings with a fireplace and no
fan with the windows closed compared to buildings with central heating and cooling system through the
working period. Further, the thermal comfort factor was considered to be influenced by external weather
conditions and the direction of the buildings