A STUDY ON
VENTILATION REQUIREMENT IN STANDARD UNIVERSITY LECTURE THEATRE
CASE STUDY OF 750 CAPASITYLECTURE THEATRE
FEDERAL UNIVERSITY OFTECHNOLOGY AKURE.
BY
AKINMABOGUNJE ADENIYI
ARC/05/5575
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT
FOR THE AWARD OF MASTER OF TECHNOLOGY IN
ARCHITECTURE
TO
THE DEPARTMENT OF ARCHITECTURE
SCHOOL OF ENVIRONMENTAL TECHNOLOGY
FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE
COURSE LECTURER: PROFESSOR OLU OLA OGUNSOTE
SEPTEMBER 2011
ABSTRACT
Causes of the sick building syndrome are mainlylinked with the trend of making highly insulatedairtight houses, which lowers the amount of naturalventilation (Iwashita et al., 1997). Thekey index of indoor air (IA) pollution is the CO2concentration. If the indoor CO2 level is high, therisk of the sick building syndrome rises .The degree of contamination of indoor airquality can be evaluated by measuring CO2 levels.Appropriate room ventilation is necessary to maintain an appropriate environment for indoor air or to decreasethe level of toxic chemical substances.The aim of this write up is to look at ventilation requirement in standard university lecture theatre using 750 capacity lecture hall in FUTA as a case study,And finally, to exclusively propose appropriate solutions to the issue of ventilation in buildings.
INTRODUCTION
Ventilation systems heat and cool occupied spaces for thermal comfort and provide outdoor airto dilute contaminants generated by building occupants and their activities and by buildingmaterials and furnishings. The outdoor air intake rate is determined from building codes andstandards. Designing a space for teaching and learning requires careful planning and organization. It requiresclose collaboration between the architect and the engineers. A well designed space with adequate ventilation is as a result of careful coordination ofinformation gathered from architectural and engineering disciplines as well as established instructionaltechnology principles.Ventilation is the replacement of used inside air with outside air and it has three major functions, supply of fresh air body cooling and structural cooling or heating. Air movement through building can be induced by the stack effect, wind pressure or mechanical means such as fans. Evaporative coolers,air conditioners .The factor that affect air flow through buildings are external features and factors, number and size of openings. Position of opening and components. Air flow around buildings is determined by the shape, height orientation and planning of buildings ventilation is predicted by mathematical formulae or with the aid of models. Minimum ventilation standards provide for supply of fresh air forbody cooling and structuralcooling
BASIC CONCEPT IN VENTILATION
Ventilation is the replacement of used inside air by outside air. Cross ventilation is ventilation achieved by placing opening in opposite wallsof an enclosure. Natural ventilation is ventilation achieved without mechanical aids,but by stack effect and wind pressure. Comfort cooling is the use of air movement for body cooling. Air movement refers to the circulation of air within a space and is not necessarily associated with ventilation. Infiltration is un controllable air flow into or through a building especially via gaps indoors and windows. Ventilation is measured in air changes per hour;ventilation has three major functions-those of supply of fresh air body cooling and structural cooling/heating.See table below.
VENTILATION FUNCTION AND REQUIREMENTS.
Function / Fresh air / Body cooling / Structural coolingRequired / In all occupied buildings / In warm humid conditions / In hot dry conditions
Suitable building / All buildings / Single banked buildings / High internal heat capacity
Adequacy of methods
Stack effect / Adequate / Not adequate / Adequate
Wind pressure / Adequate / Good if available / Adequate
Mechanical / Not necessary / May be desirable / Not necessary
Change per hour / 1 / 100 / 10
GENERAL CHARACTERISTICS
LOCATION
The 750 capacity ETF lecture theatre located in Obanla, FUTA was commissioned by the President Olusegun Obasanjo on the 4thof December 2004. Since then it has been a major venue for lectures within the school,the building is located within the Academic core of the Obanla campus of the Federal University of Technology Akure. It is bounded on the right side by the SATBuilding, on the left by the SEET building, on the rear by the BIG lecture theatre building,and facing the road that leads to SET building
NB This is achieved taking a cue from the front Elevation.
ARCHTECTURAL DESIGN
The building is designed as a Lecture theatre with a maximum capacity of 750 persons seated. It has a rectangular geometry with the longer side parallel to the big LT. On the interior space, a podium is provided at the front of the theatre for lecture purpose. The theatre is divided into three rows by middle and two side aisles which provide for easy circulation. There is a 150mm riser demarcating each pews in the sitting area .These is done so there will not be any obstruction in the circulation of air and individual will have direct accessto ventilationfor. The space has two escape routes at the back of the seating for access for ventilation and easy evacuation of users in case of emergency.
The area of the ETF is approximately 568.7sq m. with a ceiling height of 7200mm at the lowest floor level and 3600mm at the highest floor level. It is rectangular with chamfers at the rear corners and at the stage.
THE FLOOR PLAN OF ETF LECTURE THEATRE SHOWING POSITION OF OPENINGS
Arrangements of opening
From the floor plan above it is clear that the air that comes in into the building are cross ventilated and are placed in such a way that the sitting arrangement cannot obstruct the air that comes into the building, another factor that can influenced this is the height of the building because we need to equate the capacity of the building with the height of the building so that when the place is crowded the co2 emitted can have a space to stay before it finally goes out.
ETF interior showing openings and arrangement of furniture
SITE PLAN SHOWING DIRECTION AND MOVEMENT OF AIR THAT HAS EFFECT ON THE BUILDING
THE ORIENTATION AND PLANNING OF THE BUILDI
SIDE VIEW OF THE BUILDING SHOWING ARRANGEMENT OF OPENINGS
SIZE OF OPENING
The size of opening of this building is 1200mmx3000mm and there are five of it on side elevation arranged in ascending order which make a total of 10 number of 1200mmx3000mm opening in the building and are opposite each other, but this size of opening has no significant effect on the amount of air that enters the building because of the choice of window where half of it are fixed which brings it down to 600mmx3000mm opening that air flow can pass through, this can be seen in the picture above.
FRONT VIEW SHOWING SOME OPENINGS
PICTURE SHOWING CEILING THAT COMPLEMENT THE NATURAL VENTILATION
SECTION OF ETF BUILDING SHOWING AIR FLOW THROUGH THE BUILDING
FINDINGS AND DISCUSIONS
Since ventilation is the replacement of indoor air with outdoor air, the orientation of the lecture theatre was accurate in such a way that the north east trade wind and the south west trade wind will be able to penetrate the building.
The openings of the lecture hall was directly opposite which provide a cross ventilation in the building
The height of the building is enough for air circulation within the building
The arrangement of the opening is functional in such a way that you cannot be distracted with activities going on outside the buildings
The shape of the building allows easy access of ventilation and easy outlet of the co2emitted.
The planning is in such a way that the adjoining buildings cannot disrupts the air flow into the building because they are in a considerable distance away from each other
The choice of window in the building cannot provide a good ventilation compare to the number of user if the building because half of the window are fixed which do not allow for 100% ventilation in the building.
There is a provision of electric fan to complement the natural ventilation but this is not adequate compare to the number of intending user.
RECOMMENDATION
Since ventilation can be predicted by mathematical formula or with the aid of models to provide a minimum ventilation standard, all this are things to be put into consideration before embarking on a construction of lecture theatre so as to make the place comfortable for intending users
Ventilation is ventilation achieved by placing openings in opposite wall of the enclosure, this should not be jeopardized with the choice of window, i.e. making use of 100% ventilated window.
Natural ventilation should be the priority in designing any lecture hall in this part of the country because of the epileptic supply of electricity which will allow for mechanical aid.
The form of the spaces should generally suit the function. There should be minimal fenestrationto walls near or at the front of the theatre so as not to detract from the main focal point i.e.Lecturer and boards and screens.
CONCLUSION
The treatment of ventilation is an important issue to be considered in an interior space of every building. From preliminary design to detailed design stage, ventilation should be considered while planning the building layout. Idiosyncrasy of the area as pertaining to ventilation should also be put into consideration. The facilities in the building should also be maintained and replaced when needed to curb the present challenge in the LT. This report has clearly stated the present situation at the 750 capacity lecture theatre could be transformed to meet up with its present challenges, so as to create an ideal environment for learning.
REFERENCES
Clements-Croome DJ, Awbi HB, Bakó-Biró Zs, KochharN, Williams M.(2008). Ventilation rates in schools. Building andEnvironment;43:362–367.
Griffiths M, Eftekhari M.(2008). Control of CO2 in a naturallyventilated classroom. Energy and Buildings. 40:556–560
Iwashita G, Sakamoto M, Akasaka H. (1997).Pilot study on theoccupancy condition and the time fluctuation of ventilationrate and indoor air pollution in the housing complexduring summer season.
Ogunsote O. O. (1993). An Introduction to building climatology. A Basic course for Architecture students. Ahmadu Bello University Press, Zaria.
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