A CASE STUDY OF BIG LECTURE THEATRE FEDERAL UNIVERSITY OF TECHNOLOGY AKURE WRITTEN BY OGUNRUKU O.A (ARC/05/5626) SUBMITTED TO

Transcription

1 9/1/2011 ARC 810 A STUDY ON VENTILATION REQUIREMENTS IN A STANDARD UNIVERSITY LECTURE THEATRE A CASE STUDY OF BIG LECTURE THEATRE FEDERAL UNIVERSITY OF TECHNOLOGY AKURE WRITTEN BY OGUNRUKU O.A (ARC/05/5626) SUBMITTED TO PROF OLA OGUNSOTE DEPARTMENT OF ARCHITECTURE, FEDERRAL UNIVERSITY OF TECHNOLOGY, AKURE IN PARTIAL FUFILMENT OF THE REQUIREMENT OF ARC 810 FOR THE AWARD OF M.TECH IN ARCHITECTURE

2 INTRODUCTION In the evaluation of a Lecture halls in relation to the environment in the past the past decades, the importance of providing good ventilation has become a predominating issue in the search for a model architectural environment. The issue of air flow, its sources and methods of control has been subjected to intense study. Ventilation is fundamentally important to the success of any building especially those meant for listening. With an increased awareness of the cost and environmental impacts of energy use, natural ventilation has become an increasingly attractive method for reducing energy use and cost and for providing acceptable indoor environmental quality and maintaining a healthy, comfortable, and productive indoor climate rather than the more prevailing approach of using mechanical ventilation. In favourable climates and buildings types, natural ventilation can be used as an alternative to air-conditioning plants, saving 10%-30% of total energy consumption. Modern lecture theatre design is based on the hard facts that it is a rarely new form of invention to the previous existing form. Designing a lecture theatre is a complex elaborate but constrained exercise. As with all buildings, structural needs can limit freedom and architectural style is the balance between respect for precedents and the current fashions. The lecture theatre is an example of a single performance space or a form of auditorium with a single function (speech). Due to hearing and visual complications arising from both the physiological and psychological peculiarities of individuals, it is necessary to incorporate environmental control factors like ventilation in theatre designs. In analyzing and designing a theatre, there are the additional constrains : in planning for good visual conditions and sightlines of meeting the functional demands

3 of the space in regards to layout of seating and most importantly the provision of a good ventilation conditions. In Nigeria today, it is common to find auditoriums that are hastily put together, where no consideration is given to environmental control factors like proper ventilation in design until after construction, when it is discovered that the comfort level of the building are unacceptable. This often makes it necessary for various mechanical ways of ventilation to be put in place. This is not cost effective. Therefore, it has become imperative for the architect to understand the negative impacts of insufficient ventilation planning. This report is a study of the BIG LECTURE THEATRE, located in the Federal University of Technology Akure. The study described in this report examines the building s ventilation with emphasis on the effects of building size, shape, window positions and window sizes on its general thermal comfort condition. It studies the behavior of air in spaces and the optimization of its flow to meet the specific needs of the users.

4 ANALYSIS OF VENTILATION IN CASE STUDY AUDITORIUMS (Dublin s Science Complex) University College Dublin s Science Complex opened in 1964, and was the first purpose-built academic structure to be built at the Belfield campus. The complex consists of a central lecture theatre building, which is connected by link bridge to the Biology, Chemistry and Physics buildings. The Lecture building is 8,000 m2 in size. It contains six lecture theatres, with capacities ranging from 200 to 400 occupants. Most theatres have their original heating and ventilation plant. The theatre is heated using heat recovered by the thermal wheel and a supply air heating battery. The BMS compares actual air temperature with a temperature set point and adjusts heating accordingly. The set-up could lead to an occupant experiencing cold temperatures on entering the space. To address this, temperature is maintained at 17ºC when the theatre is not occupied, but is scheduled to be occupied. UCD has three control strategies for heating and lighting regulation: (1) Occupied control - the optimum temperature of the theatre when occupied: Time schedule and occupancy detectors are in.

5 Temperature set point is 20ºC. Main lights are on, access lights are off. (2) Unoccupied control - the minimum temperature of the theatre when unoccupied: Time schedule is out (building closed).temperature setpoint is 10ºC (for fabric protection). Access lights are on, main lights are off. (3) Non-occupied control - the minimum temperature of the theatre when occupied but not scheduled for use: Time schedule is in, occupancy detector is out. Temperature set point is 17ºC.

6 VENTILATION CONDITIONS IN SELECTED BUILDING (THE BIG LECTURE THEATRE) The BIG LECTURE THEATRE is one of the lecture theatre located in the Federal University of Technology Akure campus. It is a centre designated for lecture/ speech function only. It is located in Obanla campus area and sited in between the academic buildings. It is bounded by the small lecture theatre, the ETF lecture theatre, school of engineering and engineering technology and a well landscaped environment. The major factors that affect the ventilation of this lecture theatre include its size, shape nature of materials and finishes, acoustic zoning etc. in attempting to analyse the acoustic performance of a building all these must be considered. Building size This can greatly influence ventilation condition. This is mainly because the size of the hall will have to be proportional to the number and sizes of the windows so as to allow proper exchange of indoor and outdoor air. The BIG LT (as it is popularly called) has an area of approximately 402.3sq m. With a ceiling height of 5100mm 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. Number of window openings and their sizes The big lecture theatre has 18 number window units on each side of the theatre making 36 windows servicing the whole theatre, providing both ventilation and illumination and the set of windows with different sizes. The size of opening are 24 number 1500 x 1800mm which are the

7 regular sized windows in the theatre. The rest of the windows are arranged in a ascending order AIR INLET AIR OUTLET

8 Arrangement and size of windows Discussion The openings of the lecture hall are directly opposite which adequately allows for cross ventilation in the building. The orientation of the theatre is in such a way that the adjoining buildings cannot disrupts the air flow into the building because they are at a considerable distance away from each other. The choice of window in the building provides a good ventilation compare to the number of user intended for 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.

9 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 big LT could be transformed to meet up with its present challenges, so as to create an ideal environment for learning.

10 REFERENCES Perera, E. Natural ventilation for offices. BRECSU, Building Research establishment, Watford, UK, Allard, F. Natural ventilation in buildings. James and James (Science Publishers), London, UK, Rassmussen, S. E. Experiencing Architecture. Chapter 10, Hearing Architecture. MIT Press, 1962