Ventilation at Home ECBC II, Er. Munavar Basha Submitted by Esther Kiruba 19171NB002 To help understand the percentage of Ventilation used in my home, I have tried to study and analyse the time (Hours) at which the spaces are subjected to natural and mechanical ventilation. Our house uses both Mechanical Passive Ventilation through Fans and Mechanical Active Ventilation through Air Conditioners. There of course is the Natural Ventilation by letting in the fresh air through Windows and a Patio Door. The mechanical and natural ventilation are not mutually exclusive because the use of a fan overlaps with natural ventilation and mechanical active ventilation by the Air Conditioner. To study the modes of ventilation percentage, I have divided the days as winter and summer and studied one average day each. To help in how each space is being ventilated, I have taken the Living Room, the Bedroom and the Kitchen. SUMMER Living Room ( Average Time Used 16 Hours) Air Conditioner Nil Fan 16 Hours Natural Air 16 Hours Bedroom (Average Time used 8 Hours) Air Conditioner 6 Hours Fan 8 Hours Natural Air 2 Kitchen (Average Time used 2 Hours) Air Conditioner Nil Fan Nil Natural Air 2 Hours WINTER Living Room ( Average Time Used 16 Hours) Air Conditioner Nil Fan 8 Hours Natural Air 16 Hours Bedroom (Average Time used 8 Hours) Air Conditioner Nil Fan 8 Hours Natural Air 8 Hours Kitchen (Average Time used 2 Hours) Air Conditioner Nil Fan Nil Natural Air 2 Hours
Mechanical Active Natural
Mechanical Passive
40 30 20 10 0
Living Room
Bedroom
Mechanical Active Natural
Kitchen
Mechanical Passive
30
22.5
15
7.5
0
Living Room
Bedroom
Kitchen
To help save energy, money and for a healthier atmosphere there can be various mitigation measures that should be taken. Geometry of space Good room height – at least 2.5 m and preferably 2.7 m or more Single-sided ventilation – the room depth should not exceed 2.5 times the room height, and never more than 10 m. Cross ventilation - the room depth should not exceed 5 times the room height. Stack ventilation – the distance from the facade to the roo ights should not exceed 5 times the room height.
Window opening Highly placed openings/windows in the facade - preferably 2m or more above oor level. Bottom hung inward windows or top hung outward openings in the facade. Window height, facade: Approximately 400-600 mm. A window width of approximately 1.2-1.4 m is often optimal, since often you need two window actuators if the width exceeds 1.2-1.4 m (subject to window pro le material and type, due to frame ex with single pull point). Openings evenly distributed.
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Bottom hung inward windows or top hung outward openings in the facade.
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Mitigation Measures:
Other natural ventilation guidelines Implement a night cooling or purging strategy. Preferably include thermal mass for optimum bene t of night cooling. Allow user control of ventilation via local keypad. Preference for cross ventilation, stack ventilation or hybrid ventilation in high occupancy spaces e.g. in classrooms. Preferably a minimum 7m3 per person in e.g. classrooms.
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Maximum air changes Winter: Approximately 2.5-3 h-1(average during occupied hours). Summer: Workstations: 4-6 h-1 can easily be accepted. Atriums and similar transient spaces where people stay for shorter periods: 10–15 h-1 can be accepted.