HOUSING AND VENTILATION (ENVIRONMENT AND HEALTH) .pptx

Ventilation is a crucial aspect of community medicine, especially in public spaces like parks. Proper ventilation helps reduce the spread of airborne diseases and ensures a healthier environment for everyone.

In the context of community medicine, ventilation involves:
1. Natural Ventilation:
Utilizing natural air movement through windows, doors, and vents to circulate fresh air.
2. Mechanical Ventilation: Using fans, exhaust systems, and HVAC units to enhance air circulation and filtration.

Park's Textbook of Preventive and Social Medicine emphasizes the importance of adequate ventilation in public health settings to prevent disease spread and promote overall well-being.
Proper ventilation helps improve indoor air quality. Ventilation can control indoor humidity and airborne contaminants, both of which either contribute to or act as health hazards.

Ventilation and Indoor Humidity
High indoor humidity can spur mold growth. High humidity may result from poor construction or rehabilitation, site design that does not properly manage water, and/or inadequate air exchange. A reasonable target for relative humidity is 30-60%. A low-cost hygrometer, available at hardware stores, can be used to measure relative humidity. In cool climates, inadequate ventilation in the winter can contribute to excessive moisture and humidity because normal activities create moisture (cooking, bathing, breathing), and there is insufficient natural ventilation (opening windows) or mechanical ventilation (fans, exhaust systems) to remove the moisture. In warmer climates, the heating, ventilation, and air conditioning (HVAC) system can pull warmer, humid air inside. In this case, the ventilation system may help create indoor humidity problems unless the system also dehumidifies the air.
Understanding and controlling building ventilation can improve the quality of the air we breathe and reduce the risk of indoor health concerns including prevent the virus that causes COVID-19 from spreading indoors.

This roadmap aims to define the key questions users should consider to assess indoor ventilation and the major steps needed to reach recommended ventilation levels or simply improve indoor air quality (IAQ) in order to reduce the risk of spread of COVID-19.

It also includes recommendations on how to assess and measure the different parameters, specifically in health care, non-residential and residential settings whenever a person is under home care or home quarantine.

1. VENTILATION ENVIRONMENT & HEALTH [COMMUNITY MEDICINE ] BY MD SANEN S BHMS 2019-BATCH AMSHMC BELGAUM

2. DEFINATION Modern concept of ventilation not only implies replacement of vitiated air by supply of fresh outdoor air, but also control of the quality of incoming air With regards to its temperature, humidity & purity With a view to provide a thermal environment that is comfortable & free from risk of infection .

3. STANDARDS OF VENTILATION Most of the standards of ventilation have been based on the efficiency of ventilation in removing body odour Cubic space Air change Floor space

4. Different workers have advocated standards for the minimal fresh air supply ranging from 300 -3,000 c.ft . per hour per person. The widely quoted standard is that of De Chaumont who advocated a fresh air supply of 3,000 c.ft . per person per hour on the following grounds.

5. It is now established that the carbon dioxide theory is not quite correct because even if the co2 content of air is raised to over 5 per cent and the 0 2 content reduced to 18 per cent, there were no deleterious effects so long as the "cooling power" of the air was satisfactory. Air change is more important than the cubic space requirement

6. floor space per person is even more important than cubic space. Heights in excess of 10 to 12 feet are ineffective from the point of view of ventilation, as the products of respiration tend to accumulate in the lower levels The optimum floor space requirements per person vary from 50 to 100 sq.ft .

7. TYPES OF VENTILATION NATURAL VENTILATION The wind The wind is an active force in ventilation. When it blows through a room, it is called perflation When there is an obstruction, it bypasses & exerts a suction action at it tail end this is called aspiration Doors & windows facing each other provide_ cross ventilation

8. Diffusion Air passes through the small openings or spaces by diffusion

9. Inequality of temperature Air flows/passes from high density to low density It rises when heated

10. 2. MECHANICAL VENTILATION Exhaust ventilation Air is extracted or exhausted to the outside by exhaust fans usually driven by electricity

11. Plenum ventilation fresh air is blown into the room by centrifugal fans so as to create a positive pressure, and displace the vitiated air.

12. Balanced ventilation combination of the exhaust and plenum systems of ventilation

13. Air conditioning "the simultaneous control of all, or at least the first three of those factors affecting both the physical and chemical conditions of the atmosphere within any confined space or room. These factors include temperature, humidity, air movement, distribution, dust, bacteria, odours and toxic gases, most of which affect in greater or lesser degree the human health and comfort"

14. References : Parks CM Textbook 1. Bedford, T ( 1964). Basic Principles of Ventilation and Heating. Lewis, London. 2. Wilkie , W. (1965), Jordan's Tropical Hygiene and Sanitation, Bailliere Tindall&Co .

15. THANK YOU!