Alternate ventilation in hospitals


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Ventilation system in hospitals.

Published in: Self Improvement

Alternate ventilation in hospitals

  1. 1. Dr. Ajay H. Vaidya (56)Ms.Megha Bhand (7)
  2. 2.  Introduction Older system of ventilations New systems of ventilations Limitations and benefits of various ventilation methods Need of natural and mechanical ventilation system conclusion
  3. 3. People can suffer and even die as they are exposed to diseases they did not have when they come to thehospital. Often there are things, we as hospital planners and engineers could have done to prevent that germsfrom being there in the first place. These disease causing organisms enter the building on air supply ,moisture produce, breed in reservoirs installed, and move about on vehicles we maintain. Air contaminants, which includes fungus, mold, bacteria, inorganic, and organic matter, cause many problems from nuisance colds to fatal pneumonia.
  4. 4.  Poor indoor air quality.solution:- 1. The need to restrict air movement in and between the various departments.2. The specific requirements for ventilation andfiltration to dilute and remove contamination in theform of odor, air-borne microorganisms and viruses,and hazardous chemical and radioactive substances.
  5. 5. 3.The different temperature and humidity requirements for various areas; and4. The design sophistication needed to permit accurate control of environmental conditions.
  6. 6. (I) Air intake/exhaust outlet(A) Air intake:- Intakes must be located to draw in the best quality air. They must be away from vehicle exhaust, plumbing stacks, and any other contaminant source. Louvers in outside air intakes should have surface so designed to prevent entry of rainwater.
  7. 7. These intakes should be located as far as practicalbut not less than 9 m from combustion equipment stackexhaust outlets, ventilation exhaust outlets from thehospital or adjoining buildings, medical-surgical vacuumsystems, cooling towers, plumbing vent stacks, smokecontrol exhaust outlets, and areas that may collectvehicular exhaust and other noxious fumes. The bottom of outdoor air intakes serving central systems should be located as high as practical (3.6 m recommended) but not less than 1.8 m above ground level or if installed above the roof, 0.9m above the roof level.
  8. 8. These exhausts should be located aminimum of 3 m above ground level and away fromdoors, occupied areas and operable windows.Preferred location for exhaust outlets is at roof levelprojecting upward or horizontally away fromoutdoor intakes. Care must be taken in locating highly contaminatedexhausts (e.g., from engines, fume hoods, biologicalsafety cabinets, kitchen hoods, and paint booths).Prevailing winds, adjacent buildings, and dischargevelocities must be taken into account.
  9. 9. The main constituents of an AHU are Blower with drive mechanism, cooling/heating coils, condensate or drain pans and humidifier etc. As the air passes through various sections,it is susceptible to various kinds of infections.
  10. 10.  (A) Drain pan (B) Housings (C) AHU Insulation (D) heating and cooling coil
  11. 11. To prevent the flow of aircontaining infectious particulates, air filtration isprovided in Air Handling Units which filtersparticles, pathogens and water droplets carriedinto the air, either from the coils and humidifiersor through leaks in the low-pressure side of theunit. For critical care areas like operation theaters,ICU, emergency and recovery areas normallythree-stage filtration is provided.
  12. 12.  Pre-Filters (BS-6540) : These are first stage filters having efficiency 70% down to 10 Microns. These filters are cleanable and washable and installed at inlet of airstream. Fine filters (BS-6540-part-I) : Second stage filters having efficiency 99% down to 5 Microns. The pressure drop in dirty conditions should not exceed 20mm WG and the initial drop should be between 6.5 to 8.5mm WG. These filters are washable. Hepa filters: With efficiency 99.97% down to 0.3 Microns used for operating rooms and ICUs. These are special high flow types with more media to handle higher air quality (DOP tested as per federal standard 209).
  13. 13. The function of the duct is to convey the air between two points viz AHU and room to be conditioned. It also carries the room air back to the air-conditioning apparatus.Duct cleaning has been vital and comple aspect of hospital infection control.
  14. 14. In addition to the contribution by HVAC, airstream infection in a conditioned space is also addedby localfactor viz. wet walls, interior finishes,furniture, tiles, carpets, cleaning and disinfectionagents, floor tiles, granite tops, patients andattendants etc. Chemical pollutants ,odors and fungi are majorhealth hazards in indoor environment. This causesallergies and sickness of respiratory tracts. Highincidence of sickness due to allergies, asthma,fatigue, headache, cold and respiratory disorders areresults of poor indoor air quality.
  15. 15.  Keeping good Indore air quality (IAQ) Ensuring infection control. i.e. to protect the patient from becoming infected. Maintaining air temperature, relative humidity and air speed Avoid pollution Usage of natural air and light Patients rapid development and recovery
  16. 16.  Keeping good Indore air quality (IAQ) Ensuring infection control. i.e. to protect the patient from becoming infected. Maintaining air temperature, relative humidity and air speed Avoid pollution Usage of natural air and light Patients rapid development and recovery
  17. 17. Area of hospital Temp. needed in % of relative Min. % of total air 0C humidity required change of fresh air required/hourOT (need 100% 17 to 28 (adjustable) 40-45 25fresh air)Patient bedroom 24 to 28 30-40 15-25ICU 24 40-45 12-25Recovery rooms 24 to 28 30-40 15General areas 24 to 30 30-40 25
  18. 18.  Mechanical system of ventilations – Used in urban hospitals, where less space is available, no other natural alternative available. Natural system of ventilations- (not in OT and ICUs) Used in the green hospitals, where more space available , tall hospital buildings Conventional system- OR mixed ventilation ,system used in old hospitals.
  19. 19.  vacuum pipes Exhaust fans Compressors ,condensers, evaporator Automated temp. adjustment system Air distribution system Smoke detectors/exhauster High frequency alarm system in case of fire
  20. 20.  High energy consumption Maintenance Higher cost More space requirement High risk of accident due to high vacuumed pressure Technical support needed.
  21. 21.  Channel tunnel – used high pressure mechanical ventilation system. Connecting rail track between UK and France which has 50.50 km distanced.
  22. 22. A properly designed ventilation system can cleanthe air and creating clean air zones in hospitalswhile badly designed ventilation system can besource of airborne infection.
  23. 23.  Proper lay out design Divide area into zones Large windows for every room Sliding grill and duct windows Wide entrance Natural light and humidity and temperature maintained passages for keeping good (IAQ) All windows and passages angeled to ensure proper ventilation, natural light and heat control
  24. 24.  Reduce electricity consumption up to 27% Natural light /ventilation and solar energy system can save 40 lac. rupees /year in 500 bedded hospital. No technical and engineering service required. Patients recovery rate increases. Patient prefer naturally ventilated rooms . Green hospitals using natural ventilations Constant flow of natural fresh air
  25. 25.  People feels better in the good quality Indore climate Staff people work more efficiently. Patients recover more quickly Hospital must have to consider proper ventilation and natural light system during planning. New systems of ventilation needed. New technology and engineers are playing vital roles in hospitals.
  26. 26. Thank you