1. VENTILATION AND FENESTRATION

2. NATURAL VENTILATION
Prior to mechanical ventilation, the high ceilings of buildings created a large volume of indoor air that diluted odors and carbon dioxide
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3. NATURAL VENTILATION
Air moves through a building from higher pressure areas to lower pressure areas

4. NATURAL VENTILATION Requires:
A source of air of an acceptable temperature, moisture content and cleanliness
A force to move the air through the inhabited spaces of the building

5. NATURAL VENTILATION
Controls must be provided for the volume, velocity and direction of the airflow
Contaminated air must be cleaned and reused or exhausted from the building

6. NATURAL VENTILATION
Simplest system for getting fresh air into a building:
Outdoor air for source and wind for power

7. NATURAL VENTILATION
Wind creates local areas of high pressure – windward side of a building, and low pressure on the leeward side
Fresh air enters on the windward side and moves to the areas of lowest pressure

8. NATURAL VENTILATION Window placement is critical
Must have windows on at least 2 sides of the building, preferably opposite one another

9. NATURAL VENTILATION
Building should be designed to take advantage of prevailing winds – site orientation
Provides for a minimum of 2 – 3 air changes per hour

10. CONVECTION VENTILATION
Differences in the density of warmer and cooler air create the differences in pressure that moves the air
Uses the principle that hot air rises – the “stack” effect

11. CONVECTION VENTILATION
Warm air inside a building rises and exits near the building’s top
Cool air infiltrates at lower levels

12. CONVECTION VENTILATION

13. CONVECTION VENTILATION
Not noticeable in buildings less than 5 stories
Fire codes restrict air interaction between floors of multi-story buildings – eliminating the stack effect
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14. CONVECTION VENTILATION
Not noticeable in buildings less than 5 stories
Fire codes restrict air interaction between floors of multi-story buildings – eliminating the stack effect
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15. VENTILATION RATES Recommended Ventilation Rates for Offices:
20 cfm (cubic feet per minute) of outside air for each occupant
25% of amount is required to dilute carbon dioxide from human respiration
25% needed to counteract body odors
Remainder dilutes emissions from indoor building materials and office equipment

16. VENTILATION RATES Recommended ventilation rate for offices –
Slightly more than one air change per hour in an office with 8’ ceilings

17. VENTILATION RATES
Higher rates of air replacement are needed in buildings housing heat and odor producing activities

18. FANS
Exhaust Fans
Codes prohibit discharging exhaust fans into attics, basements or crawlspaces

19. FANS
Exhaust Fans
Solar Powered Attic Fans

20. FANS Exhaust Fans Restrooms
Must be coordinated with the ventilation system to keep odors away from other building spaces
Downstream from the airflow from other spaces
Air should be vented directly outside – not into other spaces

21. FANS Exhaust Fans Localized Exhaust Systems: Industrial process areas
Laboratories
Medical facilities
Commercial kitchens
Photocopy areas

22. INNOVATION Metal That Breathes

23. FENESTRATION fen·es·tra·tion (f n -str sh n) n.
1. The design and placement of windows in a building.

24. FENESTRATION
Fenestration of a building – windows, skylights, clerestories etc., effect heat gain and loss as well as ventilation and fenestration

25. FENESTRATION
Proportion of glass on the exterior affects energy conservation and thermal comfort
Amount of fenestration is determined by architectural considerations

26. FENESTRATION Window Orientation
North facing windows lose radiated heat in all seasons, especially winter
East facing windows gain heat rapidly in the summer
South facing windows receive solar heat in all seasons
West facing windows heat up rapidly in summer afternoons

27. FENESTRATION Windows and Natural Ventilation
The open position of a window determines how well it provides natural ventilation regarding the deflection of the wind

28. FENESTRATION Thermal Transmission is influenced by:
Window and door material
Frame materials
Glazing

29. FENESTRATION
U-Value
Expresses the heat flow through a constructed building section including air spaces of ¾” or more

30. FENESTRATION
U-Value
Developed by the National Fenestration Rating Council, a nonprofit collaboration of window manufacturers, government agencies, and building trade associations

31. FENESTRATION U-Value Measures whole window conditions
Measures how well product prevents heat from escaping a building

32. FENESTRATION U-Value General ratings – between .20 and 1.20
Smaller ratings = less heat escaping

33. FENESTRATION
Solar Heat Gain Coefficient
SHGC
Provided by the NFRC

34. FENESTRATION Solar Heat Gain Coefficient
Measures how much of the sun’s heat will pass through to the interior
Ratings 0 – 1.0
Higher rating = more heat passing through

35. FENESTRATION
Solar Heat Gain Coefficient

36. FENESTRATION Glazing Materials
Materials should be appropriate for the amount of light that needs to pass through
Thermal performance and life cycle costs are important economical considerations

37. FENESTRATION Glazing Materials
Color is important for certain applications such as artist studios, showrooms and retail spaces