Air temperature

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(No Transcript)
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Air temperature
Relative humidity
Air movement
100
- 5
Air quality (IAQ)
Surface temperatures
75 degrees
Acoustics

• Lighting
• quality
• quantity

65 degrees
Security
Building Envelop -The Third Skin
The 3rd. skin moderates the
differences between the natural environment and
the built environment

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• The combined affects of environmental conditions
  on comfort
• Air temperature
• Relative humidity
• Air movement
• Surface radiation

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The psychrometric chart Charts the combined
affects of air temperature and moisture content



Change in quantity of water in the air
Change in quantity of water in the air
Dry Bulb Temperature Reading
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Psychrometric Chart Definition of Relative
Humidity The amount of moisture in the air
expressed as a percentage of the maximum amount
of moisture the air can hold at the given
temperature. Example at dry bulb temp. of 77 and
wet bulb temp. of 63, the air is holding 50 of
its maximum capacity at 77 degrees.

Enter wet bulb reading
50 RH
Enter dry bulb reading
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Adding moisture
cooling
warming
drying
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Energy efficient zones Winter higher humidity
off-sets lower furnace thermostat
setting Summer lower humidity off-sets higher
AC thermostat setting

Adding moisture
Winter
Cool Humid
warming
cooling
Warm Dry
drying
Summer
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The saturation curve
Air is 100 saturated with moisture and
condensation begins
50 RH
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What if cooling continues ?
Air is 100 saturated with moisture and continues
to cool
50 RH
Moisture removed by condensation
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Air is 100 saturated with moisture and continues
to cool
50 RH
Moisture removed by condensation
Same air is reheated to 70 degrees and no
moisture added RH of the room goes down (dryer)
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Chart Exercises What is the RH in the
classroom? Dry bulb ________ Wet bulb
_________ RH _________



Change in quantity of water in the air
Change in quantity of water in the air
Dry Bulb Temperature Reading
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Chart Exercises Based on the current room RH, how
cool would the walls need to get to start
noticing condensation ? Dry bulb ________ Wet
bulb _________ RH _________



Change in quantity of water in the air
Change in quantity of water in the air
Dry Bulb Temperature Reading
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Chart Exercises Assume the room is at pt. A
when class begin and we are comfortable, which
direction would room condition tend to move
toward as a response to our presents ?
Mechanically (Summer) we need to (add or
remove heat) we need to (add or remove moisture)


C
B
D
A - Room starts out here
E