ARCH-432
Human Comfort
Ice Cream Social Today
3:00 to 5:00 Behind Dana and Sloan
All School Meeting
4:00 to 5:00Daggy Theater
4:00 to 5:00
Daggy Theater
Attendance
When was the first recorded example of a bioterrorist attack?
A. France (1210 AD)B. Rome (65 AD)C. Persia (600 BC)D. Egypt (1400 BC)E. Mesopotamia (5200 BC)
Attendance
C. Persia (600 BC)
During the siege of a City, a Persian King poisoned the well
serving the city with rye ergot, a common mold often found on bread.
Scientists speculate that the Salem witch trials may have been precipitated by the
same mold outbreak, whose symptoms include paranoia, hallucinations and, in
severe cases, death.
What You Need to Know
Understand the basic terms and principles of human comfortKnow what makes people comfortable and uncomfortable
What You Need To Be Able To Do
Specify comfortable conditions based upon occupancy, met level and clo valueComfort zone a building
Terms
ComfortOccupied zonePersonal parameterMet rateClo ValueMean Radiant Temperature (MRT)Temperature zoning
Comfort
“The condition of mind that expresses satisfaction with the thermal environment. A building is considered comfortable when 80% or more of the occupants will find the environment thermally acceptable”
ASHRAE Standard 55-2004
Comfort Concerns
Can be very emotionalCan be very subjectiveCan be very costly
Source: Lincoln Journal and Star
Comfort v. Productivity
Research from Texas: Building conditions can impact
student achievement by as much as 17%
Any temperature over 74° F harms student’s math and science scores
Comfort Criteria
Environment Air temperature Radiant
temperature (MRT) Building
orientation Humidity Air speed Noise Lighting
Personal Parameters Clothing (clo) Metabolism (met) Age Size
Personal Parameters – Met & Clo
Source: Bradshaw reading assignment
Heat Transfer from Occupants
How do people transfer heat to maintain comfort?
Personal Parameters
Met (Metabolic Rate) value Human reactions
to met value
Clo value Human reactions
to clo value
How do you change the environment to match the Met and the Clo?
Temperature Zones
Temperature zone = a space or group of spaces within a building with heating and/or cooling requirements sufficiently similar that comfort conditions can be maintained by a single controlling device.
Criteria for a temperature zone?
Temperature Zones
More zones more cost $?
More zones less cost$?
Clo Value
T F Increasing the Clo value in the winter is a way to save energy in the winter months in Pullman Washington. T F A Clo value corresponds to a person’s ability to gain or lose heat.
Temperature Zones
At what operating point is any HVAC system most efficient?
Team Problem Solving
Considering initial cost, comfort, activity (met level) and energy conservation, how many different temperature zones should be included on the next slide?
A. 1 to 3B. 4 to 5 C. 6 to 7D. 8+
One Answer
Zones not colored are unconditioned
4,800 CFM- 200 CFM- 150 CFM4,450 CFM
350 CFM
4,450 CFM
820 CFM
4,450 CFM-820 CFM 3,630 CFM
150 CFM-150 CFM 0 CFM
350 CFM
4,450 CFM
820 CFM 3,630 CFM+ 150 CFM+ 720 CFM4,500 CFM
What happened to the remaining 300 CFM?
Fresh Air at 720 CFM
350 CFM
4,450 CFM
820 CFM What happened
to the remaining 300 CFM?
Answer : 300 CFMBeing pulled out of instructors dressing room
Fresh Air at 720 CFM
300 CFM
350 CFM
4,450 CFM
820 CFM
Fresh Air at 720 CFM
300 CFM
- Air Neutral
4,080 CFM
350 CFM
4,450 CFM
820 CFM
Fresh Air at 920 CFM
100 CFM
+ Air Neutral
3,880 CFM
920 CFM
Mother Nature
Mother nature MUST balance Herself!
Temperature Zones
Is there a DB Temperature and RH that would provide the optimal comfort in the spaces you have identified?
Green/High-Performance Rules of Thumb
Winter Move to the left to reduce energy You can move further left if you move
up You can move further left if you
reduce velocity
Green/High Performance Rules of Thumb
Summer Move to the right to reduce energy You can move further right if you
move down You can move further right if you
increase velocity
Take-Aways (the ‘Ah-hahs’)
Comfort is a moving targetAim for 80% acceptanceFocus on the criteria you can controlKeep both eyes on ASHRAE-55Zone to optimize performance and comfort