ARCH-432

Human Comfort

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

What is ASHRAE? ASHRAE, founded in 1894, is a global society

advancing human well-being through sustainable technology for the built environment.

The Society and its members focus on building systems, energy efficiency, indoor air quality, refrigeration and sustainability within the industry.

They create the standards that all other standards are derived, LEED, Green Building Council, Codes and etc.

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?

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.

Radon Gas

Radon Gas

• Cigarette smoking is the most common cause of lung cancer. Radon is the second leading cause of lung cancer in the United States. Scientists estimate that approximately 15,000 to 22,000 lung cancer deaths per year are related to radon.

• Exposure to the combination of radon gas and cigarette smoke creates a greater risk for lung cancer than either factor alone. The majority of radon-related cancer deaths occur among smokers.

From: National Cancer Institute

Temperature Zones

At what operating point is any HVAC system most efficient?

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$?

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?

Comfort

ASHRAE Standard 55-2004Usually defined in terms of Temperature (DB) and Relative HumidityLEED Credit EQ 7.1 – Compliance with ASHRAE Standard 55-2004

Source: ASHRAE

Zones with ASHRAE Standard 55

Zones with ASHRAE Standard 55

Zones with ASHRAE Standard 55

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 of the air

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 of the air

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