1. 2- INTD409 Interion Environmental Technology Fall 2014/15
University of Nizwa
Faculty of Engineering and Architecture
Dept. of Architecture & Innterior
2- INTD409 Interion Environmental Technology Fall 2014/15
W 7
Green Design Controls
Dr. Mamdouh I. Zaky

2. Green Design Controls Process Recommendations
Select experienced and innovative design team
Include performance goals in SOW
Develop quantifiable goals
Document in Owner’s Project Requirements / Basis of Design
Hire a Commissioning Agent prior to design
Use an integrated design approach
Owners, Cx Agents, all design disciplines, end-users involved in all phases of design
Energy modeling to optimize energy efficiency
Plan for preventive maintenance (PM)
Train facility operators and occupants

3. Green Design Controls Cooperative environment for decision makers
Intense effort to identify and address issues in a short time
Listen and understand needs and limitations
Envision realistic and creative solutions
Record ideas as they are introduced
Effectively express ideas in a plan to serve as a vehicle to move the process forward
Owner well-defined goals (OPR)

4. Green Design Controls Optimize daylighting to full possible extent
Building orientation, photocell controls with dimmable ballasts
Reduces lighting and cooling loads
Daylight glass and view glass are not the same
Efficient lighting design
Lighting Power Density < 1 W/ft2
Pendant direct/indirect
Occupancy sensors, auto night shut-off
Dedicated outdoor air treatment
Energy Recovery Ventilator or Demand-Controlled Ventilation
Centralize exhaust zones for energy recovery

5. Green Design Controls Efficient, tight envelope
Appropriate, well-installed insulation
Low-e, low-SHGC windows (esp. east/west facing)
Shading for south facing windows
Light colored roof
High efficiency HVAC with optimized control system
Balance with maintenance concerns
Size properly, incorporate strategies for variable loads
Energy star appliances and office equipment
Use energy modeling iteratively to identify and reduce loads, and optimize efficiency of design

6. 2- INTD409 Interion Environmental Technology Fall 2014/15
University of Nizwa
Faculty of Engineering and Architecture
Dept. of Architecture & Innterior
2- INTD409 Interion Environmental Technology Fall 2014/15
W 8
Thermal comfort zone
Dr. Mamdouh I. Zaky

7. THERMAL COMFORT

8. Why Worry About Thermal Comfort?
Designers have an ethical responsibility to cause no harm – my personal opinion
Gripes about thermal comfort are consistently the number one complaint heard by building managers/owners
Comfort decisions can have substantial energy and resource consumption implications
Comfort is the basis for a substantial investment (in a climate control system)
Green design demands (sort of ) thermal comfort

9. Two Ways to Look at Thermal Comfort
As a psychological phenomenon
As a physical phenomenon
Both views are valid, both must be tempered by statistics, and both views are important to building design efforts

10. What is Thermal Comfort?
“That condition of mind which expresses
satisfaction with the thermal environment
and is assessed
by subjective evaluation.”
ASHRAE Standard
Thermal Environmental Conditions for Human Occupancy

11. Subjective Evaluation (Asking)
1. The traditional 7-point “status” scale:
cold | cool | slightly cool | neutral | slightly warm | warm | hot
2. An alternative “action” scale:
Would you prefer: to be warmer | no change | to be cooler

12. Thermal Comfort Chart
comfort
zone(s)

13. Physical Context of Thermal Comfort
-- dishealth
-- dishealth
conditions the body’s response

14. Physical Basis of Thermal Comfort
Fundamentally, comfort involves a heat balance (a thermal equilibrium) … where:
heat in ≈ heat out
where “heat in” is provided by metabolism, radiation, conduction, convection
where “heat out” is via radiation, conduction, convection, evaporation

15. Heat Flow Mechanisms

16. Heat Flow to/from Human Body
Sensible Heat
Flows via conduction, radiation, and convection
Flow rate is generally related to space temperatures
Latent Heat
Flows via evaporation
Flow rate is generally related to space humidity
Total Heat Flow = sensible + latent flows

17. Heat Flow to/from Human Body
Conduction (sensible)
Convection (sensible)
Radiation (sensible)
Evaporation/Condensation (latent)

18. Conduction
The flow of heat between two adjacent and touching solids (or from one part to another part within an object) by direct interaction between molecules
example: walking on a beach in your bare feet
for comfort, the key environmental variable is: SURFACE TEMPERATURE

19. Convection
The flow of heat from the surface of a material to/from a surrounding fluid (usually air); the free motion of molecules of the fluid is very important in promoting heat flow example: fanning yourself with a newspaper
for comfort, the key environmental variables are: AIR TEMPERATURE | AIR SPEED

20. Radiation
The flow of heat between objects that are not in direct contact—but that can “see” each other via electromagnetic radiation; the objects may be a few inches or a million miles apart
example: warming yourself in front of a fireplace
for comfort, the key environmental variable is: SURFACE TEMPERATURE

21. Evaporation
The flow of heat that must be provided as a material changes state (from a liquid to a gas); this heat represents the energy required to break molecular bonds (called the latent heat of vaporization)
example: feeling cool coming out of a swimming pool on a breezy day
for comfort, the key environmental variables
are: RELATIVE HUMIDITY | AIR SPEED

22. Environmental Comfort Factors
Air temperature (dry bulb – deg F)
Relative humidity (%)
Air speed (ft per min)
Radiant conditions
Mean radiant temperature [MRT] in deg F
or other radiation value in Btuh per sf
These factors are controllable through design – a passive system
should control all four factors; an active (HVAC) system is expected to
control the first three (with “architecture” controlling the fourth)

23. Measuring Environmental Factors
air temperature,
RH, wind speed
air speed
data logging
surface
temperature

24. The Designer’s Job Understand the physical basis of thermal
comfort and related variables
Appreciate the influence of the psychological aspects of thermal comfort
Use this understanding and appreciation to design spaces that building users will decide are thermally comfortable

25. QUESTIONS?