THERMAL COMFORT IN DESIGN
WHAT HAPPENS WHEN WE DO NOT UNDERSTAND THERMAL COMFORT
More than 25% of occupants are dissatisfied with any given feature of their building
More than 50% of occupants are thermally dissatisfied.
Payette Office Thermal Comfort Study
Afternoon, Aug 6 - Aug 12 (2015)
Payette Office Thermal Comfort Study
Afternoon, Aug 6 - Aug 12 (2015)
PERIMETER
(Desk Spaces)
CORE
(Conference Rooms)
Andrea Love and Alejandra Menchaca (2015). Payette Office Thermal Comfort Study.
PERIMETER HEAT
If this were well insulated
PERIMETER HEAT
We wouldn’t need this
If this were well insulated
PERIMETER HEAT
We wouldn’t need this
If this were well insulated
PERIMETER HEAT
$10,000 CFD Simulation
That took 2 weeks
Found comfortable conditions with triple pane
We wouldn’t need this
If this were well insulated
PERIMETER HEAT
| Cost/ft2 Window |
Upgrade Double to Triple Pane | $5.47 |
Add Perimeter Heat to Double | $53.20 |
PERIMETER HEAT
Degrading your Window U-Value by Heating the Inner Surface
A BRIEF HISTORY OF THERMAL COMFORT MODELS
PMV Model
PMV Model
I feel hot!
PMV Model
I feel cold!
PMV Model
PMV Model
Heat generated by the body
Heat leaving the body
PMV Model
=
Heat generated by the body
Heat leaving the body
PMV Model
Model depends on 6 inputs
PMV Model
Putting PMV to the Test
Putting PMV to the Test
These researchers measured the PMV of people in thousands of real buildings and assembled the ASHRAE RP-884 database.
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Putting PMV to the Test
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Then they analyzed it!
Putting PMV to the Test
Correlation = 1
Then they analyzed it!
0 < Correlation < 1
Correlation ~ 0
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Putting PMV to the Test
Correlations (R2) between comfort votes some variables
Air Temperature of the Room
0.264
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Putting PMV to the Test
Air Temperature of the Room
0.264
PMV
0.213
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Correlations (R2) between comfort votes some variables
Putting PMV to the Test
Air Temperature of the Room
0.264
PMV
0.213
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Correlations (R2) between comfort votes some variables
Putting PMV to the Test
Air Temperature of the Room
0.264
PMV
0.213
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Correlations (R2) between comfort votes some variables
PMV is not a suitable metric to describe comfort in passive buildings.
Putting PMV to the Test
Air Temperature of the Room
0.264
PMV
0.213
Average Outdoor Air Temperature
(Naturally Ventilated Buildings Only)
0.920
de Dear, R. et al . (1997) Developing an adaptive model of thermal comfort and preference – final report on RP-884 . Macquarie University, Sydney.
Correlations (R2) between comfort votes some variables
But this is.
Putting PMV to the Test
Naturally Ventilated Building
Air Conditioned Building
Adaptive Model
Model depends on 4 inputs
Adaptive Model
How Comfort Science Exists Today
How Comfort Science Exists Today
One model for fully conditioned buildings
How Comfort Science Exists Today
One model for fully conditioned buildings
One model for fully passive buildings
How Comfort Science Exists Today
One model for fully conditioned buildings
One model for fully passive buildings
How Comfort Science Exists Today
One model for fully conditioned buildings
One model for fully passive buildings
We have no models for:
How Comfort Science Exists Today
One model for fully conditioned buildings
One model for fully passive buildings
We have no models for:
Mixed-mode (hybrid passive/AC) buildings.
How Comfort Science Exists Today
One model for fully conditioned buildings
One model for fully passive buildings
We have no models for:
Mixed-mode (hybrid passive/AC) buildings.
Transitioning between summer natural ventilation and winter heating.
How Comfort Science Exists Today
One model for fully conditioned buildings
One model for fully passive buildings
We have no models for:
Mixed-mode (hybrid passive/AC) buildings.
Transitioning between summer natural ventilation and winter heating.
Understanding how conditions of high humidity affect the adaptive model.
How Comfort Science Exists Today
This is NOT Scientifically Satisfactory
We have no models for:
Mixed-mode (hybrid passive/AC) buildings.
Transitioning between summer natural ventilation and winter heating.
Understanding conditions of high humidity in the adaptive model.
What Happens in Today’s Practice
What Happens in Today’s Practice
Everyone uses this
+
And “fakes” passive design
Almost No One Uses This
What Happens in Today’s Practice
The Consequences
The Consequences
The tropical / arid regions of the world urbanize with AC
The Consequences
The tropical / arid regions of the world urbanize with AC
Cooling electricity demands force us to burn fossil fuel
The Consequences
The tropical / arid regions of the world urbanize with AC
Cooling electricity demands force us to burn fossil fuel
Fossil fuel burning intensifies Global Warming
The Consequences
The tropical / arid regions of the world urbanize with AC
Cooling electricity demands force us to burn fossil fuel
Fossil fuel burning intensifies Global Warming
Global warming intensifies cooling demand
The Consequences
The tropical / arid regions of the world urbanize with AC
Cooling electricity demands force us to burn fossil fuel
Fossil fuel burning intensifies Global Warming
Global warming intensifies cooling demand
The Consequences
The tropical / arid regions of the world urbanize with AC
Cooling electricity demands force us to burn fossil fuel
Fossil fuel burning intensifies Global Warming
Global warming intensifies cooling demand
The Consequences
The tropical / arid regions of the world urbanize with AC
Cooling electricity demands force us to burn fossil fuel
Fossil fuel burning intensifies Global Warming
Global warming intensifies cooling demand
The Consequences
The tropical / arid regions urbanize with passive design
Cooling electricity demands force us to burn fossil fuel
Fossil fuel burning intensifies Global Warming
Global warming intensifies cooling demand
WHY OUR ENERGY MODELS HAVE HISTORICALLY NOT ENABLED THIS
Some Criticisms
Some Criticisms
This method shows WHAT the energy use is but does not help explain WHY it is this way.
vs.
This method shows WHAT the energy use is but does not help explain WHY it is this way.
Some Criticisms
This method shows WHAT the energy use is but does not help explain WHY it is this way.
Some Criticisms
This method shows WHAT the energy use is but does not help explain WHY it is this way.
This method is more ANALYTICAL rather than INSTRUMENTAL.
vs.
This method is more ANALYTICAL rather than INSTRUMENTAL.
“I know from computer modeling that humans can safely cross the sound barrier.”
“I have good daylight in my space.”
vs.
ATTEMPTING TO DISCOVER SOMETHING
SHOWING COMPLIANCE
INSTRUMENTAL
ANALYTICAL
This method is more ANALYTICAL rather than INSTRUMENTAL.
Some Criticisms
This method shows WHAT the energy use is but does not help explain WHY it is this way.
This method is more ANALYTICAL rather than INSTRUMENTAL.
Some Criticisms
This method treats the occupant as a inactive consumer of comfort instead of an active participant.
This method shows WHAT the energy use is but does not help explain WHY it is this way.
This method is more ANALYTICAL rather than INSTRUMENTAL.
vs.
This method treats the occupant as a inactive consumer instead of a participant.
vs.
This method treats the occupant as a inactive consumer instead of a participant.
vs.
This method treats the occupant as a inactive consumer instead of a participant.
Some Criticisms
This method treats the occupant as a inactive consumer of comfort instead of an active participant.
This method shows WHAT the energy use is but does not help explain WHY it is this way.
This method is more ANALYTICAL rather than INSTRUMENTAL.
Some Criticisms
This method cannot be used to evaluate fully passive buildings (it presupposes HVAC)
This method treats the occupant as a inactive consumer of comfort instead of an active participant.
This method shows WHAT the energy use is but does not help explain WHY it is this way.
This method is more ANALYTICAL rather than INSTRUMENTAL.
This method cannot be used to evaluate fully passive buildings.
This method cannot be used to evaluate fully passive buildings.
This method cannot be used to evaluate fully passive buildings.
Some Criticisms
This method cannot be used to evaluate fully passive buildings (it presupposes HVAC)
This method treats the occupant as a inactive consumer of comfort instead of an active participant.
This method shows WHAT the energy use is but does not help explain WHY it is this way.
This method is more ANALYTICAL rather than INSTRUMENTAL.
vs.
HOW THE COMFORT MAPS WORK
Effective Radiant Field
Is directly related to MRT
Air Stratification
Air Stratification
Air Flow into the Space
Heat Gain into the Space
Air Stratification
Spatial Thermal Comfort Metrics
Spatial Thermal Comfort Metrics
Spatial Thermal Comfort Metrics
LOOKING FORWARD
We wouldn’t need this
If this were well insulated
PERIMETER HEAT
| Cost/ft2 Window |
Upgrade Double to Triple Pane | $5.47 |
Add Perimeter Heat to Double | $53.20 |
TYPES OF WINTER DISCOMFORT
Radiant Discomfort
(Full-body Discomfort)
Draft Discomfort
(Ankle Discomfort)
TYPES OF WINTER DISCOMFORT
Radiant Discomfort
(Full-body Discomfort)
No more
than
10%
TYPES OF WINTER DISCOMFORT
Draft Discomfort
(Ankle Discomfort)
No more
than
20%