1. Buildings: Energy, Environment and Health
EFS 2015 / 2016
Buildings: Energy, Environment and Health
Manuel C. Gameiro da Silva
Reseach Group in Energy, Environment and Comfort
ADAI-LAETA, Department of Mechanical Engineering
University of Coimbra 1

2. Energy Framework for Europe

3. Energy Framework for Europe

4. Energy Framework for Europe

5. Energy Framework for Europe
Total Energy Demand (Mtoe & %) for the countries of EU-27 (2006)

6. Buildings in Europe
Energy Demand in Services (Mtoe & %) for the countries of EU-27(2006)

7. Buildings in Europe
Energy Demand in Households (Mtoe & %) for the countries of EU-27(2006)

8. Buildings in Europe
47 m2/person
81 m2/person
26 m2/person
The size of building stock in Europe (adapted from M. Economidou et al (2011))

9. Buildings in Europe
Breakdown of European building stock (adapted from M. Economidou et al (2011))

10. Climate Zones
ECOFYS Climate zones suitable for ranking of technology options and comparison of building performance

11. Heating and Cooling Days
The best indicators to synthesize in a quantified way the greater or lesser harshness of weather conditions, respectively in situations of cold and heat, are heating degree days (HDD) and cooling degree days (CDD)
Are defined as the annual sum of daily differences between the mean outside temperature of the day and a reference temperature at which it would be not necessary to use systems either heating or cooling to maintain comfort conditions inside a building.
Normally, reference temperatures are not the same for HDD and CDD

12. Heating and Cooling Days
Heating and Cooling degrees-days for the European countries (Tref = 17ºC)
Source: Heating and Cooling Degree Days, Kevin Baumert and Mindy Selman, World Resources Institute, 2003

13. Total Energy Demand vs HDD+CDD

14. Total Energy Demand vs HDD+CDD

15. Energy Intensity of EU
Energy Intensity of the Economies of the EU-27 countries (2006)

16. Climate Zones (USA) IECC Climate Zone Miami 1A Houston 2A Phoenix 2B
IECC Climate Zone
Miami 1A
Houston 2A
Phoenix 2B
Atlanta 3A
Los Angeles 3B
Las Vegas
San Francisco 3C
Baltimore 4A
Albuquerque 4B
Seattle 4C
Chicago 5A
Boulder 5B
Minneapolis 6A
Helena 6B
Duluth 7
Fairbanks 8

17. Energy Demand (USA)
Retail Buildings (kWh/(m2.year)

18. Energy Fluxes in a Building

19. NZEB concept
Directive 2010/31/EU (EPBD recast) defines NZEB as a building that has a very high energy performance The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources The energy performance of a building shall be expressed in a transparent manner and shall include an energy performance indicator and a numeric indicator of primary energy use, based on primary energy factors per energy carrier

20. NZEB Concept

21. NZEB Concept

22. System Boundaries of a NZEB
Definition of the system boundary for the case of on-site renewable production. Adapted from Rehva (2013)

23. System Boundaries of a NZEB
Definition of the system boundary for the case of on-site renewable production. Adapted from Rehva (2013)

24. Cost-Optimal Concept
Cost-Optimal Concept

25. The Path to NZEBs

26. 1.º Changing/Reducing traditional requirements
The Path to NZEBs
1.º Changing/Reducing traditional requirements
2.º Energy Efficiency
3.º Renewables
4.º Energy monitoring

27. Domestic Hot Water (DHW) Example.
Existing DHW system serving showers in a gymnasium, using a gas boiler to produce DHW

28. Domestic Hot Water (DHW) Example.
Energy Efficiency
Changing requirements
Renewables

29. Relevant Parameters Outdoor Conditions:
Weather, Air Quality, Noise, Sunshine, Lighting, …
Environmental Impacts
Façade Characterization:
Pressure Fields, Noise Field, Light Distribution, Thermal Losses
Local Production
Thermal Losses
and/or Gains
Energy
Supply
Indoor Environmental Quality (IEQ):
Thermal, Noise, Air Quality, Light
(Physical/ Sensorial)
Sent Energy
Internal
Gains
Thermal Inertia

30. Heat Balance of the Human Body
Thermal Comfort Requirements
Heat Balance of the Human Body
Metabolic Heat
Production (M)
Wet and Dry Heat Exchanges in Respiration (Res)
External Mechanical Work (W) o
o o
Evaporation Losses in Sweating and Perspiration (E)
Radiation Exchanges with Surroundings (R)
Convection Exchanges with air Layers (C)
Conduction to or from clothing (K)
S = M - W + R + C + K - E + Res

31. Human Body Thermal Regulation
Thermal Comfort Requirements
Human Body Thermal Regulation
ENVIRONMENT
Temperature
Air Velocity
Mean Rad Temp
Rel Humidity.
SKIN
HUMAN BODY
TISSUES
Central Nervous System
Hipotalamus
Breathing
CLOTHING
Conduction
Skin Heat Flux
Deep Body temperature
Convection
Evaporation
Radiation
Blood Flux
Sweating
Shievering

32. Thermal Environment Indices
Air Temperature (ºC)
22.3
Air Velocity (m/s) ?
0.47
Equivalent Temperature (ºC))
1 clo
Radiant Temperature (ºC)
17.1
Relative Humidity (%)
65.4

33. Thermal Environment Indices
Operative Temperatura (to)
Uniform temperature of a black imaginary enclosure where the occupant exchanges the same amount of heat, by convection and radiation, as in the real one.
Equivalent Temperature (te)
Uniform temperature of an imaginary enclosure , with null air velocity, where the occupant exchanges the same amount of sensible heat as in the real one.
Efective Temperature (ET*)
Uniform temperature of an imaginary enclosure with a 50% relative humidity, where the occupant exchanges the same amount of heat aby radiation, convection and evaporation as in the real one

34. PMV = (0,303e-0,036*M + 0,028)*[(M-W) - H - Ec - Cres – Eres ]
Fanger’s Model (PMV and PPD, ISO 7730:2005 )
PMV = (0,303e-0,036*M + 0,028)*[(M-W) - H - Ec - Cres – Eres ]
+3 Hot
+2 Warm
+1 Slightly Warm
0 Neutral - +3 +2 +1
1 Slightly Cool
2 Cool
3 Cold

35. Fanger’s Model (PMV and PPD, ISO 7730:2005 )
PMV = (0,303e-0,036*M + 0,028)*[(M-W) - H - Ec - Cres – Eres ]
PMV = (0,303e-2,100*M + 0,028)*[(M-W)
- 3,96*10-8*fcl*[(tcl+273)4 - (tr+273) 4] - fcl*hc*(tcl-ta)
- 3,05*10-3*[5733 – 6,99*(M-W)-pa] -0,42*[(M-W)-58,15]
- 0,0014*M*(34 - ta) – 1,7*10-5*M*(5867-pa)]
Human vote model
Heat Generation
H1: Radiation
H2: Convection
Ec1: Perspiration
Ec2: Sweating
Breathing (sensible)
Breathing (latent)

36. Calculation Tool (PMV and PPD, ISO 7730:2005 )

37. Breakdown of human body energy losses (PMV and PPD, ISO 7730:2005 )

38. PPD Index (Predicted Percentage of Dissatisfied)
PMV-index (Predicted Mean Vote) predicts the subjective ratings of the environment in a group of people.
PPD-index predicts the number of dissatisfied people.

39. Metabolic Heat Production
1 Met = W/m2
S = M - W + R + C + K - E + Res

40. Insulation of Clothing
m2ºC/W
Jacket
0.35
0.054
Coat
0.70
0.109
Trousers
0.25
0.039
Skirt
0.18
0.028
Short skirt
0.10
0.016
Shirt
Light shoes
0.02
0.003
Boots

41. Insulation of Clothing

42. Thermal Comfort of the Human Body as a Whole – ISO 7730:2005

43. Thermal Comfort of the Human Body as a Whole – ISO 7730:2005
Discomfortable
Category C
Category B
Category A

44. Diferent ventilation strategies
Yearly distribution of comfort categories for a classroom - occupation period
Diferent ventilation strategies

45. Adaptive Models

46. Adaptive Models
Acceptability ranges for 90% and 80% satisfied occupants for fully mechanically controlled (HVAC) and for naturally ventilated (NV) environments

47. Adaptive Models
Adaptive thermal comfort diagram for naturally ventilated environments, adopted into ASHRAE Standard 55/2004

48. Adaptive Models
Indoor operative temperature vs outdoor mean running temperature for buildings without mechanical cooling systems
t ORM(n) = (1 – α) ( t OMD(n-1) + α t OMD(n-2) + α2 t OMD(n-3) + ….)
t ORM(n) running mean temperature in the day n
t ODM(n) outdoor daily mean temperature in the day n

49. Indoor Air Quality
An indicator of the types and amounts of pollutants in the air that might cause discomfort or risk of adverse effects on human or animal health, or damage to vegetation
Air quality is usually referenced to the concentration in air of one or more pollutants. For many pollutants, air quality is expressed as an average concentration over a certain period of time, e.g., μg/m3 averaged over 8 hours
(In ISIAQ Glossary of Indoor Air Sciences, 1st ed, 2006)

50. IAQ Triangle Concentrations of Pollutants IAQ
Effects in Health and Comfort
Generation of Pollutants
Air Processing

51. Poluentes deposited or absorpted
Variation of Concentration
Emitted Pollutants
Pollutants entering
Pollutants leaving
Removed pollutants

52. Basic Equations
Charging Fase C0
Cequi
Decay Fase

53. Definition of Ventilation Requirements
Cequi
Cavg
Parameter
Condition
Method
Fresh Air Flow Rate or
Air Exchange Rate
Cequi < Cref
Prescriptive
Cavg < Cref
Analytical

54. Basis of the Prescriptive Methods
C0 = Cext
Cequi as

55. Basis of the Prescriptive Methods
Clim <1000 ppm
Q > 30 m3/(h.person)
NOTE: Curve for the CO2 generation of CO2 of a standard person (P50%) with 1.2 met matabolic rate

56. Example of a Prescriptive Method
Minimum Fresh Air Flow Rate
G[CO2 ]= [(mg/h) / met] x M [met]
1 person percentil 50 (70kg, 1,7m)
Cext = 680mg/m3

57. Metabolic Rate- M (met) Fresh Air Flow Rate [m3/(hora.person)]
Example of a Prescriptive Method
Type of activity
Metabolic Rate- M (met)
Type of Space
Fresh Air Flow Rate [m3/(hora.person)]
Sleeping
0,8
Bedrooms, Dormitories, etc. 16
Resting 1
Resting rooms, Waiting Rooms, Conferene Rooms, Auditoriums 20
Sedentary
1,2
Offices, Libraries, Schools 24
Moderate
1,75 (1,4 a 2,0)
Laboratories Ateliers, Drawing Rooms, Cafés, Bars, 35
Slightly High
2,5 ( 2,0 a 3,0)
Dance Floors, Gymnasium rooms, Ballet rooms 49
High
5,0 ( 3,0 a 9,0)
Bodybuilder rooms, Sport facilities, etc 98

58. Daily Average Concentrations
Analytical Method
It is performed a simulation of the time evolution of the concentration during the occupancy period, using a finite diferences equation, to calculate the dose at which occupants are exposed.
Category
Daily Average Concentrations
CO2
Special Req
1600 mg/m3
900 ppm
Normal
2250 mg/m3
1250 ppm

59. Analytical Method
Software Tool version with Percentage of Occuppancy Input

60. Analytical Method
Software Tool version with Table Input Data

61. Monitoring Buildings. Why
"If you don't measure it, you can't manage it"
Buildings and Building Systems are too much complicated to understand with simple one-shot measurements, on account of the large number of relevant parameters with strong time and space variability.

62. Case Study
A Business Park in the municipality of Oeiras, at the metropolitan area of Lisbon, Portugal, 3 Km away from the sea coast. The building has three floors for offices (7000 m2) and three underground floors for parking (8000 m2)

63. Studied Office building
Wireless network with 49 counters for electrical energy, 15 indoor environmental quality monitoring stations (concentration of CO2, air temperature, relative humidity, VOCs level) and one outdoor weather station

64. Monitoring and Consulting Services
Web Based Monitoring Solution Concept
Metering
System
Data Reduction & Analysis
Web Server
Data Base
Sensors
Router
Structured Knowledge
Techn Management
BUILDING
Monitoring and Consulting Services

65. Web Tool - Dashboard

66. Web Software Tool – CO2 Data

67. CO2 and Wind Speed Time Series

68. Data analysis
(Month map of CO2 Concentration)

69. Data analysis
(Month maps of Air temperature and Rel. Humidity)

70. Electrical Energy Data (week graph)

71. Electrical Energy Data (24 h data)

75. Greening Buildings
Change of occupants habits, Redefinition of set points of indoor target conditions
Change of control routines, Management of Solar Gains through Shadowing Solutions
Improvement of Wall Insulation and Characteristics of Glazing Areas
Controlled Ventilation (DCV, e. g. with CO2 sensors or time programmed)
Night free cooling, Tunning of Infiltration, Hybrid and Natural Ventilation
Smart Management of Lighting (conjugation of natural and artificial lighting, low consumption lamps, occupancy sensors, etc.)
Use of solar thermal collectors for domestic hot water and indoor environment heating
Improvement of performance of HVAC systems. Energy recovery solutions
Photovoltaics for electrical energy Production, Thermal Energy Storage Solutions
Management of active and idle periods of electric devices. Reduction of stand-by consumptions