mixed mode (hybrid) ventilation - ghdonline€¦ · library car parking roof garden 119.5m rain...
TRANSCRIPT
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Mixed Mode Mixed Mode (Hybrid) (Hybrid)
VentilationVentilationHal LevinHal Levin
Building Ecology Research GroupBuilding Ecology Research Group
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IEA Annex 35 -- HybVent Buildings
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Shares of Non-ResidentialBuilding Energy Use
0% 5% 10% 15% 20% 25%
Percent of non-residential total
Office
Warehouse/Storage
Mercantile
Education
Public Assembly
Lodging
Service
Health Care
Food Service
Public Order/Safety
Food Sales
Vacant
Other
Primary Energy Use
Total Floorspace
Healthcare
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Natural and Mixed Mode Ventilation Mechanisms
Courtesy of Martin Liddament via Yuguo Li
Mixed Mode Ventilation
Sketch of school systemSketch of B&O Building
Natural Ventilation
Cross Flow Wind
Mixed Mode Ventilation
Wind Tower Stack (Flue) Stack (Atrium)
Fan Assisted Stack
heated/cooledpipes
heated/cooledceiling void
Top Down Ventilation
chilled pipes
Buried Pipes
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Main Hybrid Ventilation Principles
• Natural and mechanicalventilation
• Fan-assisted natural ventilation
• Stack and wind-assisted mechanical ventilation
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Ventilation for Indoor Air Quality Control
• When optimizing ventilation for indoor air quality control, the challenge is to achieve an optimal equilibrium between indoor air quality, thermal comfort, energy use and environmental impact during periods of heating and cooling demands.
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Pollutant concentration as a function of outdoor air exchange rate
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0 1 2 3 4 5Ventilation air changes per hour (ach)
Con
cent
ratio
n (µ
g/m
3 )
EF = 1 µg/m2•hr
EF = 5 µg/m2•hr
EF = 10 µg/m2•hr
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Nardell et al, 1991, Am Rev Resp Dis
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Local ventilation - exhaust
Design Drawing Prototype in the test room
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Decay of droplet nuclei concentration in an isolation room for different ventilation rates and duration of time
Ventilation rate Time (minutes)
6 ACH 9 ACH 12 ACH 15 ACH 18 ACH 21 ACH 24 ACH
0 100.00% 100.00% 100.00% 100.00% 100.00% 100.00% 100.00%
5 60.65% 47.24% 36.79% 28.65% 22.31% 17.38% 13.53%
10 36.79% 22.31% 13.53% 8.21% 4.98% 3.02% 1.83%
15 22.31% 10.54% 4.98% 2.35% 1.11% 0.52% 0.25%
20 13.53% 4.98% 1.83% 0.67% 0.25% 0.09% 0.03%
25 8.21% 2.35% 0.67% 0.19% 0.06% 0.02% 0.00%
30 4.98% 1.11% 0.25% 0.06% 0.01% 0.00% 0.00%
35 3.02% 0.52% 0.09% 0.02% 0.00% 0.00% 0.00%
40 1.83% 0.25% 0.03% 0.00% 0.00% 0.00% 0.00%
45 1.11% 0.12% 0.01% 0.00% 0.00% 0.00% 0.00%
50 0.67% 0.06% 0.00% 0.00% 0.00% 0.00% 0.00%
60 0.25% 0.01% 0.00% 0.00% 0.00% 0.00% 0.00%
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IAQ-Energy Trade-off
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ACH can be misleading?
V=10 m3 V=10 m3
V=30 m3
V=10 m3
q=30m3/h
q=1 ach
q=30m3/h
q=1 ach
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Ventilation for Temperature Control
• When optimizing ventilation as a natural cooling strategy, the challenge is to achieve an optimal equilibrium between cooling capacity, cooling load, thermal mass and thermal comfort.
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ASHRAE Std. 55-2004Adaptive vs. Static Comfort Model:
Comparison of adaptive models’ predicted indoor comfort temperatures with predictions by the “static” PMV model.
buildings with natural ventilation
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-5 0 5 10 15 20 25 30 35
mean outdoor effective temperature (oC)
com
fort
tem
pera
ture
(o C
)
RP-884 adaptive model"static" model (PMV)
buildings with centralized HVAC
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-5 0 5 10 15 20 25 30 35
mean outdoor effective temperature (oC)
com
fort
tem
pera
ture
(o C
)
RP-884 adaptive model with semantics
"static" model (PMV)
CENTRALLY-CONTROLLED HVAC SYSTEMS
NATURALLY VENTILATED BUILDINGS
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Adaptive Model Research:Brager and de Dear
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Low Energy Cooling Technologies
• Night cooling (natural ventilation)• Night cooling (mechanical ventilation)• Slab cooling (air)• Slab cooling (water)• Evaporative cooling (direct and indirect)• Desiccant and evaporative cooling• Chilled ceilings/beams• Displacement ventilation• Ground cooling (air)• Aquifer• Sea/river/lake water cooling
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Types of HybVent Components
• There are no real hybrid ventilation components as such.
• In nearly all cases hybrid ventilation systems consist of a combination of components, which can be used in purely natural systems or in purely mechanical systems.
• However, the availability of appropriate components is essential for the successful design and operation of a hybrid ventilation system.
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Ventilation SystemsAll houses need ventilation, while traditionally this is done bypassive trickle vents above windows, often some form of mechanical ventilation may be needed. Simple bathroom extracts can be driven from the lighting circuit, but these simply throw away the warm air. Heat Recovery Ventilation Units extract the heat from the extract air and use this to warmthe incoming fresh air saving energy.
Natural or Passive Ventilation schemesSome houses employ Natural Ventilation techniques, using the buoyancy of warm air to create the “stack effect”, enhancing ventilation through a wind tower. Such schemes employ automatic opening windows or vents at low and high level, which must be inhibited during high winds, etc.
Typically, our solution will feature:a small “smart Box” panel with the smart Module near to the motorised windows a weather station with wind speed and direction can inhibit the opening of windows under certain conditions a rain sensor may also be fitted
http://www.smartkontrols.co.uk/cooling_overview.htm
SmartKontrols technology
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To combine natural and mechanical forces in the air distribution system, components can include:
• Low-pressure ductwork (size, surface, angles)• Low-pressure fans with advanced control mechanisms such as frequency control, air flow control, etc…• Low-pressure static heat exchangers and air filters (filter s.p. relates to filter efficiency, e.s.)• Wind towers, solar chimneys or atria for exhaust.• Underground ducts, culverts or plenums to pre-condition supply air.
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For control of thermal comfort, indoor air quality and air flow, components can include:
• Manually operated and/or motorized windows, vents or special ventilation openings in the facade- and in internal walls,
• Room temperature, CO2 and/or air flow sensors,• A control system with weather station
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Local air movement fans
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BRE Environmental Office (1997)
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BRE’s Environmental Office Building
• Low energy fans for use on still air days
• Glass for solar heating of thermal chimney
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BRE Environmental Office Building: Ventilation and Cooling
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Wind floor on 18FWind floor on 18F
The 1st Hybrid Vent. for High rise Bldgsin JapanThe 1st Hybrid Vent. for High rise Bldgsin Japan
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Entrance Hall on 1FEntrance Hall on 1F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Memorial Hall on 23FMemorial Hall on 23F
Memorial Hall on 23F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Graduate School on 19-22FGraduate School on 19-22F
Graduate School on 19 - 22F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Natural Ventilation Shafts for 19-22FNatural Ventilation Shafts for 19-22F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Canteen on 17FCanteen on 17F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Lecture Rooms on 6-16F & B1-3FLecture Rooms on 6-16F & B1-3F
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Typical lecture room floorTypical lecture room floor
Lecture Rooms
Escalator
Refresh SpaceWC WC
M/RM/R
Wind is exhausted at the top of Wind is exhausted at the top of Escalator (Wind floor on 18th level)Escalator (Wind floor on 18th level)
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Entrance Hall on 1FEntrance Hall on 1F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Gymnasium on B3FGymnasium on B3F
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Wind floor 18F
Memorial Hall
Entrance Hall
Lecture Rooms
Graduate School
Offices
Library Car Parking
Roof Garden
119.5m
Heat Storage TankRain Water Tank
Canteen
Roof Garden
Library B3-1FLibrary B3-1F Day-lighting even on B3F
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Library B3-1FLibrary B3-1F Day-lighting even on B3F
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To improve Indoor Air Quality and Save Energy To improve Indoor Air Quality and Save Energy
- Automatically controlled natural ventilation windows and wind floor (18F) design. - Night-purge of VOCs and Internal heat- Variable fresh air intake using CO2 sensor - BEMS
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Hybrid Ventilation SystemHybrid Ventilation System
VAV
Air Handling Unit(Middle season:all fresh air conditioner)
Lecture Room
NaturalVentilation Conditioned Air
To each Class RoomReturned Air
EscalatorHall
Fresh Air
Exhausted AirFrom each Class Room
To Wind Floor (18th level)
Motor Damper
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SensorsSensors
Anemometer,State of natural ventilation window (open or close),Integrated time while windows are open
T H
T
T
HOutdoor
Solar radiationRainfall
Wind speed at exhaust opening
Thermometer
T
H Hygrometer
V
Anemometer
Wind speed & direction
V
V
VV
V
COdensity
2
T
These data (total 2000 points) are recorded automatically every 10 minutes
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0
2 0 0
4 0 0
6 0 0
8 0 0
1 ,0 0 0
1 ,2 0 0
1 ,4 0 0
1 ,6 0 0
1 ,8 0 0
B3F
B1F 2F 4F 6F 8F 10
F
12F
14F
16F
18F
20F
22F
23F
時間
/年
2 0 0 0 / 3
2 0 0 0 / 2
2 0 0 0 / 1
1 9 9 9 / 1 2
1 9 9 9 / 1 1
1 9 9 9 / 1 0
1 9 9 9 / 9
1 9 9 9 / 8
1 9 9 9 / 7
1 9 9 9 / 6
1 9 9 9 / 5
1 9 9 9 / 4
Ventilation windows were opened for 1100 hours per yearVentilation windows were opened for 1100 hours per year
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Apr.1999-Mar.2000
Hybrid Ventilation System reduced Space Cooling Energy by 17%Hybrid Ventilation System reduced Space Cooling Energy by 17%
0102030405060708090
Apr May Jun Jul Aug Sep Oct Nov
Prim
ary
Ener
gy C
onsu
mpt
ion
for
Spac
e C
oolin
g(M
J/m
2)Reduced by Natural VentilationAir-handlingChilling
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Operation Energy was reduced by 40%Operation Energy was reduced by 40%
0
500
1000
1500
2000
2500
3000
Reference Case Study Actual
Prim
ary
Ener
gy C
omsu
mpt
ion[
MJ/
a/m
2]
Cooking
Escalat or
Elevat or
Elect r ic Applances
Light ing
Air Handling
HeatSource(Ot hers)Heat Source(St orage)
1,5831,647
2,696 Apr. 1999 – Mar. 2000
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LCCO2 will be reduced by 40%LCCO2 will be reduced by 40%
0 50 100 150 200 250
Case Study
Reference
Design Intial ConstructionRe-construction RepairRenovation MaintenanceOperating Energy DemolitionRelease of HCFCs
-37%kg-CO2/a/m2
127.9
202.1
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Eco-Economic AnalysisEco-Economic Analysis
4750372.6 88.8234.7Total
10005719.2 2.956.5Natural Ventilation
611541.0 9.49.4Variable Water Volume
102900.5 5.92.9Escalator control
05950.0 5.40Thermal Heat Strage
709563.9 17.266.9Variable Air Volume
569663.0 18.054.1CO cont. for Parking Vent.
329811.6 19.631.4Day Lithting Hf lamp
1310381.3 10.413.5CO2 cont. for Fresh air Intake
Intial costper unit CO2Reduction(1000 yen/(t-CO2/year))
CO2Reduction
(t-CO2/Year)
CostPaybacktime(Year)
Energycostreduction(MillionYen/year)
Initial cost(Million
Yen)
1999, 2000
234.7 / 20000 Million Yen= + 1.2%
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Additional Initial Cost {Yen/(t-CO2/a)}
47,000JPY/(t-CO2/a)
Photo Voltaics
Eco-Economic AnalysisEco-Economic Analysis
4,000,000JPY/(t-CO2/a)
234.7 / 20000 Million JPY = + 1.2%
Meiji University
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Official Annex 35 report summarizes initial working phase of the project.
• Ventilation technologies• Control strategies and algorithms• Analysis methods• Examples of existing systems• Solutions to problems in different
climates.
• Available at http://hybvent.civil.auc.dk/puplications/sotar.pdf
(135 pages)
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Annex 35 HybVent Publications are available for download at http://hybvent.civil.auc.dk/