Bideford College: A Low Carbon School Case Study Dan Lash Regen SW 1 October 2008
Project Description • • • • •
£40 million secondary school in North Devon Approx 17,000 m²,1800 pupils Specialism in Science Designed by NPS (architect, engineer, QS) Sustainability (and acoustic) design consultancy by CEE • BREEAM Excellent target
DCSF Case Study ‘Green Book’
Main Energy Premise
Reduce energy demand through intelligent design, and meet the remainder with clean energy
The Initial Design
A Revised Design
The Concept Refined
Early Thermal Modelling: A simple classroom-corridor block
N S
Early Thermal Modelling: Tabulated corridor temperature statistic output for 9 scenario’s Sim no.
Ventilatio n
1 2 3 4
NCM Macroflo Macroflo Macroflo
Window s open at n/a 25°C 19°C 19°C
5
Macroflo
19°C
6
Macroflo
19°C summer, 25°C winter 19°C summer, 25°C winter 19°C summer, 25°C winter 19°C summer, 25°C winter
7
8
9
Macroflo
Macroflo
Macroflo
Opening area
n/a Whole façade Whole façade 2m strip top and bottom 2m strip top and bottom 2m strip top and bottom
Sngl/Dbl glazed
28°C
D D D
0.3% 1.2% 0.9%
27.2% 69.2% 43.6%
65.7% 1.0% 0.4%
D
0.8%
51.6%
2.3%
S
4.1%
41.4%
1.7%
D
1.1%
65.1%
2.3%
D
1.2%
70.6%
0.5%
S
9.4%
54.0%
0.1%
S
8.8%
53.4%
1.7%
Whole façade
Whole façade
2m strip top and bottom
Early Thermal Modelling: Probability of corridor temperature occurrence 9am-5pm for modelled scenario’s 1
2
3
4
5
6
7
8
9
external
100% 90% 80% 70% 60%
#9 #7 53% 71%
50% 40% 30% 20% 10%
#1 27%
0% 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 temperature
200
Early Thermal Modelling: Typical heat flows in corridor
65 60
150
55 50
100 Gain (kW)
40
50
35 0
30 25
-50
20 15
-100
10 -150 Mon
Tue
Wed
Thu
Fri
Date: Mon 05/Feb to Fri 09/Feb Space conditioning sensible: circulation (18.aps)
Internal gain: circulation (18.aps)
Solar gain: circulation (18.aps)
External conduction gain: circulation (18.aps)
Internal conduction gain: circulation (18.aps)
Aux vent gain: circulation (18.aps)
Natural vent gain: circulation (18.aps)
Infiltration gain: circulation (18.aps)
Free cooling vent gain: circulation (18.aps)
MacroFlo ext vent gain: circulation (18.aps)
MacroFlo int vent gain: circulation (18.aps)
Air temperature: circulation (18.aps)
5 Sat
Temperature (°C)
45
Looking at other spaces – The winter gardens
1 5
Ju n
12 : 0 0
N
sun
View time = 15 Jun 12:00 Site Latitude = 50.73 Longitude diff. = -3.42 Model Bearing = 0.00 Sun: azi = 173.08 alt = 62.45 Eye: azi = 140.00 alt = 40.00
e ey
Suncast image:
Air Flow in & out high level vent on west facade 350
50000
24000
350
16
22000
45000
14 300
300 20000 40000 18000
250
12 250
35000 16000
10 30000
10000
20000
Azimuth (deg.)
Volume flow (l/s)
Azimuth (deg.)
12000
200
8
Speed (m/s)
25000
150
14000 Volume flow (l/s)
200
150 6
8000 15000
100
100 6000
4
10000 4000 50
50 2 5000
0 00:00
06:00
12:00
2000
0 00:00
18:00
0
0 00:00
06:00
Date: Mon 04/Jun Wind direction(E of N): (24.aps)
12:00
18:00
0 00:00
Date: Fri 10/Aug
Volume flow in: (External window)
Volume flow out: (External window)
350
Volume flow in: (External window)
Volume flow out: (External window)
Wind speed: (19.aps)
Wind direction(E of N): (19.aps)
50000
45000 300
Wind direction
40000
250
35000
Wind speed
30000 Azimuth (deg.)
25000
150 20000
Volume flow (l/s)
200
Flow in
15000
100
10000 50 5000
0 00:00
06:00
12:00
0 00:00
18:00
Date: Fri 29/Jun Wind direction(E of N): (24.aps)
Volume flow in: (External window)
Volume flow out: (External window)
Flow out
A week in the summer external temp
top east strip closed
top east strip opens
40 35
temperature
30 25 20 15 10 5 0 30/07/2007
31/07/2007
01/08/2007
02/08/2007
03/08/2007
04/08/2007
A Week in December Kalwall .29 thermally broken
Double glazed g-0.46
external temperature
14
12
temperature
10
8
6
4
2
0 01/12/2006
06/12/2006
11/12/2006
16/12/2006
21/12/2006
26/12/2006
31/12/2006
Control Strategies • EMS with summer/winter mode (thermal) • Ventilation on CO2 in winter (< 1500 ppm), temp in winter (
