designing natural ventilation for thermal comfort in … from uk...23july-14aug average temperatures...

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Designing natural ventilation for thermal comfort in buildings

©Breathing Buildings

Energy Use In Buildings

Typi

cal

Source: Baker and Steemers

full A

C

HOUGHTON HALL

HOUGHTON HALL CONSERVATION AREA

ADJOINING BUSINESS PARK PLOT

HOUGHTON HALL


HOUGHTON HALL

PASSIVE VENTILATION AND SOLAR CONTROL TECHNIQUES

Trickle vents

Concrete soffits



Complex Spaces – Houghton Hall

Atrium peak temperatures follow exposure to sun

Region near/within atrium hotter than desk area under exposed concrete benefit of thermal mass

10

15

20

25

30

35

40

13-Jul 13-Jul 14-Jul 14-Jul 15-Jul 15-Jul 16-JulTime

Tem

pera

ture

/C• North side of

the atrium

• East end of theatrium

• South side ofthe atrium

• West end of theatrium (darkblue line, verysmall peak)

• Within mainfloor

1st floor


Temperature Measurements

3-21 July Average temperatures

5

10

15

20

25

30

35

40

3-Jul 8-Jul 13-Jul 18-JulTime

Tem

pera

ture

/C ext tempGF FF SSFF NSSF

Main floor temperatures less than outside and buffered by thermal mass…

but still rather warm mid-July



23July-14Aug average temperatures

5

10

15

20

25

30

35

40

23-Jul 28-Jul 2-Aug 7-Aug 12-AugTime

Tem

pera

ture

/C outsideGFFF SSFF NSSF

Warm inside again in early August



15Aug-10Sept Average temperatures

5

10

15

20

25

30

35

40

15-Aug 20-Aug 25-Aug 30-Aug 4-Sep 9-SepTime

Tem

per

atur

e/C

outsideGFFF SSFF NSSF

Cooler after mid-August



3.273.08 3.08

4.58

2.76

4.17

5.01

4.00

5.13

4.32

5.39

3.43

3.132.93

3.70

3.27

4.58

3.08 3.08

2.76

1

2

3

4

5

6

7

1c 3g 7 8 10THERMAL COMFORT INDOOR AIR QUALITY PERSONAL CONTROL OVERALL HEALTH OVERALL COMFORT

ratin

g sc

ale-

ave

rage

resp

onse

s &

sta

ndar

d er

ror o

f the

mea

n

spring: 26 responses summer : 24 responses fall: 44 responses winter:40 responses

SATISFACTORY

UNSATISFACTORY

AVERAGE RESPONSE RATE > 50%CONFIDENCE LEVEL FOR STANDARD ERROR 'p'= 0.05

Survey Results

23July-14Aug average temperatures

5

10

15

20

25

30

35

40

23-Jul 28-Jul 2-Aug 7-Aug 12-AugTime

Tem

pera

ture

/C outsideGFFF SSFF NSSF

Can we improve performance?


-3

-2

-1

0

1

2

3

4

5

6

28-Jun 18-Jul 07-Aug 27-Aug 16-Sep

Date

Tim

e la

g (h

r)

tmin lagtmax lag

Range of time lag for building to reach max or min temp


Time Lags

Buffer for max temp 1-3 hours

August-Sep 2003

0

2

4

6

8

10

12

14

<0 0 to 1 1 to 2 2 to 3 3 to 4 >4

Delay (hrs)

Freq

uenc

y Grd S1st S1st N2nd N



Maximising Effectiveness of Thermal Mass

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60 70

tem

pera

ture

(C)

time (hrs)

ToutsideTconcreteT air internalT perceived

•Hot and still day(06/08/03)

•Fans are operating all day

•All windowsopen

Air Flow Results


0

10

20

30

40

50

60

Houghton Hall Required

Air

supp

ly (l

/spp

)

43-60

8

Measurements show fresh air supply well in excess of minimum required

Air Quality

5

10

15

20

25

30

35

40

45

0:00 4:00 8:00 12:00 16:00 20:00 0:00Time

Tem

pera

ture

/C

Upper part of atrium (2nd floor)

outside Second floor

•Limited number of trickle vents open


Night Time Operation

July outside air temperature.

5

10

15

20

25

30

35

40

28-Jun 3-Jul 8-Jul 13-Jul 18-Jul 23-Jul 28-Jul 2-Aug

August outside temperature.

5

10

15

20

25

30

35

40

45

28-Jul 2-Aug 7-Aug 12-Aug 17-Aug 22-Aug 27-Aug 1-Sep 6-Sep

1. Opportunity to use cool air from outside during nighteven more effectively to reduce building temperature

2. Reduce window openings during summer day tomaximise benefit of thermal mass

Opportunity for Improvement


Contact Theatre, after renovation

Contact Theatre, Studio


0

5

10

15

20

25

30

05 September 06 September 07 September 08 September 09 September 10 September

Tem

pera

ture

(C)

Date

external

top of theatre


Belvoir High School

©Breathing Buildings Ltd.

Belvoir High School 0 hours for which Troom>28oC (Troom) max = 27.5oC (Troom – Texternal)max = 2.3oC

BB101 Standards 120 hours for which Troom>28oC (Troom) max = 32oC (Troom – Texternal)max = 5oC


Internal Comfort



Hybrid Designs



Summary


• Natural ventilation low energy

• Exposed thermal mass

• Fan driven ventilation not “free cooling”

designing natural ventilation for thermal comfort in … from uk...23july-14aug average temperatures...

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