Designing natural ventilation for thermal comfort in buildings

Transcription

1 Designing natural ventilation for thermal comfort in buildings T F

2 full AC Typical Energy Use In Buildings Source: Baker and Steemers

3 HOUGHTON HALL

4 HOUGHTON HALL CONSERVATION AREA ADJOINING BUSINESS PARK PLOT

5 HOUGHTON HALL

6 HOUGHTON HALL Concrete soffits Trickle vents PASSIVE VENTILATION AND SOLAR CONTROL TECHNIQUES

7

8 Complex Spaces Houghton Hall

9 Temperature/C Temperature Measurements First 1 floor 3-21 July 2003 North side of the atrium East end of the atrium South side of ext temp the atrium H 144 West end of the H 145 atrium (dark blue line, very H small peak) H Within main H146 floor H 147 Atrium peak H 148 temperatures follow exposure to sun Jul 13-Jul 14-Jul 14-Jul 15-Jul 15-Jul 16-Jul Time Region near/within atrium hotter than desk area under exposed concrete benefit of thermal mass

10 Temperature/C Temperature Measurements 3-21 July Average temperatures ext temp GF FF SS FF NS SF Main floor temperatures less than outside and buffered by thermal mass but still rather warm mid-july Jul 8-Jul 13-Jul 18-Jul Time

11 Temperature/C Temperature Measurements July-14Aug average temperatures Warm inside again in early August outside GF FF SS FF NS SF Jul 28-Jul 2-Aug 7-Aug 12-Aug Time

12 Temperature/C Temperature Measurements 15Aug-10Sept Average temperatures 40 Cooler after mid-august Aug 20-Aug 25-Aug 30-Aug 4-Sep 9-Sep Time outside GF FF SS FF NS SF

13 rating scale- average responses & standard error of the mean Survey Results U N S A T I S F A C T O R Y S A T I S F A C T O R Y spring: 26 responses summer : 24 responses fall: 44 responses winter:40 responses c 3g THERMAL COMFORT INDOOR AIR QUALITY PERSONAL CONTROL OVERALL HEALTH OVERALL COMFORT AVERAGE RESPONSE RATE > 50% CONFIDENCE LEVEL FOR STANDARD ERROR 'p'= 0.05

14 Temperature/C Can we improve performance? 23July-14Aug average temperatures outside GF FF SS FF NS SF Jul 28-Jul 2-Aug 7-Aug 12-Aug Time

15 Time lag (hr) Time Lags Jun 18-Jul 07-Aug 27-Aug 16-Sep -2 tmin lag tmax lag -3 Date Range of time lag for building to reach max or min temp

16 Frequency August-Sep Grd S 1st S 1st N 2nd N <0 0 to 1 1 to 2 2 to 3 3 to 4 >4 Buffer for max temp 1-3 hours Delay (hrs)

17 temperature (C) Maximising Effectiveness of Thermal Mass Toutside Tconcrete T air internal T perceived time (hrs)

18 Air Flow Results Hot and still day (06/08/03) Fans are operating all day All windows open

19 Air supply (l/spp) Air Quality Houghton Hall Required Measurements show fresh air supply well in excess of minimum required

20 Temperature/C Night Time Operation Limited number of trickle vents open :00 4:00 8:00 12:00 16:00 20:00 0:00 Time Upper part of atrium (2nd floor) outside Second floor

21 Opportunity for Improvement July outside air temperature. 45 August outside temperature Jun 3-Jul 8-Jul 13-Jul 18-Jul 23-Jul 28-Jul 2-Aug 7-Aug 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 night even more effectively to reduce building temperature 2. Reduce window openings during summer day to maximise benefit of thermal mass

22 Contact Theatre, after renovation

23 Contact Theatre, Studio Temperature (C) external 15 top of theatre September 06 September 07 September 08 September 09 September 10 September Date

24 Ltd. Belvoir High School BB101 Standards 120 hours for which T room >28 o C (T room ) max = 32 o C (T room T external ) max = 5 o C Belvoir High School 0 hours for which T room >28 o C (T room ) max = 27.5 o C (T room T external ) max = 2.3 o C

25 Ltd. Internal Comfort

26 Ltd. Hybrid Designs

27 Ltd. Summary Natural ventilation low energy Exposed thermal mass Fan driven ventilation not free cooling