1. Dr Nigel Blades UCL Centre for Sustainable Heritage UCL CENTRE FOR SUSTAINABLE HERITAGE Application of an Air Pollution Modelling Tool to Cultural Heritage Buildings

2. IMPACT pollution model - JAVA applet implementation of pollution mass balance equation of Weschler et al. (1989) Model outputs: –Indoor pollutant concentration or I/O ratio –Which surfaces absorb most pollutant –Relation between I/O ratio and ventilation rate

3. Case study 1: Sainsbury Centre for Visual Arts, Norwich, UK Metal walls and ceiling Glass end walls Open plan display area Mechanical ventilation but not air conditioning Close relation to outdoor environment

4. Sainsbury Centre for Visual Arts Table 1: Data on the SCVA used in the modelling Internal surfacesArea m 2 Other parameters Metallic wall finish2620Room volume42570 m 3 Metallic ceiling finish4585Air change rate1.5ach Glass528Temperature20°C Carpeted floor4257Relative humidity55% Inner wall insulation2064

5. IMPACT modelling of the SCVA Model scenarioSulphur dioxide Nitrogen dioxide Ozone (a) SCVA without interventions0.890.870.88 How can pollution control be improved at the SCVA?

6. IMPACT modelling of the SCVA Model scenarioSulphur dioxide Nitrogen dioxide Ozone (a) SCVA without interventions0.890.870.88 (b) Reduce ventilation rate to 0.3ach0.760.78 (c) Introduce enhanced pollution absorbing paint 0.720.700.72 (b) and (c) combined0.62

7. Case study 2: Factory building converted into an archive store Concrete walls and floors Most glazing covered over Naturally ventilated, but building tightly sealed Door to outside Entrance lobby Internal doors Stair well modelled zone

8. Data used to model the archive store SurfaceArea m 2 Other parameters Concrete wall582Room volume7972m 3 Chipboard window covers214Air change rate0.3 ach Synthetic flooring1355Temperature20°C Concrete ceiling1355Relative humidity55% Exposed paper and book boards6934

9. IMPACT modelling of nitrogen dioxide at the archive store

10. IMPACT modelling of the archive store – results for all gases PollutantModelled I/O ratio Nitrogen dioxide0.46 Ozone0.24 Sulphur dioxide0.33

11. IMPACT modelling of the archive store – results for all gases PollutantModelled I/O ratio Nitrogen dioxide0.46 Ozone0.24 Sulphur dioxide0.33 Is this good for conservation of the collection?

12. IMPACT modelling of the archive store – pollution effects on the collection PollutantModelled I/O ratio (with collection) Modelled I/O ratio (no collection) Nitrogen dioxide0.460.78 Ozone0.240.73 Sulphur dioxide0.330.60

13. IMPACT modelling of the archive store – comparison with measured data PollutantModelled I/O ratioMeasured I/O ratio Nitrogen dioxide0.46 0.24 Ozone0.24 0.1 Sulphur dioxide0.33 0.4

14. Reasons for discrepancy between measured and modelled data Amount of active surface area in the building has been underestimated Single zone model does not allow for air infiltration from other zones (rooms) Enhanced pollution deposition around cracks and crevices where air infiltrates Homogeneous chemistry?

15. Conclusions IMPACT model can quickly and easily estimate the contribution of outdoor pollution to indoor environment, using a simple deposition model Help understand relation between air pollution and buildings Teaching aid for conservators in UK and Malta, COST G8 Training School In use by heritage organisations, e.g. English Heritage

16. European project details IMPACT, Contract No. EVK4-CT-2000-00031, ‘Innovative Modelling of Museum Pollution and Conservation Thresholds’ (2000-04) http://www.ucl.ac.uk/sustainableheritage/impact