Keeping our indoor environment comfortable and healthy is important- we spend most of our time indoors, and it is here that we often get our highest exposure to unhealthy air- through infiltration of outdoor pollution, generation of indoor pollution, and transmission of airborne pathogens. Some ventilation systems are better than others in promoting healthy indoor air quality. These are challenging design and modelling problems, as highlighted in work by Aliabadi from our group.
Heating, ventilation and air-conditioning uses about as much energy as transportation – and there are large opportunities here! In practice, buildings often do not function as well as other engineered systems that we might be familiar with. If a car emits twice as much as predicted, it is a huge scandal. If a building uses twice the predicted energy, it is “normal”.
The Energy and Aerosols Laboratory is tackling one part of the challenge to design better buildings: ventilation. Recent work with Green and Montgomery found optimal (health vs energy) strategies for the use of filters in buildings. Currently we are working with dPoint Technologies to improve energy recovery ventilators. This work provides practical information on when (and how) air pollution may degrade the performance of energy recovery ventilators (ERV).
Results and Significance
Work with Montgomery et al found that, in contrast with standard HVAC design practice, the optimal design of filtration system depends on local air quality, local energy and labor costs, and stakeholder goals.
An interesting finding of the laboratory filter studies was that very small changes in relative humidity, well below deliquescence, could cause restructuring of the filter deposits, substantially altering the flow resistance and filtration efficiency.
Current research on the aerosol fouling of ERVs indicates that fine soluble solid particles can reduce moisture transport through membrane ERVs.