This is closely related to my field of work, so I feel the need to be pedantic. Please note my criticisms should not be taken to knock the thrust of the work i

This is closely related to my field of work, so I feel the need to be pedantic. Please note my criticisms should not be taken to knock the thrust of the work itself. The research question had to do with social effects, while I am criticizing the modeling behind the infiltration estimates. First of all, the "stack effect" is not the most important driver of flow in modern buildings (especially not ones that have revolving doors). Mechanical systems are designed to dominate stack and wind-driven flows, precisely because engineers want to control the flows in the building. The analysis presented on the web page and in the research report discussed only stack and wind effects. Second, the equations shown in the figure on the web page are from a steady-state "multizone" modeling approach. Steady-state models don't represent swinging doors well, because of several important transient effects: (1) momentum effects associated with the intermittent nature of the flow (makes airflow smaller than a steady-state model would suggest; and (2) active pumping by the door (makes airflow larger than a passive transient model would suggest). Third, I think the blanket statement that "heating is less efficient than cooling" is just flat-out wrong. Heating is pretty easy-- just plug in a lightbulb, and 100% of the electricity it burns gets converted to heat. For this reason, many buildings have core zones that require cooling year-round. Fortunately, I don't think any of these criticisms affect the broad validity of the work. Their modeling seems to have been driven largely by experimental studies, not by the material described on their web page and in their paper. Therefore one can assume they got the right order of magnitude (one might also note that the cited papers are from 1958 and 1961-- in other words, the basic technical part here is not new, and it's unlikely they botched it too badly). One final criticism. MIT has a very good faculty that specializes in building energy issues. Any of them could have pointed out these problems, and helped guide a much stronger technical analysis. Unfortunately, none of that faculty seems to have been consulted for this study (the acknowledgments list a bunch of urban studies and management faculty, plus people from the facilities department). I know this was just a class exercise, but it seems to me representative of the sorts of analyses that can result when management people start mucking about in technical matters...