The Study
In order to create the statistical foundation for
Greentrofit™,
our team conducted a local study of air exchange rates of homes in the Princeton,
NJ area. We performed over 40 assessments using a an apparuts called a
blower door.
This method uses a fan to depressurize the indoor area of the house envelope, then
varies the fan flow rate and records a range of pressure differences between indoor
and outdoor environments. Corresponding fan flow rates are collected and then
fed into a calculator created by team members, which determines the leakiness of
the house, including natural infiltration rate.
To supplement the data collected from the blower door tests, the
team gathered data on a number of house factors that could potentially affect home air
exchange rates and energy efficiency. These factors included, square footage, attic
and basement size, age, number of doors and windows, wall type, house style, and others.
These results were compiled and analyzed using multivariate regression
analysis, resulting in a predictive model to determine air exchange rates from typical
house features. This model is the basis for Greentrofit™.
