Measurement of infiltration rates from daily cycle of ambient CO2

We propose a new approach for measuring air infiltration rates in buildings. The method belongs to the class of tracer gas techniques but, unlike conventional CO2 based methods that assume the outdoor ambient CO2 concentration is constant, the proposed method recognizes that photosynthesis and respiration cycle of plants and processes associated with fuel combustion produce daily, quasi-periodic, variations in the ambient CO2 concentrations.