Calculate the rate of infiltration heat loss of a room with a 42 m² floor area and 4 m high ceilings. Use an inside temperature of 21°C and an outside ambient temperature of -15°C. Assume the heat capacity of air is 0.35 W/m³・°C. Base the analysis on the following hourly air exchange rates:
a. Tight, energy efficient construction (ACH = 0.5)
b. Medium construction (ACH = 1.0)
c. Loose construction (ACH = 1.5)