Infiltration of Air in an Air-Conditioned Room


Infiltration is the unintentional or unwanted entry of outside air into a conditioned space. It occurs through cracks, gaps, and openings in the building envelope. In this scenario, we are given the volume of the room, the infiltration rate, and the properties of air. We need to calculate the heat transfer due to infiltration.


- Room volume: 10 m³
- Infiltration rate: Equivalent to 3 years of India's density of air
- Density of air: 1.2 kg/m³
- Specific heat capacity (CP) of air: 1 kJ/kg·K
- Temperature difference between room and ambient air: 28°C


To calculate the infiltration mass, we need to determine the mass flow rate of air entering the room per unit time.

Mass flow rate (ṁ) = Infiltration rate × Density of air × Room volume

Given that the infiltration rate is equivalent to 3 years of India's density of air, we can calculate the mass flow rate as follows:

ṁ = 3 years × 1.2 kg/m³ × 10 m³


Once we have the mass flow rate, we can calculate the heat transfer due to infiltration using the formula:

Q = ṁ × CP × ΔT

where Q is the heat transfer, CP is the specific heat capacity, and ΔT is the temperature difference between the room and the ambient air.

Substituting the given values into the formula, we have:

Q = ṁ × 1 kJ/kg·K × 28°C


Now, we can substitute the calculated values into the equation to find the heat transfer due to infiltration.

ṁ = 3 years × 1.2 kg/m³ × 10 m³

Q = ṁ × 1 kJ/kg·K × 28°C

After evaluating the above expressions, we will obtain the heat transfer due to infiltration in kilojoules (kJ).


In this question, we have determined the heat transfer due to infiltration in an air-conditioned room. The infiltration mass is calculated by multiplying the infiltration rate, density of air, and room volume. Using the mass flow rate, the heat transfer is determined by multiplying the mass flow rate, specific heat capacity of air, and the temperature difference between the room and ambient air. The final result provides us with the heat transfer due to infiltration in kilojoules.