Q = (m x Cp x ΔT) / (3600 x EER)
Where:
Q = cooling load (Watts)
m = mass flow rate of air (kg/s)
Cp = specific heat of air (J/kg-°C)
ΔT = change in temperature (°C)
EER = energy efficiency ratio of the cooling system
This formula can be used to calculate the cooling load required for a specific space. For example, let's say we have a room with a volume of 100 cubic meters, and we want to maintain a temperature of 25°C. The room is exposed to solar radiation, causing a heat gain of 10,000 watts. The mass flow rate of air in the room is 0.25 kg/s, and the specific heat of air is 1.006 J/kg-°C. The energy efficiency ratio of the cooling system is 3.5.
To calculate the cooling load, we first need to determine the change in temperature by subtracting the desired room temperature from the solar heat gain:
ΔT = 10,000 - (25 x 100 x 0.25 x 1.006) = 7.5 °C
Now, we can plug in the values into the formula:
Q = (0.25 x 1.006 x 7.5) / (3600 x 3.5) = 0.073 kW
This means that the cooling system needs to be able to remove 73 Watts of heat from the room to maintain a temperature of 25°C.
In the air conditioning industry, cooling load calculation is an essential step in the design of air conditioning systems. It helps to ensure that the system is appropriately sized to meet the cooling demands of the space, and that it is energy-efficient. Engineers use this formula along with other calculations to design cooling systems that meet the specific needs of a building or space.