4.3. Typical Equations

Try these first

1. 1.

   Define sensible heat and give the equation used in HVAC.

   Hint

   Think about how temperature change affects heat transfer.

2. 2.

   What does latent heat represent in an air-conditioning context?

   Hint

   Consider how moisture affects cooling.

3. 3.

   What is the equation used to calculate sensible heat?

   • Q = m * c_p * ΔT
   • Q = m * h_fg * Δω
   • Q_total = Q_sensible + Q_latent

   Hint

   Consider what factors influence temperature changes.

4. 4.

   True or False: Latent heat involves a change in phase of a substance.

   • True
   • False

   Hint

   Think about materials changing states.

5. 5.

   A room requires a 7°C increase in temperature. If the mass of air in this room is 1.2 kg and the specific heat capacity is 1.006 kJ/kg·°C, how much energy is needed to reach the desired temperature?

   Hint

   Substitute the values carefully into the sensible heat equation.

6. 6.

   Consider two air streams, the first having a mass flow rate of 0.5 kg/s at a temperature of 22°C and the second 0.8 kg/s at 28°C. Calculate the resultant temperature of the mixed air stream using the mixing equation.

   Hint

   Ensure you apply the mixing equation accurately.