The latent heat gain may occur due to any one or all of the following sources:
1. The heat gain due to condensation of moisture from occupants.
2. The heat gain due to moisture in the outside air entering by infiltration.
3. The heat flowing into the building by conduction through exterior walls, floors, ceilings, doors and windows due to the temperature difference on their sides.
4. The heat gain due to moisture passing directly into the conditioned space through permeable walls or partitions from the outside or from adjoining regions where the water vapour pressure is higher.
Q. Which of the above statements are valid?