Components of the load

1. Heat leakage through the fabric due to the heat from warmer area.
2. Heat radiation through transparent surfaces - as a rule, but sometimes other means (heat radiation from the process, such as a stove).
3. Heat gain by forced or natural convection - air infiltration and fresh air supply - of sensible and latent heat.
4. Internal heat sources - lights, people, cars, etc. - of sensible and latent heat.