2.3.2 Design considerations When designing a passive solar system particularly for natural heating, the following factors must be put into consideration in order to obtain maximum heat. i. The windows of the passive solar poultry brooder must face true south ii. A portion of the south side of poultry brooder must have an unobstructed view of the sun. iii. Properly sized roof over hangs must be used in order to provide shade to vertical south windows during summer months 2.3.3 Sizing of the brooder For sizing of the brooder it is important to know the number of chicks and type of species. In addition, there are some requirements needed. i. Feeding space ii. Watering space for chicks The brooder height must allow for the birds to stand erect (Smith, 2009). The young chicks are small when they hatch but grow quite rapidly and so in sizing the interior space, care must be taken in order to cater for the birds when they grow. This can be achieved by partitioning the interior space of the brooder in that the partitioned area increases as the birds grow.…show more content… 2.4.1 Thermal properties of the materials a) Specific Heat Specific heat is the quantity of heat that is gained or lost by a unit mass of product to accomplish a unit change in temperature, without a change in state: (2.1) Where Q is heat gained or lost (kJ), m is mass (kg), ΔT is temperature change in the material (°C), and Cp is specific heat