Your second consideration should be where your heat sinks are located. In most cases, heat sinks are inteded to be completely passive, So the materials should be placed so that they receive abundant direct sunlight during daytime, and are centrally located so that the heat they release at night reaches the furthest stretches of the greenhouse. These needs must be balanced against the plants' sun requirements and the importance of maintaining a safe, efficient work space.
Thermal batteries or heat sinks are passive elements, and they operate according to the laws of thermodynamics without any human interference If you've selected a suitable battery size and material and located it in an ideal location within your greenhouse, you can pretty much set it and forget it - nature takes care of the rest.
