Here is a neat posting on one way to keep a greenhouse cool. It discusses systems to keep the greenhouse windows cool on cylindrical shaped greenhouses.
Greenhouses resemble living organisms. They consume sunlight, excrete waste heat, and cope with the force of artificial gravity. A small greenhouse shaped like a sphere can perform these tasks well, but a large greenhouse must have a complex shape and a complex system of mirrors guiding sunlight into its interior. When the diameter of the spherical greenhouse is doubled, its internal area is quadrupled, its mass is increased 8 times, and its cost per square meter of internal surface is doubled. A large greenhouse shaped like a torus, spiral, helix, or band can sustain a great diversity of species and commercial services, but is afflicted by human conflicts and pests.
A slender cylindrical greenhouse has a high ratio of internal horizontal surface to volume. On the other hand, it is unstable unless attached by a bearing to other spinning greenhouses. This instability is caused by the tendency of a freely spinning object to change its axis of rotation until it rotates about the axis having the greatest moment of inertia. A large cylindrical greenhouse fails catastrophically when its bearing malfunctions.
In my opinion, the most practical settlement is a cluster of small greenhouses docked with a stationary hub. The settlement is easy to build while providing lots of diversity, safety, environmental control, and freedom. A family living in a small greenhouse is self-sufficient, so it can sail away and join another settlement. Each greenhouse is shaped like a teardrop to reduce the slope leading to the docking port. In addition to providing an air-tight seal, the docking port acts as a journal bearing. Flora and fauna migrate between residential greenhouses through the hub. Seeds and small animals drift in the hub with a wind produced by fluctuation of air pressure in the greenhouses. Agricultural greenhouses are locked to keep pests away.