The solar components of a warm air system include; collector, blower, flexible ductwork control system and vents.
The blower is sized acording to the number of collectors and total length of the ductwork. Larger systems with four or more collectors may have more than one blower.
The flexible ductwork is used because it is insulated to keep from losing the heat while air is traveling into the conditioned space.
The control system may be a "temperature differential controller" which uses sensors to compare inside temperature and collector temperature. When the collector temperature is warmer than the inside temperature the blower is turned on to move the heat. Warm air systems sometimes use "bi-metallic" snap switches inside the collector to control the blower.
Vents are needed to attach the flexible duct. One vent is located near a floor to pull cooler inside air to the collectors. One vent is located near the ceiling to push solar heated air into the conditioned space.