Setting up a solar thermal space heating system is only one side of the renewable energy heating coin. The other side is actually delivering the heat the installation generates to your home. Assuming you've chosen an appropriate system for your needs, you have captured the sun's energy and either stored it or have it ready to be dumped straight into the building. What next?
There are two types of heating to consider here: radiant and convective. You will also need to decide whether your existing, grid-tied heating installation is (or can be) integrated with the solar thermal system or not.
Convective heat
Convective heat is the heat which is transported by warm air. When you open an oven, for example, the hot air inside rises out into the kitchen, creating a current that pushes colder air down as the hot air heads towards the ceiling.
Convective systems are the more traditional option but are not very efficient because they heat buildings from the wrong end. All the hot air they generate rises to the ceiling, so they have to heat all the air in the room before the temperature becomes stable.
Convection heaters include fan blowers, oil heaters, and most traditional radiators (despite being called radiators).
Radiant heat
Radiant heat is heat which passes from the delivery mechanism to you or other objects, through the surrounding air. If you place your hand near a wood stove or in front of an oven (without touching them), you will experience radiant heat. In solar thermal systems, radiant heat is usually delivered by a warm panel or floor space.
Radiant systems are generally a lot more efficient than convective systems because they heat the floor instead of slowly filling the living space from the ceiling downwards. They pass heat directly to the objects in the room, rather than circulating warm air to those objects, thus reaching a stable temperature much quicker and maintaining it better.
Radiation heaters include halogen-based heaters, radiant floor tiles and other modern options.