Gregory in Grand Pre, Nova Scotia has a hot sun room while the rest of the house is relying on the furnace. How can he use the heat from the sun room in the rest of the house?
You have to move the hot air around.
You can buy "through the wall" fans that are actually made for moving heat from a wood stove to the adjoining room. This one was made by Marley, from Bennettsville, SC.
You could use any exhaust fan to draw air from the hot room and dump it into the coldest part of the house, probably the basement floor.
If you have a forced air heating system, you could install a return air duct high up in the hot room and let your furnace ducting take care of distributing it around the house.