Many homes these days are built with forced air heating systems. These systems consist of a furnace that heats the air, a fan that propels the air, and ducts that carry the air to the home's various rooms. Forced air heating systems work well, but they do require that your walls house some pretty large, thick ducts. What if your walls can't fit such ducts — or what if you don't want to have the home built to accommodate them? Thankfully, there are some other types of heating systems that don't require ducts.
Hot Water Boilers
Hot water boilers are sometimes seen as an old-fashioned type of heating system. They aren't as common as they once were. However, they do still exist, and they actually have a few advantages over forced air heating. They are a good choice for allergy sufferers since they don't propel pollen or pet dander through the air.
A hot water boiler system consists of a big tank that boils the water, a series of pipes that carry that hot water through the home, and radiators in each room. The hot water goes into the radiators, and the radiators pass their heat onto the air and surfaces around them. The pipes that carry the hot water are a lot smaller than ducts, so they are much easier to incorporate into the walls.
Another type of heating system consists of a boiler that holds water, boils it, and gives off steam. There is a series of pipes that trap that steam and carry it into radiators throughout the home. As with a hot water boiler system, the pipes associated with a steam boiler system are small and easy to incorporate into your walls.
Steam boilers are less prone to leaks than water boilers. They may not be quite as efficient, though.
Electric Baseboard Heaters
Another option is to have electrical heaters installed in your home. Often, these will be baseboard heaters, which means they're positioned along the baseboards of your room where the walls meet the floor. Electric baseboard heaters have heating elements that get warm, similar to the burners on an electric stove.
Electric heaters aren't known for being very efficient. However, they are easy to install and they don't require any equipment to be run through your walls, aside from some wiring.
If you don't have space for air ducts, talk to your heating contractor about these other types of heating systems.