Some San Diego heating heat pumps do not require ducts. They are simply fixed to the wall and operate from there. They are usually energy efficient, very compact and most of the times provide sanitary hot water to homes. It is important to note that heat pumps suck in thermal air and convert it to either cool air or warm air depending on the inside conditions of the house. There are heat pumps that use hydronic technology. This is where they capture the outside heat either from a water source or the ground. They are very quiet and use less power than other models making them ideal for people who want to save on electricity.