• Heat pumps have positioning and refrigerant requirements.Jupiterimages/Photos.com/Getty Images
  
  Heat pumps use a refrigerant to move heat back and forth from the household. While traditional heat pumps are designed to only provide heat, many versions can switch back and forth between heating and cooling, taking the place of air conditioners. Because heat pumps do not require a fuel, they are considerably less costly to run than traditional heating methods. However, heat pumps do have a high upfront cost and several installation requirements that must be met when they are installed.
  
  

Sizing

• Like other heating devices, heat pumps need to be properly sized. Several sizes of heat pumps can move heat at different speeds. The proper size depends on the amount of air in the house and can vary based on other factors. Contractors can use formulas to calculate the proper heat pump size based on its cooling or warming capacity, which is an important requirement to help save energy for the homeowner. Ducts may also need to be changed if they are too small for heat pump airflow.
  
  

Position

• Contractors must also install heat pumps in the proper position. The outdoor portion of the heat pump must be installed in an area free of plants and debris. It must be installed on a solid, level surface and propped on supports above this surface to give water room to drain down (a minimum of 3 inches above grade). Drainage channels must allow excess water to flow easily away from the house.
  
  

Refrigerant

• Installers must also make sure that the refrigerant system is charged or properly filled with the right refrigerant. Different heat pumps are designed to work with various refrigerants at specific pressure levels. Installers should use instruments to pump and carefully measure the amount of refrigerant in the system within several degrees.
  
  

Geothermal Requirements

• Geothermal heat pumps use water lines installed in the ground instead of outdoors. These pumps come with several installation requirements of their own. Homeowners must have access to an underground water source, such as the water table or a lake. The ground must also be free of other pipes or rocks that will get in the water of the geothermal system. Two types of geothermal systems exist: a deep version for when owners have only a narrow space to work with and a shallow version for when contractors cannot dig below several feet.