Air source heat pump questions

• What is an air source heat pump?
• How does a heat pump work?
• How efficient are air source heat pumps?
• How do air source heat pumps work?
• How is the efficiency of an air source heat pump measured?
• Is there any government funding available for air source heat pumps?
• What warranty is available?
• What planning requirements should be considered?
• Will heat pumps work on the coldest winter day?
• What benefits do air to water heat pumps offer over ground source?
• In which type of properties can heat pumps be installed?
• Can heat pumps heat swimming pools?
• What maintenance does a Greensource air to water heat pump require?
• What maintenance does a Greensource air to air heat pump require?