$1,$ Air source heat pump means what?

$2,$ When the outdoor coil is operating during cold weather why does it freeze?

$3,$ During defrost cycle what actually happens?

$4,$ What is the first balance point?

$5,$ Is there a second balance point, explain?

$6,$ How are heat Pumps sized?

$7,$ Do heat pumps need to have a second source of heat?

$8,$ In the southern part of the USA how does a heat pump Fail?

$9,$ At what outdoor air temperature does a heat pump stop working?

$10,$ Are Air cooled heat pumps the only kind used?