1268 Heat pump principles
1269 Heat pump evaporator coil - grabbing heat from the outside air
1270 Heat pump condenser coil - giving off warm air to the inside
1271 Heat pump schematic - summer mode
1272 Co-efficient of performance (COP & balance point) |  1273 Balance point
1274 All-electric heat pump system
1275 Water source heat pump - open loop system (well-based)
1276 Ground source heat pump - horizontal closed loop |
