Definition
A monoblock heat pump is an air-to-water heat pump whose entire refrigerant circuit is sealed inside a single outdoor unit, so only water pipes enter the building. It needs no refrigerant work on site and is the standard format for propane (R290) units, since no flammable refrigerant is brought indoors. Split heat pumps, by contrast, place the condenser indoors and connect the two parts with refrigerant lines.