摘要 |
A pump or blower device particularly for heating and air conditioning systems is provided with a plurality of inlet ports and a plurality of outlet ports. Axially displaceable impeller means are moved to connect any one inlet port selectively with a first outlet port or with a second different outlet port or with a plurality of outlet ports simultaneously. The device is of great advantage in controlling the circulation of heating or cooling fluids between a primary circuit and secondary circuits that branch out to provided heating or cooling in selected separate areas of a building or to a plurality of buildings serviced by the primary circuit. The present device decreases the number of pumps and mixing valves in the systems and results in decreasing installation and operating costs. |