Trane® Thermafit™ MWS water-source, multi-pipe (six-pipe) units feature three independent water circuits to satisfy the year-round requirements for heating and cooling in a building. This eliminates the need for duplicate equipment, which significantly reduces floor space requirements, and minimizes the amount of glycol used.
What makes a multi-pipe unit unique?
While a typical cooling-only chiller or heat pump includes one heat exchanger (the evaporator) for heat absorption and a second heat exchanger (condenser) for heat rejection, the Thermafit™ MWS unit includes a third heat exchanger, which can be used for either heat absorption or heat rejection. This third “source/sink” heat exchanger is connected to a geothermal loop or other type of heat extraction/absorption loop, and a series of two-way valves direct refrigerant to the three heat exchangers depending on the mode of operation dictated by the unit controller.
- Cooling mode: Similar to a typical cooling-only water chiller, the evaporator absorbs heat from the chilled-water loop, producing cold water for cooling the building; while the source/sink heat exchanger rejects heat, to a geothermal loop for example. The condenser is inactive during this mode.
- Heating mode: Similar to a heat pump, the condenser rejects heat to the hot-water loop, producing hot water for heating the building; while the source/sink heat exchanger absorbs heat, from a geothermal loop for example. The evaporator is inactive during this mode.
- Simultaneous cooling and heating mode (heat recovery): The evaporator absorbs heat from the chilled-water loop, producing cold water, while the condenser rejects heat to the hot-water loop, producing hot water. The source/sink heat exchanger is inactive during this mode.