Integrated energy recovery systems

Abstract

An energy efficient laundry facility comprises a space heating system, an air conditioning system, a plurality of clothes washers, a plurality of clothes dryers, a hot water storage tank supplying the washers, a source of cold water and conduit means interconnecting the aforesaid. Dedicated heat recovery units are associated respectively with the dryers and employ high temperature dryer exhaust air to heat water for supply to the storage tank. A controller and temperature sensing means regulate the flow of hot water from the dryers to the storage tank. High temperature water is directed to the top of the storage tank and lower temperature water to an intermediate point in the storage tank. Hot water from the dryers is also directed to the space heating system. Each heat recovery unit comprises a heat exchanger, a blower, a water circulation pump, a water temperature sensor, and a dedicated controller. The controller may also include a dryer exhaust pressure monitor, a pressure controller, and a variable speed blower drive. The heat exchanger is of the counterflow type and each recovery unit has its heat exchanger and blower arranged to provide for right angle air flow resulting in a compact unit for mounting atop a clothes dryer. Hot water may also be drawn from the storage tank for use in either an air or hydronic space heating system.

1 . An energy efficient laundry facility comprising a space heating system, an air conditioning system, a plurality of clothes washers, a plurality of clothes dryers, a hot water storage tank supplying the washers, a source of cold water, a conduit means interconnecting the washers, dryers, storage tank, and cold water supply source, a plurality of dedicated heat recovery units associated respectively with said dryers and including heat exchangers and blowers which employ high temperature dryer exhaust air to heat water for supply to said storage tank, and a plurality of dedicated controller and temperature sensing means associated respectively with said heat recovery units for regulating the flow of hot water from the units to the storage tank. 
     
     
         2 . An energy efficient laundry facility as set forth in  claim 1  wherein each controller for a heat recovery unit directs hot water at a high temperature to the top of the storage tank and hot water at a substantially lower temperature to an intermediate point in the storage tank. 
     
     
         3 . An energy laundry facility as set forth in  claim 1  wherein conduit means are provided for directing hot water from the storage tank to the space heating system. 
     
     
         4 . An energy efficient laundry facility as set forth in  claim 1  wherein each heat recovery unit comprises a housing, a heat exchanger, a blower, a water circulation pump and a dedicated controller. 
     
     
         5 . An energy efficient laundry facility as set forth in  claim 1  wherein each heat recovery unit includes an exit water temperature sensor and a variable speed pump regulated by said controller. 
     
     
         6 . An energy efficient laundry facility as set forth in  claim 5  wherein each temperature controller regulates pump speed to maintain a pre-selected water discharge temperature. 
     
     
         7 . An energy efficient laundry facility as set forth in  claim 6  wherein each controller includes a dryer exhaust pressure monitor, a pressure controller and a variable speed blower drive. 
     
     
         8 . An energy efficient laundry facility as set forth in  claim 7  wherein each pressure controller varies the blower speed to maintain a desired dryer exhaust pressure. 
     
     
         9 . An energy efficient laundry facility as set forth in  claim 8  wherein each controller indicates when the blower is operating. 
     
     
         10 . An energy efficient laundry facility as set forth in  claim 9  wherein each controller operates the pump only when the blower is operating. 
     
     
         11 . An energy efficient laundry facility as set forth in  claim 10  wherein individual electrically operable shutoff valves are provided respectively for the hot water discharge ports and the warm water discharge ports. 
     
     
         12 . An energy efficient laundry facility as set forth in  claim 1  wherein a replaceable lint filter is disposed in the path of airflow through the unit. 
     
     
         13 . An energy efficient laundry facility as set forth in  claim 1  wherein each heat exchanger is of the counterflow type with the hot air entering the same adjacent the heated water exiting the same thus providing the hottest possible water. 
     
     
         14 . An energy efficient laundry facility as set forth in  claim 13  wherein each heat recovery unit has its heat exchanger and blower arranged to provide for substantially right angle air flow path therebetween resulting in a compact unit well suited to mounting atop a clothes dryer. 
     
     
         15 . An energy efficient laundry facility as set forth in  claim 14  wherein the clothes dryers have exhaust vents on their top surface, and wherein the recovery units have complementary air inlet openings on their lower surfaces for receiving heated air flow from the vents. 
     
     
         16 . An energy efficient laundry facility as set forth in  claim 1  wherein each heat recovery unit has separable heat exchanger sections and air handling sections, the latter including the blower, pump, controller etc. 
     
     
         17 . An energy efficient laundry facility as set forth in  claim 1  wherein a damper is provided for both directing air to the blower and directing air from the heat exchanger to an exhaust port, the damper having both normal and bypass positions. 
     
     
         18 . An energy efficient laundry facility as set forth in  claim 1  wherein each heat exchanger and blower are disposed in a linear configuration for connection with an exhaust header. 
     
     
         19 . An energy efficient laundry facility as set forth in  claim 1  wherein each recovery unit is mounted on top of a dryer and has a condensate collection pan disposed at a bottom portion in engagement with the top wall of the dryer. 
     
     
         20 . An energy efficient laundry facility as set forth in  claim 1  wherein each heat recovery unit includes a thin, flat, heat exchanger and blower arrangement which may be conveniently mounted on a wall behind the dryer, the unit being connected to the dryer discharge vent by conduit means. 
     
     
         21 . An energy efficient laundry facility as set forth in  claim 1  wherein a heat exchanger is provided upstream of a furnace or the like in the space heating system, and wherein conduit means is provided connecting the storage tank to said heat exchanger for preheating air entering the furnace or the like. 
     
     
         22 . An energy efficient laundry facility as set forth in  claim 1  wherein conduit means is provided connecting the storage tank with a hydronic space heating system for supply to base board heaters or the like. 
     
     
         23 . An energy efficient laundry facility as set forth in  claim 1  wherein a water to water heat exchanger is provided in a hydronic space heating system, and wherein conduit means is provided for connecting the storage tank to the heat exchanger. 
     
     
         24 . An energy efficient laundry facility as set forth in  claim 1  wherein a water to refrigerant heat exchanger is provided in the air conditioning system, and wherein conduit means is provided between the cold water source for the laundry and the heat exchanger for a supply of cold water to the heat exchanger and produces a reduction in the high side temperature of the heat exchanger, the cold water thereafter being employed in operation of the washers and dryers.