Heater

Abstract

A heater for a room heating system includes a heating element, a housing having the heating element disposed therein, a thermal distribution fluid inlet into the housing, a thermal distribution fluid outlet from the housing, and at least one safety feature connection. The housing is arranged to contain thermal distribution fluid as the thermal distribution fluid follows a flow path from the thermal distribution fluid inlet to the thermal distribution fluid outlet and over the heating element. The at least one safety feature connection includes a passage through the housing.

1 . A heater for a room heating system, comprising:
 a heating element;   a housing having the heating element disposed therein;   a thermal distribution fluid inlet into the housing;   a thermal distribution fluid outlet from the housing;   the housing being arranged and configured to contain thermal distribution fluid as the thermal distribution fluid follows a flow path from the thermal distribution fluid inlet to the thermal distribution fluid outlet and over the heating element; and   at least one safety feature connection including a passage through the housing.   
     
     
         2 . The heater of  claim 1 , further comprising
 at least one safety feature of the room heating system connected to the safety feature connection, the safety feature being responsive to the thermal distribution fluid contained by the housing.   
     
     
         3 . The heater of  claim 1 , wherein
 the at least one safety feature connection includes a plurality of the safety feature connections.   
     
     
         4 . The heater of  claim 3 , further comprising
 a plurality of the safety features connected to a respective one of the safety feature connections, the safety features being responsive to the thermal distribution fluid contained by the housing.   
     
     
         5 . The heater of  claim 2 , wherein
 the at least one safety feature includes a system safety valve arranged and configured to open when a predetermined pressure in the thermal distribution fluid has been exceeded in order to release excess pressure in the thermal distribution fluid.   
     
     
         6 . The heater of  claim 1 , wherein
 the at least one safety feature connection includes a thermal distribution fluid outlet connection to an expansion vessel.   
     
     
         7 . The heater of  claim 2 , wherein
 the at least one safety feature includes a gas release valve operable to release gas accumulated in the heater.   
     
     
         8 . The heater of  claim 1 , wherein
 the housing includes opposed ends with a side wall extending longitudinally therebetween and the heating element is mounted to one of the opposed ends and extends toward the other of the opposed ends, and   the at least one safety feature connection includes a passage through the side wall.   
     
     
         9 . The heater of  claim 1 , wherein
 the housing includes opposed ends with a side wall extending longitudinally therebetween and the heating element is mounted to one of the opposed ends and extends toward the other of the opposed ends, and   at least one of the thermal distribution fluid inlet into the housing and the thermal distribution fluid outlet from the housing include a passage through the side wall.   
     
     
         10 . The heater of  claim 7 , wherein
 the housing is arranged and configured to be mounted in a predetermined orientation,   the gas release valve is mounted at a top of the housing when the housing is in the predetermined orientation, the top of the housing being where gas can accumulate during use of the heater, and   the thermal distribution inlet and the thermal distribution outlet are positioned below the gas release valve when the housing is in the predetermined orientation.   
     
     
         11 . The heater of  claim 10 , wherein
 the predetermined orientation is substantially horizontal and the gas valve is mounted to a longitudinal center of the side wall.   
     
     
         12 . An indoor unit including the heater of  claim 1  for a room heating system including a heat pump having an outdoor evaporator, a compressor, a condenser forming a heat exchanger and an expansion device connected by refrigerant piping in a cycle and a thermal distribution medium piping formed to circulate a thermal distribution medium and to flow the medium through the heat exchanger between the refrigerant and the medium, wherein
 the heat exchanger, a portion of the thermal distribution medium piping and the heater form parts of the indoor unit. 
 
     
     
         13 . The indoor unit of  claim 12 , wherein
 the at least one safety feature connection includes a thermal distribution fluid outlet connection to an expansion vessel, with the expansion vessel forming part of the indoor unit, and   the expansion vessel is configured to change a volume of the thermal distribution medium that can be accommodated by the piping in response to volume changes in the thermal distribution medium.   
     
     
         14 . The indoor unit of  claim 12 , wherein
 the heater further includes at least one safety feature of the room heating system connected to the safety feature connection, the safety feature being responsive to the thermal distribution fluid contained by the housing,   the at least one safety feature includes a gas release valve operable to release gas accumulated in the heater,   the housing is arranged and configured to be mounted in a predetermined orientation,   the gas release valve is mounted at a top of the housing when the housing is in the predetermined orientation, the top of the housing being where gas can accumulate during use of the heater,   the thermal distribution inlet and the thermal distribution outlet are positioned below the gas release valve when the housing is in the predetermined orientation, and   the heater is mounted to the indoor unit in the predetermined orientation.   
     
     
         15 . The indoor unit of  claim 12 , wherein
 the heater is mounted at a top part of the indoor unit.   
     
     
         16 . The indoor unit of  claim 12 , wherein
 the indoor unit is mounted with respect to the room heating system such that the heater forms an uppermost component of the room heating system.   
     
     
         17 . The indoor unit of  claim 14 , wherein
 the heater is mounted at a top part of the indoor unit.   
     
     
         18 . The indoor unit of  claim 17 , wherein
 the indoor unit is mounted with respect to the room heating system such that the heater forms an uppermost component of the room heating system.   
     
     
         19 . The indoor unit of  claim 14 , wherein
 the indoor unit is mounted with respect to the room heating system such that the heater forms an uppermost component of the room heating system.