a room of 6000 ft3 is heated by a hydronic (hot water) radiator. Water enters the radiator at a mass flow rate of 10 lb/min and a temperature of 180 F and exits the radiator at 160 F. This room has a net R-value of 2 ft2 F hr/BTU and an area of 500 ft2 of exterior wall. But in addition to the heat loss calculated based on the R-value, someone has left a door ajar and there is an additional loss of warm indoor air to the outdoors at a rate of 2 lb/min, replaced by cold outside air flowing in. Air has a heat capacity of 0.24 BTU/lb-F. With this additional heat loss, what is the indoor temperature at steady-state, if the outdoor air is 20 F? Draw and label a diagram of the room, write a mass balance expression, and solve for indoor temperature.