A passive solar house requires an average heating power of 8.4 kW in the winter. It stores energy in 10 tonnes (10,000kg) of Glauber Salt, whose heat of fusion is 241 kJ/kg. At the end of a sunny stretch, the Glauber salt is all liquid at its 32 C melting point. If the weather then turns cloudy for a prolonged period, how long the Glauber salt stay at 32 C and thus keep the house confortable?