Patent ID: 7575047

Claim:
A heating arrangement for a building built on soil and having a roof, comprising: heat pump means including first conduit means forming a primary circuit for distributing a heated medium, and second conduit means forming a secondary circuit for circulating a heat carrier medium; water container means including a rain water cistern; first heat exchanger means in communication with said water container means, said first heat exchanger means being in communication with said second conduit means for warming up said heat carrier medium cooled in said heat pump means and returning it to said heat pump means, said first heat exchanger means including at least two heat exchanging segments, each segment being provided with a fore-run collector and a return collector, adjacent heat exchanging segments configured to have the heat carrier medium flow in reverse direction, and the fore-run and return collectors of adjacent segments being directly side by side; pump means for pumping water from said water container means to said roof; distributing means for receiving water from said water container means with the aid of said pump means and for distributing said water on said roof to flow over said roof; water recollecting means for recollecting water from said roof and for returning it to said water container means; at least one temperature sensor means for providing a temperature signal to indicate whether a normal operation is possible, and to indicate when risk of icing is present, said temperature sensor means being arranged in at least one of the following places: on said roof, in said water container means, and in said conduit means; control means receiving said temperature signal for controlling said pump means, said control means being programmed so that during normal operation water is fed from said water container means onto said roof, is heated there and is returned to said water container means, and in times where said temperature signal indicates the risk of icing of the water, said pump means are controlled in such a manner that feeding water to the roof is interrupted, and said distribution means are drained off.