Peter,
The "Rossi effect" is controlled in a narrow range by balancing heat removal and heat addition. It will not work reliably without constant heat removal. Therefore, power input related to the proper operation must be included as P-in. Jones From: Peter Gluck Dear Jones, just from curiosity, in what kind of P-in has to be included the pump's power and why? Peter > We presume (hope) that the Swedes will not use a hose connected to plumbing where you get free water pressure, and will use a pump. The pump's power must be included in P-in. A liter/sec pump seems to require one horsepower or about .75 kW.