European Stars and Stripes (Newspaper) - May 08, 1948, Darmstadt, Hesse                                Gold into weekend photographs pump takes heat from Rivers lakes subsoil water to warm Pool for More than 100 years scientists have in pwn Fiat River Lake and subsoil water contained heat. How to extract that Energy which dior Manly flows from a warm body to a colder one stumped the Laboratory men. Recently however ingenious Swiss engineers found the practical solution when they developed the heat pump. The pump Capi _ Alizes on the properties of ammonia which under Ordinary temperatures is easily liquefied and in the process of reconversion to a gaseous state absorbs a relatively Large amount of heat. It is at this stage in the process that the heat Energy is utilized As in the Case of the Plant at Zurich to provide hot water for the swimming Pool. ? when the head pump is used on a Large scale Only 545,000 tons of Coal is needed for every million tons formerly used in grates of centrally heated installations. Nevertheless the one great drawback of heating is the Cost of the electric Power necessary to operate the pump s com Pressor unit. But As one of the Pool engineers Points put the same Plant we use for heating in Winter is. Easily converted to a Cooling unit in the summer."". Zurich Pool maintains water and building temperature at 82 degrees fahrenheit ammonia Gas Pale red fills tubing placed below River surface lower left. Introduced at lower temperature than River water it absorbs heat and passes on to compressor where it is liquefied. In passing through boiler like tank at High temperature heat Energy is transmitted to water circulating through tank from swimming Pool. Leaving tank the ammonia expands in valve returning to original gaseous state. This conversion unit is used also in a few Zurich office buildings. Large Ripe beneath sidewalk Over River Bank is part