A new method of reducing the relative humidity (RH) in greenhouses and at the same time reduce energy requirements is the result of operating a LHC system (Latent Heat Converter) also called AGAM units. Using this system, the night-time RH has been reduced to 88% with a mean night temperature of 16.5°C in comparison to 95% and 11.5°C using continuous ventilation without heating. The LHC system will help to reduce the incidence of Botrytis and other diseases that require high humidity, especially in Rose production and the like, and should also help to increase subsequent vase life. An increase of 5°C over the outdoor temperature is also a substantial donation to energy saving. Two heat exchange units (A) and (B) are required. When humid greenhouse air makes contact with the salt water flowing downwards in heat exchanger (A), vapour is condensed on the saltwater. The ‘sensible heat’ of the condensation heats the saltwater which in turn heats the air which is introduced with a lower RH back into the greenhouse. The warm saltwater that accumulates in the reservoir of heat exchanger (A) is pumped to the top of heat exchanger (B) and flows in a downward direction. In doing so the warm saltwater now exchanges heat with cooler outdoor air, the temperature of the outdoor air increases and is also introduced into the greenhouse. The seawater that is now cooler accumulates in the reservoir of heat exchanger (B) and is pumped to the top of heat exchanger (A) to restart the cycle. The diluted saltwater is concentrated in an evaporator heated with hot water from the greenhouse general boiler. Heat from the saltwater evaporator is also introduced into the greenhouse. "FlowerTech" www.Hortiworld.nl Gad Assaf (Agam Energy Systems) E-mail: agamga@netvision.net.il or Naftaly Zieslin (Faculty of Agricultural Environmental and Food Science, University of Jerusalem). E-mail: zieslin@hotmail.com