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The various hydroponic media available, such as expanded clay and coconut husk, contain more air space than more traditional potting mixes, delivering increased oxygen to the roots, which is important in epiphytic plants such as orchids and bromeliads, whose roots are exposed to the air in nature. Additional advantages of passive hydroponics ...
Hydronics (from Ancient Greek hydro- 'water') is the use of liquid water or gaseous water (steam) or a water solution (usually glycol with water) as a heat-transfer medium in heating and cooling systems. [1][2] The name differentiates such systems from oil and refrigerant systems. Historically, in large-scale commercial buildings such as high ...
Rich development of surface roots. The Kratky Method is a specialized passive hydroponic technique which involves plants suspended in net pots above a non-circulating water and nutrient reservoir. The various hydroponic media available contain more air space than more traditional potting mixes, delivering increased oxygen to the roots.
Ground-coupled heat exchanger. A qanat and windcatcher used as an earth duct, for both earth coupling and evaporative cooling. No fan is needed; the suction in the lee of the windtower draws the air up and out. A ground-coupled heat exchanger is an underground heat exchanger that can capture heat from and/or dissipate heat to the ground.
Passive cooling covers all natural processes and techniques of heat dissipation and modulation without the use of energy. [1] Some authors consider that minor and simple mechanical systems (e.g. pumps and economizers) can be integrated in passive cooling techniques, as long they are used to enhance the effectiveness of the natural cooling process. [7]
Ground-source heat pumps (GSHPs) – or geothermal heat pumps (GHP), as they are commonly termed in North America – are among the most energy-efficient technologies for providing HVAC and water heating, using far less energy than can be achieved by burning a fuel in a boiler/furnace or by use of resistive electric heaters.
Deep water culture has also been used by hobby growers. Net pots, plastic pots with netting to allow roots to grow through their surface, are filled with a hydroponic medium such as Hydroton or Rockwool to hold the base of the plant. In some cases net pots are not needed. For oxygenation of the hydroponic solution, an airstone is added.
The energy efficiency ratio (EER) of a particular cooling device is the ratio of output cooling energy (in BTUs) to input electrical energy (in watt-hours) at a given operating point. EER is generally calculated using a 95 °F (35 °C) outside temperature and an inside (actually return-air) temperature of 80 °F (27 °C) and 50% relative humidity.