HHO cells are used in the aftermarket industry as an accessory for an internal combustion engine to reduce fuel consumption. This system can be considered, and actually is a hybrid system, where hydroxy gas is produced to help the combustion process become more efficient.
Design Layout for HHO Cells There are two main designs known as the wet cell and the dry cell system. The final output is the same where hydroxy gas is produced out of the electrolyte solution. Both designs work well and have their own advantages and disadvantages. Good designs should produce a good amount of hydroxy gas per minute with minimum amperage (current withdrawal from vehicle's charging system).
Wet HHO Cell Design The wet cell design consists of the electrodes immersed in the electrolyte solution and has the upper end of the electrodes used as terminals for the positive and negative polarities. The electrolyte solution is constantly in touch with the plates even when the system isn't being used, as the HHO cell is constructed inside the reservoir (tank). The whole electrolyte volume in the reservoir is subjected to a current in the electrolysis process, which often leads to more current withdrawal. Different specific designs in the electrode plates can help reduce the amount of current being used per cycle, which also reduces wasted energy in the form of heat. It is easier to construct and is also easier when cleaning the cell for preventive maintenance. The downside of this type of design is that it is bulky and can be quite a challenge to install in modern engine bays - where space is very limited.
Dry HHO Cell Design The dry cell design is better for saving precious space as they are very slim by nature. The electrolyte solution does not reside in the cell itself, unlike the wet design. The electrolyte is stored in a separate reservoir and is fed to the cells by gravity in most designs. Some designs might use an external pump to help feed the electrolyte in to the enclosed cell. Each dry cell is sealed by a gasket or o-ring so that the electrolyte will only stay in a confined "closed chamber." This results in less current being drawn by the system when producing HHO gas, as only that specific volume of electrolyte is being subjected to the current, as opposed to the wet cell design. Another benefit is that the positive electrodes are subjected to less oxidization as only a small amount of electrolyte solution resides in each closed chamber. The downside of such a design is that gaskets or o-rings do need periodic replacements as they will eventually wear out. This type of maintenance needs the whole unit to be stripped down to pieces for such a procedure. The same type of dismantling is needed to clean and inspect the plates of each chamber. Luckily on good designs, this type of maintenance is usually less periodic when compared to wet cell maintenance.
The Installation Installing a HHO cells system (hydrogen generator) on any vehicle should not realistically void the vehicle's warranty because the engine is not opened up and modified internally. The whole system taps into the intake manifold ducting, through a heat-resistant pipe. The HHO cells unit are installed somewhere in the engine bay area, outside the engine and can be clamped steadily into position by various methods, including heavy-duty cable-ties, if the vehicle's owner decides that there should be no drilling on the vehicle's body.
If in doubt the system can be easily removed prior to a vehicle's service under warranty or for any warranty claims.
If you would like to know more in-depth about HHO cells, including more details about their advantages and disadvantages, you can check out the article on HHO cells, which also includes diagrams for better explanation and safety requirements needed for any installation.
More resources can be found on the subject of Alternative Fuel Energy for vehicles at: http://www.alternativefuelenergy.net/
If the word keeps on spreading as it currently is on Alternative Fuel Energy Sources for I.C.E. vehicles, and more installations are done on normal fossil fuel engines, politicians will have no choice but to accept such devices as environmental-friendly devices. This incentive will probably be enough for full scale production of these devices which will become even cheaper, once they are mass-produced.