The scientific term HHO stands for oxyhydrogen, a mixture of hydrogen and oxygen with a concentration ratio of two hydrogen parts and one oxygen part. Oxyhydrogen is also used in welding torches but has other uses in a vehicle’s engine. HHO in car systems are oxyhydrogen gas generators using water and a catalyst (known as the electrolyte solution) together with an electrical current to produce this gas.
Oxyhydrogen is burnt together with the engine’s primary fuel (gasoline or diesel) and helps the primary fuel fully combust, gaining more energy for the same amount of fuel being used by the engine. This additional (gained) power is more than the engine load needs to operate optimally, so the engine’s primary fuel can be weakened, while the engine gives out the same torque for that particular load.
When the oxyhydrogen (also known as hydroxy gas) burns it reverts back to its original formation before electrolysis took place, meaning it becomes steam vapor, which are fine water droplets.
Different Types of HHO in Car Systems
There are mainly two types of HHO in car systems, comprising of the wet HHO cell and the dry HHO cell configurations. These systems both produce the resultant hydroxy gas, but differ in their technical design. Originally the experimental electrolysis process took place under the wet HHO cell design to produce hydrogen in the labs. The wet cell configuration is still basically the same.
When experimenters started using this configuration as a fuel saving device, the word soon spread out and many D.I.Y. technical persons started trying to improve on the design by using different materials, configuration layouts and different catalysts. The wet cell design has improved significantly over the years and has also become more reliable. Through continuous research and development, certain enthusiastic designers came up with a whole new idea, to reduce the maintenance time associated with the wet cell design. Luckily the latest design also became much more compact, which was a great advantage with cramped modern engine bays. This became known as the dry HHO cell design.
Wet HHO Cell vs Dry HHO Cell
We have tested many different designs currently on the market and even ended up creating a HHO product reviews page for these D.I.Y. HHO technical guides. We have found out that in general both designs have their own advantages and disadvantages.
Wet Cell Design Advantages:
- Easier to clean up periodically as a preventive maintenance procedure
- Easier and faster to change the corroded anode plates
- Does not have many seals which will eventually deteriorate or harden
- Cheaper to build compared to most dry cell designs
- No additional external pumps are needed for the electrolyte
Wet Cell Design Disadvantages:
- Bulky in design which might be a problem to install on modern engine bays
- Frequent anode corrosion due to oxidation which leads to more cleaning
- Anode plates will need to be replaced more frequently because of excessive corrosion
- Wet cell design generates more heat in the electrolyte solution
- More current is needed compared to the dry HHO cell design
- Electrolyte design needs more frequent flushing with fresh clean electrolyte
Dry Cell Design Advantages:
- Very compact in nature in both width and thickness
- Needs less current to operate consistently
- Heat build-up in the HHO generator is nearly non-existent
- Electrolyte remains cleaner for longer intervals
- Anode plates corrode much less
- Terminals do not corrode as they are isolated from the electrolyte
- Less periodic maintenance is usually needed
Dry Cell Design Disadvantages:
- More costly to produce or build one up as a D.I.Y project
- More accuracy is needed to build the design
- Each cell is separated by a seal which will ultimately harden and start leaking
- Preventive maintenance procedures require to strip the whole HHO generator to pieces
- On most designs an external pump is needed for the electrolyte
As you have seen from above both wet and dry HHO in car designs have their pros and cons. Depending on the space available in your engine bay is a major factor to consider, before attempting such an installation. Most modern vehicles which all seem to have very little space available will probably need the dry cell design for mainly two reasons which are less space is required and less maintenance frequency. This allows the installation to be placed in even the tightest and most difficult areas for access, if that is your only option available. A common option is to install the dry cell HHO generator in front of the radiator, just behind the bumper or behind the front fender, in the wheel well area which is covered by a plastic fender liner from the factory.