Basing your investment decision on the sole cost of the equipment or per-liter cost of the cleaning agent is a guaranteed recipe for distorted conclusion. To access the true economic costs of cleaning, you must look at both the acquisition costs and the ongoing costs.
Acquisition costs entail the price of the machine, installation, and retrofits. Operating costs include consumable solvents or detergents/additives, utility bills for electricity/water, process control and bath maintenance, floor space, waste disposal charges, not to mention labor costs in terms of hours and efforts in operation and process monitoring.
By taking into account all the cost parameters, a total cost-per-part cleaned can be devised, which is a much more meaningful and robust indicator of the cost efficiency of your parts cleaning system.
|Aqueous cleaning||Solvent cleaning|
|Initial capital expenditure for machine and cleaning agents||Often lower for equipment set-up and cleaning agents (To enhance cleaning performance and machine efficiency, the addition of ultrasonics, evaporators for water, treatment plants for wastes etc can increase initial investment accordingly).||Often higher for standard solvent machine technology and initial first fill chemicals.|
|Water consumption||Buying and pre-treatment of water, plus disposal of wastewater..||Zero water consumption.|
|Energy consumption||Higher due to increased temperature for optimal cleaning, in addition to extra energy for drying cleaned parts.||Lower (no need for additional heat during vacuum drying normally).|
|Cleaner replacement||More frequent replenishment and bath exchanges as aqueous cleaners get consumed in the process.||Very low solvent replacement volumes, and many fewer solvent bath exchanges, due to continuous solvent recycling via in-built distillation.|
|Process control and bath maintenance costs||Higher due to the need to constantly monitor and adjust the concentration of the chemicals (e.g. builder and surfactants) to secure a stable process. Potential bioburden issues add another layer of process control and necessitate the use of biocides.||Lower as no additional chemicals (beside stabilizers when necessary) are required, so the chemistry in the vapor degreaser remains consistent and requires little attention to ensure a constant cleaning performance.|
|Floor space costs||Higher due to multi-station horizontal machine set up and several cleaning/rinsing bathes||Lower due to vertical machine set-up and vapor degreasing last cleaning step|
|Disposal costs||Amount of oils remove plus the contaminated water from the cleaning and the rinsing tanks||Amount of oils removed plus up to 1-25% of used solvent (depending on the solvent in use)|