The chilled water system and fluid used are the most important aspects to an installation. The water/glycol is the vehicle which collects the heat from the process and delivers it to the chiller, and the pipework is the road along which the fluid must travel. If either of these two are deficient in any way, the chiller’s operation will be compromised and the heat transfer capability will be reduced.
If necessary, filters/strainers should be installed and checked regularly, although the best policy is to tackle the source of any contamination. The chilled water system must be flushed, cleaned and sanitised prior to adding a new water/glycol solution. It must also be regularly sampled and tested to ensure there are no underlying or progressive contamination and/or corrosion issues.
For new, or recently cleaned and dosed systems, we recommend a test after three months of operation, including a comprehensive sample analysis. Thereafter, we recommend six monthly routine tests, along with regular visual examinations to check for colour and suspension.
Six monthly analysis is offered free of charge when Glycol has been supplied by Intelicare. Based on these results a quotation will be supplied for any remedial work recommended.
Ethylene-based glycol is the standard process/industrial antifreeze additive and can be used in any application where low toxicity is not a requirement. In terms of efficiency losses, ethylene glycol has the least effect on flow rate, heat transfer capability, and pressure loss. However, ethylene glycol has moderate acute oral toxicity so should not be used in applications where it may encounter potable water, food and/or beverage processing.
CoolFlow IGE has been especially formulated from Ethylene Glycol for use as an Industrial Grade Secondary Refrigerant Antifreeze for use in Process Cooling, Refrigeration and Air Conditioning systems, where toxicity is not an issue.
Propylene-based glycols have low toxicity and are the ideal antifreeze additives for applications in the food and beverage industry and where user contact is a frequent
occurrence. For extra reassurance, make sure it has been tested by the National Sanitary Foundation, which is shown by a NSF mark. This is the assurance that the product is approved by an independent certification organisation that is valued by consumers, manufacturers, retailers, and regulatory agencies worldwide.
Most systems use ordinary mains ‘tap’ water, and while good for human consumption, it can be quite damaging to any chiller and its associated machinery and systems. The relative hardness (and hence the mineral content) varies from region to region, so applying the appropriate inhibitors and biocide is of vital importance. Even microbiological contaminants vary, giving a degree of unpredictability to using town mains water or any other uninhibited water source. Using a ‘pure’ water – distilled, demineralised, de-ionised or RO water – will remove this unpredictability.
However, on its own, pure water can be damaging to heat exchangers due to its tendency to attack certain metals within the chiller and water circuit. It also has very low conductivity which can be a problem with some chillers and systems. We recommend the use of pure water with a suitable (minimum 20%) inhibited glycol mix to give the ultimate system protection. The added glycol will increase the solution’s conductivity to a level which is compatible with both the system materials and any conductivity-based instrumentation. It is important to never use continuously de-ionised/polished water or any pure water without inhibited glycol.
Automotive antifreeze is formulated for engine cooling rather than process or industrial cooling applications, so when it is used for the wrong applications, it can cause problems with flow rates/pressures and reduced heat transfer. Many automotive antifreeze products are not glycol-based and contain other alcohols or glycerine, as well as silicate-based inhibitors, which can coat heat exchangers, attack pump seals, and form a gel, significantly affecting flow rates.
CoolFlow IGE is miscible with water in all proportions and can protect RAC systems down to -50°C depending on concentration. CoolFlow IGE exhibits super-cooling characteristics and mixtures containing in excess of 55% by volume do not freeze solid, alleviating any concern over possible expansion and burst damage.
Plain water is one of the most efficient pumped fluids for absorbing and carrying heat. ,However, when any other chemical is added to it, this ability is affected. Adding glycol will cause an increase in the fluid’s viscosity and density, and decrease its heat transfer and heat carrying properties.
These property changes will not affect the overall functionality of your chilling plant and system as long as they are understood and discussed beforehand as they will result in a slightly reduced cooling capacity, an increased pumping power consumption and an increased fluid temperature difference (or an increased fluid flow).
Optimum Flow: CoolFlow IGE has improved heat transfer characteristics, including lower Dynamic Viscosity and higher Thermal Conductivity. For detailed comparison please refer to the Fluid Performance Chart – available upon request.
Some areas have regulations regarding the use and disposal of particular glycols and antifreeze solutions, concerning things such as ground structure, the water table and drainage. Be sure to consult your local authority to check the local environmental rules. Businesses should also consider using a bio-glycol as an environmentally-friendly solution. Bio-glycols are derived from a sustainable source and are non-toxic, non-flammable, nonhazardous, and biodegradable.
Biodegradable: CoolFlow IGE mixtures are readily biodegradable (90% over ten days) and will not remain in the environment or bio-accumulate.
Different types and brands of glycol shouldn’t be mixed. Most modern glycols contain inhibitors and are dyed for identification. If they are accidentally mixed, incompatibilities can lead to separation and/or reaction, resulting in gel formation which will clog filters, strainers, and pump suctions, as well as causing a deterioration in heat carrying and transfer properties.
Uninhibited glycol and water mixtures are very corrosive, often even more than standard mains water. Modern process and industrial glycols contain inhibitors alongside a pH buffer and biocide to protect against corrosion, scale formation, and rust. For a system to be contamination-free, it needs to be properly flushed, cleaned and sanitised before the addition of a suitable inhibited glycol and water mixture.
Protection: CoolFlow IGE contains synergistic corrosion inhibitors to protect metals commonly found in such systems. It has been tested in accordance with BS5117 and found to meet BS6580 and ASTM D1384 corrosion standards.