Coolants are widely used in HVAC cooling systems in data centers. The main purpose of a coolant is to save a system from any catastrophic damage due to heat. It is hence usually circulated around the heat generating system, absorbing and dissipating heat evenly. It may be referred to as ‘antifreeze’ when it is used to keep a system from freezing when operated below 32 degrees Fahrenheit.
What does a Coolant contain?
Choice of a coolant or antifreeze is made based on the use, here are the general choices:
Ethylene glycol is the most popular coolant available in the market today; methanol, ethanol, isopropyl alcohol, and propylene glycol are also common choices.
Also known as methyl alcohol, carbinol, wood alcohol, wood naphtha, and wood spirits. It is a simple alcohol; light, volatile, colourless, flammable, poisonous having a distinctive odour. At room temperature it is a polar solvent, generally used as antifreeze, solvent, fuel, and a denaturant for ethyl alcohol. It is popular for machinery. It may be found in automotive windshield washer fluid, de-icers, and gasoline additives.
Glycerol can be used as antifreeze and is not toxic.
4. Propylene Glycol:
Propylene glycol is the least toxic and marketed as “non-toxic antifreeze”. It is a replacement to ethylene glycol in food-processing systems or in water pipes where incidental ingestion may be possible.
Antifreeze is toxic to all, humans and animals alike. It can cause serious water quality issues! Heavy metals such as lead, cadmium, and chromium are usually found in waste coolant; sometimes it may contain high enough levels to make it a regulated hazardous waste! Waste coolant is not allowed to be disposed into land or discharge it into a sanitary sewer, storm drain, ditch, dry well, or septic system.
Recycling coolant is advantageous because:
1) Its cost-effective
2) It saves resources.
The most important ingredient of a coolant the Ethylene Glycol is produced from natural gas which is a non-renewable resource. Data Centers use a lot of coolant for dissipating server heat. Recycling coolant can reduce management costs and reduce the quantity new materials purchased. Recycling antifreeze on site and reconditioning it with additives costs significantly less compared to the cost of purchasing new antifreeze.
How to Recycle?
Recycling coolant involves two major steps:
1. Removing contaminants like emulsified oils and heavy metals by filtration, distillation, reverse osmosis, or ion exchange.
2. Restoring antifreeze properties with additives. Additives usually contain chemicals that stabilize the acidity of the mixture, inhibit rust and corrosion, reduce water scaling, and slow the breakdown of ethylene glycol.
Where to Recycle?
Depending on the feasibility and the magnitude of recycling necessary waste coolant can be recycled in the following arrangements,
1) On-Site Recycling: Waste coolant is recycled in units purchased by the facility, located on site, and operated by the employees.
2) Mobile Recycling Service: A van or truck equipped with a recycling unit visits the facility and recycles waste antifreeze.
3) Off-Site Recycling: Waste coolant is transported to a specialized recycling company, these services can also resupply the facility with recycled antifreeze.
Since September, 1999, there is no ASTM quality standard for recycled antifreeze. However, several state agencies have issued product specifications for recycled antifreeze. Also, some renowned vehicle manufacturers test and certify coolant recycling equipment or have developed standards for recycled antifreeze. No single national recycled antifreeze standard is available.
Data Centers cannot run without server cooling. The huge amounts of coolant used can be recycled on-site for savings in capital and maintenance. Invest in a coolant recycler for your data center today!
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