What's Missing from Your Recycled Antifreeze

More maintenance shops are using recycled antifreeze. It’s less expensive than virgin antifreeze, it saves a non-renewable resource (ethylene glycol is a natural gas derivative), and it reduces the amount of hazardous waste a shop generates. Formulated properly, it should deliver the performance you expect.

And that’s the key phrase: formulated properly.

“In order to produce clean ethylene glycol, the recycling process sifts out contaminants from the coolant but also the additives that protect metals and rubber in the HVAC system,” says Frank Burrow, manager of warranty and product support at Red Dot Corp., a leader in climate control systems for heavy-duty vehicles and off-highway equipment.

Some shops ask the recycler to replenish the additives before delivery, which a reputable recycler will do in a consistent, temperature-controlled environment. Other shops will buy premixed additives separately and stir them into the ethylene glycol themselves.

Unless the additives are blended at the right temperature, Burrow says, they won’t stay in suspension and the antifreeze drawn from the drum may lack the additives necessary to protect seals, filters, and other components.

“It’s like adding sugar to cold coffee,” he explains. “You don’t taste the sweetness until you’ve reached the bottom of the mug.”

If you buy recycled antifreeze, talk to your supplier about his methods for mixing additive packages. If you mix the additives yourself, double-check to make sure you’re doing it properly, at the right temperature.

It’s great to go green by using recycled coolant. But doing it at the expense of your HVAC components will have you seeing red.