Chillers - Marine
Aquarium chillers have now become readily available and affordable for hobbyists to own, they are made to maintain a set temperature even in the hottest of summers (usually 25-26°C).
Some of the better quality units like Teco now have built in heater for better control of the temperature during colder months.
They work by water entering a heat exchanger, connected to a temperature controller where it flows through a series of titanium coils filled with a refrigerant.
Once the Heat exchanger increases temperature the heated refrigerant is then compressed from a liquid into gas that enters the condenser.
To cool the gas a fan is blown into the condenser to reduce the temperature that pumps back into the heat exchanger, as a result you can see as much as 10°C drop in water temperature!
Their efficiency can also be affected by the flow rate of water passing through them, there will be ideal flow rates suggested by the manufacturer of the chiller you purchase so you need to get a pump to suit that model.
Chillers need adequate ventilation so they can work efficiently, and it's a good idea to try and vent their hot exhaust air away from the aquarium as it's counter productive.
Regular maintenance of the chiller should be to keep the air intake filter clean and once a year do a white vinegar/water (1:4 ratio) flush out to remove any trapped debris from inside the small network of titanium tubes within the chiller.
Information provided by:
MARINE AQUARIUM FANATICS AUSTRALIA