While the svelte, digital NeoTherm heater gets all the attention for its looks, the Cobalt Aquatics Accu-Therm heater is one heater you should pay attention to with features that set it also apart from the pack. Heater failure is an issue too many hobbyists have encountered and the Accu-Therm has some design elements to make it affordable, durable and reliable.
Based on a ceramic core instead of a metallic heating element, the heat distribution of the Accu-Therm is more gradual and even around the entire element helping to prevent rapid heating and cooling or creating hot spots that can damage the heater or tank occupants. Sure they are made of glass but the shatter-resistant borosilicate glass helps ensure even heating and cooling while adding heat and shock resistance.
The electronics and thermostat are the more impressive part of the heater and for those of you electronically challenged they do some cool things to help prevent the stuff inside from arcing and causing your heater to stay on and cook everything in your tank, for those of you that are a bit more geeky about things — read on.
First off, most heaters use a bi-metal thermostat with two dissimilar metals that react differently at different temps. As they cool, one stretches or curls towards an electrical contact. Once the connection is made the switch is turned ‘on,’ current flows and the heater pumps out heat. As it reaches a certain higher temperature, the other metal starts to curl or stretch pulling the metal off the electrical contact closing the switch. A downside of this type of thermostat is that as the metals stretch and move with the temperature, they don’t always do it smoothly and the metals flutter around the contact that can cause arcing that essentially welds the contact switch open.
Cobalt has added a few things under the hood to help prevent this. Cobalt added neodynium magnets to the bi-metal thermostat in the Accu-Therm. As the metals react to temperature, the magnets add a little magnetic push/pull to the process to help eliminate flutter and get as clean of an open or closed circuit as possible to prevent arcing. Next they use a TRIAC (Triode for Alternating Current) to control the current flowing through the heater and step down the electrical flow going through the connection. Imagine the current is like water. Trying to fill a glass with a one inch hose at full blast — not too easy right? Now imagine filling up that same glass with some airline tubing, much easier more controlled and less chance of getting water all over the place or blasting the glass off the table.
These AccuTherm heaters are pretty accurate too for analog heaters like this. Cobalt rates the Accu-Therm to be accurate ±0.2°F and have a temperature range of 66-90°F. There are eight sizes ranging from 25W to 300W that retail for around $25.99 to $33.99.