Heater sizing spreadsheet

[BeanAnimal]

Heater questions come up quite a bit and the answers tend to vary depending on who you ask. I have authored a small spreadsheet to help people size their heaters.

Simply plug your total water volume in (not tank size, but the amount of water running in the system) and the spreadsheet will show you what kind of temperature gain different standard size heaters will produce.

You should note that the temp gains are absolute and do not take into consideration cooling from evaporation, convection, or other heat loses.

The idea is to use at least 3 heaters on your system (temp controller or not).

With a temperature controller, the heaters should be sized so that 2 of the 3 heaters are capable of maintaining the system the desired temperature. This allows 1 heater to fail and the otehr two to keep up.

Wihtout a temperature controller, the heaters should be sized so that no single heater can cuase the system to overheat in 24 hours (or your choice of times). This means if one of the heaters sticks on, the tank will not be driven into immediate crisis.

Maybe one day I will add a calc for heat loss to the room and evaporation.... maybe.

A lot of small heaters is always better than a big heater.

The standard disclaimers apply.... check the math yourself, I have done this just for fun and can not be responsible for errors or your actions.

Cross posted in DIY as well

temp spreadsheet

Enjoy