Temperature control

[Belto]

Currently I use a heat mat for fermentation but I feel this is so hit and miss due to the local ambient temperatures.
Summer winter etc, I brew in my garage.

Without resorting to fermenting in a heated fridge, box or cupboard etc. what other methods of accurate temperature control are available.

I have considered using a floating thermostat as used in home aquariums.

What temperature range do they have?

Do these have a variable temperature control?

What would be the disadvantages

I would be interested in other methods being used

[Bobba]

I've got an electrim immersion heater. It's got a built in thermostat and heater and I've found it to be pretty good once you turn it down a bit from the factory setting.

[Scooby]

As mentioned you could use an immersion heater, some aquarium ones go down to 18c but the thermostats are not particularly accurate, you could control one with a TC-10, ATC800 or ETC-200B which are more accurate.

I use a 20w Heatmat round my fermenter and it works well, I may need to add another one in the winter but so far its worked well.

Another option is a brewbelt, not used one but works the same as the heatmat. All can be controlled by the thermostats mentioned.

[brewjohn]

I sit my FV on a Richie 40W heating pad and wrap it around with horticulture fleece. I knocked together a simple triac control circuit for the heat pad with a thermistor sensing the beer temp. It seems to work quite well in an unheated brick garage in winter. I put the thermistor in a length of heat shrink sleeving and turned up the end and shrunk it with the hair dryer and it sits in the beer ( after sterilising first !)