chiller - what do I do now?

[RabMaxwell]

I think the aquarium heater would be fine. With the thermo box insulation you won't need much heating even in winter.

[Scooby]

Heating pads - good price! Would they wrap round the plastic FV or just sit underneath? I have one old Boots aquarium-style heater, which I could use for a third setup...

The heat pads are less than 1mm thick and and the 20w pad wraps about halfway round the circumference of my 30cm dia fermenter. I checked with Neil regarding bending them and he said they were quite tough and it would be ok as long as it the bend wasn't to acute and that constant bending may cause damage. They are tough and seem ideal for the use.

I'm not sure if 20w will be enough heat in the dead of winter but I'll wait and see and add another one if needed.

A heating mat would not be much good as the box is insulated and I am wondering whether the aquarium heater will be enough in a batch that size.

I've used an Immersion heater before and iirc the wattage required is roughly equal to the vol so a 50/75 watt would be required, as Rab said with the insulation the lower end will prob be ok

Do you guys suffer from the chiller turning on which drops the temperature enough for the heater to come on? I have been getting this but I have since just turned the heater off in this weather.

I have a set temp of 20c and the heating and cooling hysteresis set to 0.2c the max/min in my garage this last few day has been 16-23c so far the overshoot has been 0.1c each way so haven't experience that problem. The TC-10 not only has heating and cooling hysteresis but a 'dead zone' setting so it's easy to overcome if it does happen.

[RabMaxwell]

I use a light bulb to heat my fermenter in winter inside my very well insulated fermentation box.The light only turns on now & again towards the end of the fermentation even in frosty weather.I wouldn't rely on the aquarium heaters thermostat i would have it controlled bt a TC-10 or ATC or similar. I have my TC-10 set at HSC-02 /HSH-04 & don't get any problems:D

[Scooby]

That's right Rab, I turned mine up to max and controlled with an ATC 300

Also the vol/watt I mentioned above is for uninsulated fish tanks.

I have a 25w greenhouse heater in my beer fridge for winter heating and that only comes on for short periods and very occasionally. With good insulation the wattage can be very low. I think the gentle heat from the 20w vivarium pad wrapped round the fermenter with good insulation over that will be ok

[edit1now]

Mine have been varying by +/- 1 degree: half over sometimes, half under. If I try the aquarium heater route I'll certainly use the TC-10, with the heater's own thermostat cranked up to max.

I'm going to try multiple fermenters in series off the one chiller, once I get more insulating jackets and plumbed lids sorted-out. I think that if I have two examples of similar beers, or even (eventually) a 50l batch split into two fermenters, if I monitor one and heat/chill both, it ought to work. I can measure the temperature in the un-monitored fermenter to check.

[Digby Swift]

Sorry I meant to say its controlled by a tc-10, I think that I will have to mess around with the dead zone setting as I just set that to 0 and haven't bothered to check about it.

[Scooby]

I haven't resorted to the dead zone and also have it set to 0

In the 3 days of fermentation when I have looked the temp has been 19.9c, 20 c or 20.1 the chiller has been working twice and heating once, the TC-10 calls for heat at 19.8c and switches off at 20c, it calls for cooling at 20.2 and switches off at 20c. I think the key is insulation, I have only cobbled together a fiber glass wrap but it is 80mm thick and the fermenter is 8mm thick.

[Digby Swift]

I have used camping mat insulation. Not sure how effective it is. The trouble is that the cooling over shoots and gets too low around the probe and then the heater kicks in. This didn't happen on the previous 2 brews so it could be that the probe is in a rubbish position.

[Scooby]

Ah! maybe I should have said insulation and probe position are the key

The temp in various positions in the fv and the detrimental effect on the process is something Chris has flagged up (controlling the temp of chilling water). I notice e1n uses some of the silicon sheet to space the probe away from the cooling element. I designed my element with a dog leg to crank it away from the probe. I think you may be right

[Digby Swift]

Yes it is something I have considered as I think you need a bit of time for the outer edge, and warmer beer, to diffuse throughout to equalise the temperature. Perhaps I need to set a longer delay to get this to happen. I currently have it on 5 minutes. I think that I need to think of a solution for the probe position though, something like edit has done.