How much heat from a lightbulb?

I have an old (I mean old) upright freezer that I've been thinking about using in the basement as a fermentation chest. My basement runs around 55-60 in the winter, so I'm thinking that a light bulb triggered by a Ranco or Johnson controls would probably be enough to keep it fairly steady at 68 or so for ales. Anyone done this?

I'm very wary of space heaters, plus I think it would fluctuate more that way, since the heater would only run a very short time before reaching the set point.

It should work but don't you want to shield the wort from the light? Maybe if you can at least shade it with a piece of sheet metal. Perhaps a heat rock for a lizard tank would be better.

When I was building my walk-in cooler, I left the light on one night... the next morning, the inside of the cooler was so hot I couldn't even breath in there.

Get the smallest (lowest wattage) appliance bulb you can find and stick it in a section of 3" metal dryer flex.

I use a light bulb to keep my unit at a steady temperature, for years. I use a electric thermostat to control the light bulb and temperature. It works great. My light is shaded from the beer. My unit is not a 100% air tight.

Bobby_M said:

It should work but don't you want to shield the wort from the light? Maybe if you can at least shade it with a piece of sheet metal. Perhaps a heat rock for a lizard tank would be better.

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If you use a normal incandescent bulb, you don't need to shield your wort from it.

If you are paranoid about it, wrap foil around the bulb.

IN response to the original question, you can do this. However, you need to get the right type of controller. Most controllers are set up to turn ON when the temp gets too HIGH. You want one that operates the other way; ON when temp too LOW.

I built a little heater out of a cheap furnace thermostat and a lightbulb to accomplish this.

Check out my fermentation fridge. I haev a 100 watt lightbulb connected to the Ranco Digital controller. The light bulb is under a coffee can, so it acts like a radiator.
https://cdn.homebrewtalk.com/gallery/showimage.php?i=1675

Brewsmith said:

Check out my fermentation fridge. I haev a 100 watt lightbulb connected to the Ranco Digital controller. The light bulb is under a coffee can, so it acts like a radiator.
https://cdn.homebrewtalk.com/gallery/showimage.php?i=1675

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Nice. One thing I regret having done was buying the single-item controller instead of the dual-item controller.

Now without the link... and a little more info. If you get the digital controller, you can set it to heat or cool. Right now my garage stays too cold, so I have it set to heat. My next brew is going to be a lager, so I'll switch it to cool.

Walker-san said:

Nice. One thing I regret having done was buying the single-item controller instead of the dual-item controller.

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That temp controller was one of the best homebrew items I ever spent $100 on. And rigging up the light cost be less than $10, including a 6 pack of bulbs.

I use a light bulb on a Ranco temperature controller to heat my beer fridge that (unfortunately) sits in the garage. It gets pretty cold up here in Alberta in the winter, but the bulb has never had any problem keeping up.

I also use an infra-red bulb for heating a reptile terrarium, so light spoiling isn't an issue at all. But a 100W bulb wrapped in foil works pretty well, too.

Also, watch eBay for good deals. I got my Ranco single-stage controller for $25 and I got a Johnson controller (non-digital, but more sensitive) for $14. I had to wire them myself, but that's easier than building a SS braid manifold.

This is a great and very timely thread for me. The compressor on our fridge just went bad and we are in the process of replacing the fridge. I've been looking for a good insulated box to ferment in and I think this would be perfect. I really don't need cooling. In the summer the average high temp is probably 65-70f, and it's a very rare day if it gets above 80f. On the other hand we get some pretty nasty cold weather in the winter time. I'd like to rig up a thermostat and light bulb heater for the dead fridge. The question is how much above ambient temperature could I keep the fermentation space? I've got no problem doing lagers in the winter and ales in the summer, but with low temps in the winter around 0f (sometimes colder) would I be able to keep my fermentations in the 40s?

Bobby_M said:

It should work but don't you want to shield the wort from the light? Maybe if you can at least shade it with a piece of sheet metal. Perhaps a heat rock for a lizard tank would be better.

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Just place a dark T-shirt over it.

IowaStateFan said:

This is a great and very timely thread for me. The compressor on our fridge just went bad and we are in the process of replacing the fridge. I've been looking for a good insulated box to ferment in and I think this would be perfect. I really don't need cooling. In the summer the average high temp is probably 65-70f, and it's a very rare day if it gets above 80f. On the other hand we get some pretty nasty cold weather in the winter time. I'd like to rig up a thermostat and light bulb heater for the dead fridge. The question is how much above ambient temperature could I keep the fermentation space? I've got no problem doing lagers in the winter and ales in the summer, but with low temps in the winter around 0f (sometimes colder) would I be able to keep my fermentations in the 40s?

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If you are asking whether a bulb is enough to keep the fridge warmed at 40 F even if it is at 0 F outside, the answer is yes. My garage right now is below -5 F, and the interior of the bulb-heated fridge is at 40 - 45 F. It is also the very rare occassion that I open the door and see the bulb on, which tells me that it isn't cutting in very often.

Besides, you could easily run multiple bulbs or a small space heater if you were really worried that one bulb wasn't keeping up, but I am certain it wouldn't be necessary.

I am currently running a small space heater in my 22 ft^3 freezer. I paid 12 bucks for it, and I only see a 3 degree temperature swing.

You should put your light bulb down at the bottom of the freezer and the thermostst near the top of the freezer. This way you will get more evenly heat in the freezer. Heat will rise. If you plan to go this way.

Cool, that's exactly what I was asking. It's good to know this should work before I invest a lot of time. Thanks.

Another reason a small heater or heat rock would be better is that light bulbs do burn out after so many on/off cycles. I'd imagine even an old hair dryer would work but it would be nice to be able to make the blower motor run a little slower. That noise would freak me out going on and off.

I have the temp control from 3B, it has the cord with the therm on the end, diesigned to insert in the stainless sleeve into the wort. It has always been used to keep my temp cool, now with the freezing cold my garage fridge is not holding temp. Can I use the same device to keep my fridge warm enough?

Thanks,
Rick

Eastside Brewer said:

I have the temp control from 3B, it has the cord with the therm on the end, diesigned to insert in the stainless sleeve into the wort. It has always been used to keep my temp cool, now with the freezing cold my garage fridge is not holding temp. Can I use the same device to keep my fridge warm enough?

Thanks,
Rick

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Sorry, I am not familiar with the 3B temperature controller. But for what it's worth, both my Ranco and my Johnson controller can do heating or cooling control (but the Johnson requires re-wiring).

Even if the 3b can't do heating, you could always add a heat source (e.g., light bulb) to the interior of the fridge. I have heard of people using electric timers to add just the right amount needed. Unfortunately, your light bulb and temperature controller (cooling) would be fighting one another, but with a timer you could probably minimize that. Just a couple of ideas potentially worth consderation.

I used the cheapie heat/cool one from homeless depot, like the one pictured, except it has the cool side with it. it will do both and all you have too do is change one wire for heat/cool. If you are really ambitious, you could run the controller to a switch, one side cool the other heat. I used it in my pink foam ferm chiller for a couple of years, it worked/works great. I still have it, it's just not in use at this moment.

Sorry, my temp controller in a Rankin. controller is set up to plug into a electrical outlet and then the fridge is plugged into it, I guess i could just get a small light fixture and run a cord out to the temp comtroller and then set temp. the bulb should only go on if temp drops? What kind of light bulb would be the best?

Thanks

What about that brew belt or something like it

Eastside Brewer said:

Sorry, my temp controller in a Rankin. controller is set up to plug into a electrical outlet and then the fridge is plugged into it, I guess i could just get a small light fixture and run a cord out to the temp comtroller and then set temp. the bulb should only go on if temp drops? What kind of light bulb would be the best?

Thanks

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I use an infra-red light bulb that is designed to heat a reptile terrarium. It doesn't emit the wavelength of light that will harm beer, and generates considerable heat.

FlyGuy said:

I use an infra-red light bulb that is designed to heat a reptile terrarium. It doesn't emit the wavelength of light that will harm beer, and generates considerable heat.

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Yeah - and it protects your beer from meteors

dcbrewmeister said:

Yeah - and it protects your beer from meteors

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Actually, so far yes -- seems to work for that too!

We just pulled our old (dead) fridge out and I tried a little experiment. The fridge is sitting outside on my deck. I put a lamp with a 100 watt lightbulb in it overnight. I also placed a thermometer in a glass of water. Our overnight low was 26 F and the thermometer read 120 F this morning. I really don't have a good place in the house to do my fermenting so this will work great. With a thermostat hooked up to the light bulb I should be able to keep the temp in fermentation range. I could even do ales in the winter! On the rare days when the temp gets warmer than 75 F here, I could use ice to keep the fridge cool - think "ice box".

One stupid question. I know I'm trying to warm the fridge instead of cool it, but would it be possible to rewire the existing thermostat to work with my light bulb setup?

I doubt you could do it. Leave it in tact and use it in the summer, best move it indoors though, itt'll use a lot of energy to keep it cool.


On tip I heard was to fit it to a timer and just set the timer to come on for 15 minutes 5 times a day. Measure the temp and adjust the timer to get the rewuired temp. It only takes a few days to get it sorted.

orfy said:

I doubt you could do it. Leave it in tact and use it in the summer, best move it indoors though, itt'll use a lot of energy to keep it cool.


On tip I heard was to fit it to a timer and just set the timer to come on for 15 minutes 5 times a day. Measure the temp and adjust the timer to get the rewuired temp. It only takes a few days to get it sorted.

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Thanks, I really didn't think I could use it but I was hoping to save a couple of bucks. BTW, the compressor is dead and I won't be using the fridge as a cooler. I have the opposite problem most of you have - I need to warm my fermentation area. My house is pretty small, and I don't have a basement, so I really don't have a good place to do my fermenting. I've been using the crawlspace and doing lagers, but that is a real PITA. I'm looking for a better solution and I think leaving the fridge outside (or maybe in my shed) will work. In the winter our temps range from -10 F to 45 F (typical high is about 35 F) and in the summer they range from 35 F to 80 F (typical high is 70 F). With those ambient temps, I'm planning to use the dead fridge and a light bulb to stabilize the fermentation temp in the lager range in winter and ale range in summer. For the few times that I may need to cool it I think a block of ice would probably work.

There's no reason you can't freeze plastic bottle with tap water and use those to lower the temperature if required.

As for light bulbs you can use a normal room thermostat or just change the wattage of the light bulb. I'd use a thermometer with a remote probe.

You can pick up cheap digital in/out thermometers in the uk for around $10.

Yes, you should be able to do what Orfy says with a thermostat -- just look household thermostats that are designed to run baseboard heaters. They are designed to switch a 110 v line, and should work wonderfully inside a fridge for heating purposes. They are also the least expensive type of household thermostat to purchase.

Note: stay away from most of the furnace thermostats because they are typically designed for 24v systems, not 110v.