Thermostat controlled light bulb heater(pictures inside)

[Nivekt]

Hello All,

I currently use a Honeywell CT33 thermostat to control a fan in my fermentation chamber. Its basically this setup:

The inside wiring of this thermostat looks like this:

Now that winter is upon us. I need some way to use this thermostat to control the heater I built which is this simple light bulb in a paint can:

Now, my question is, which terminals on the thermostat do I connect the power cable leads to from the paint can heater so that when I switch the thermostat to the heat option, it will turn on and off the paint can heater based on the thermostat level I set?

Thank you for your help with this!

 

[raysmithtx]

I have never seen a thermostat that will switch 120VAC. They are all designed to switch low voltage DC like the computer fan you show. The low voltage from the thermostat then controls a separate relay (located in a homes A/C unit and/or heating unit) to switch AC voltage devices.

You will need a separate relay and then some way to safely wire and mount everything. It would probably be cheaper, safer and certainly easier to buy a STC1000 for about $14. They are designed to do exactly what you are trying to do.

 

[z-bob]

Some of them are designed to switch 110v. It should say so on the package. You are right tho', the default is something like 20v.

 

[Nivekt]

Thank you for the replies gentlemen. You are correct. After further research I can see now that it is intended only to be used with low voltage.

I think I will go for something like this instead of the STC just so I dont have to deal with the wiring aspect:

http://www.amazon.com/dp/B000E7NYY8/?tag=skimlinks_replacement-20

 

[Scotty_g]

I got a new furnace a few years ago when the old one burned out its heat exchanger, and I saved the 24-V transformer from it. HVAC company gave me a fancy programmable thermostat so the old digital one (bog-standard 15-year-old Honeywell) was available...and when I started chatting with the furnace guy, he dug around in his van and gave me an old DPST 120V relay.

So, I use the transformer to supply 24 VAC to the thermostat; when it calls for heat, the thermostat switches the 24 VAC to the relay. The relay snaps in, and I have a fan and a light bulb connected to the two outputs.

The old fan I had laying around was a 120-mm unit from a 20-year-old computer. When it starts, it sounds like my fermenter box is preparing for takeoff - so I normally disable it. The relay snaps in pretty loudly as well, but I've gotten used to it.

If you weren't trying to do this as a challenge to empty out your junk box (I bought nothing), you could easily find a smaller solid-state relay that could handle a 100-W bulb or something. I'd find a less-beefy (quieter) fan than the one I have; if may be possible to hook the fan and light bulb up in series so they both run under-voltage (and therefore under-powered). If you had a 12-VDC fan (a good and inexpensive choice - you can buy them from any computer store/website), I would put a small transformer in series with your light bulb. Use a rectifier to provide DC to the fan.

I don't know what range of voltage a thermostat will switch. You'd have to consult the manual. You'll have to match the transformer output and relay coil voltages.

 

[day_trippr]

What the OP is looking for is an inexpensive analog electric baseboard heater thermostat...

Cheers!

 

[alphaomega]

I think I will go for something like this instead of the STC just so I dont have to deal with the wiring aspect:

You should get some fermwrap or a tubular heater or something as well instead of that paint can heater. That is actually the worst one I've seen, as you have the cable without any gland directly through the side.
Aside from that, it can get hot inside the paint can and could potentially melt plastic.

 

[Nivekt]

Thanks for the ideas Scotty_g but that is a bit too advanced for someone of my skill level. Im looking for a mostly simple plug and play operation.

Thank you day_tripper! That is a much cheaper and simpler option for what I need. Buying that now.

alphaomega. The picture of the can heater I used is not my can heater. It was a picture taken from the original designer taken from his website: http://www.wortomatic.com/articles/Fermentation-Can-Heater

When I built my can heater I made the cable come out the top of the lid. After running for several hours the area where the cord comes through the top of the lid only gets to 120F.

So far Ive just been running the heater manually and keeping an eye on temps until I get it just right. My fermentation chamber is very well insulated. Here is a video of it I made:

[ame]https://www.youtube.com/watch?v=bAwIVWUl5tk[/ame]

 

[alphaomega]

alphaomega. The picture of the can heater I used is not my can heater. It was a picture taken from the original designer taken from his website: http://www.wortomatic.com/articles/Fermentation-Can-Heater

When I built my can heater I made the cable come out the top of the lid. After running for several hours the area where the cord comes through the top of the lid only gets to 120F.

Oh, I whish I could unsee that... That is awful. Cable through the metal, without a gland, no grounding, minimal ventilation and putting it up on a website for others to copy...
I'm just not a fan of bulb in a paint can heaters. And even worse when the simple measures to make it a bit safer is avoided.
Put the lamp fitting in the bottom, so the heat rises away from it, have some ventilation, make some 'legs' so it won't sit directly on plastic, ground the can, use a cable gland for the love of <insert god of choice here>, use low wattage bulb (like an oven bulb for example), possibly include a thermal fuse. Simple things to at least reduce risks to a minimal. Remember this will be used unsupervised for extended periods of time, while you're at work and sleeping. It is after all a heater you put in an enlosed space made of pretty flammable stuff.
I'm not telling anyone what to do, it's your life, just offering my opinion on the matter.

 

[Nivekt]

Oh, I whish I could unsee that... That is awful. Cable through the metal, without a gland, no grounding, minimal ventilation and putting it up on a website for others to copy...
I'm just not a fan of bulb in a paint can heaters. And even worse when the simple measures to make it a bit safer is avoided.
Put the lamp fitting in the bottom, so the heat rises away from it, have some ventilation, make some 'legs' so it won't sit directly on plastic, ground the can, use a cable gland for the love of <insert god of choice here>, use low wattage bulb (like an oven bulb for example), possibly include a thermal fuse. Simple things to at least reduce risks to a minimal. Remember this will be used unsupervised for extended periods of time, while you're at work and sleeping. It is after all a heater you put in an enlosed space made of pretty flammable stuff.
I'm not telling anyone what to do, it's your life, just offering my opinion on the matter.

Are you aware that the melting point of extruded polystyrene is 240c? What exactly are you concerned with? I'm all for safety but there is a point where obvious risk can be measured. What exactly is it that you envision is going to happen? At what point did you build one of these heaters and determine that its design, through careful measurement, lies outside of reasonable safety? Are you just making wild assumptions with no real data?

Can you recommend a comparable replacement for under $10? Fermwrap is $40 per carboy and my setup can hold three and I have no idea what a tubular heater is. How about you post up some direct links to a solution you feel is adequate given my specific fermentation chamber?

Thanks.

 

[alphaomega]

I'm not looking to start a debate here man...
But I'll try to address your questions in turn.

Are you aware that the melting point of extruded polystyrene is 240c?

I am now. I'll take your word for it, though I'm sure it could depend (at least some) on the exact composition. But that is not the point, the point is when it burns, it burns well.

What exactly are you concerned with? I'm all for safety but there is a point where obvious risk can be measured. What exactly is it that you envision is going to happen?

Are you really? If so, then I'd think at least you'll see there is some validity to the points I made earlier. I'm not saying that if you don't do as I say you will burn down your house or get electrocuted. If you don't then that is a good thing. What I did say is that you can at least make some easy adjustments to make it as safe as possible.
There are always risks, without a gland, you don't have strain relief and the cable will chafe against the metal edge. A short need not blow a fuse and can start a fire or lead to electrocution. Plastic parts can warp in the heat, also causing shorts. And you are using the stuff in a way in which it was not intended. Do you think you would later regret making some cheap/easy adjustments to increase the safety? You very well may not need to regret NOT making them as well, but the consequences are worse.

At what point did you build one of these heaters and determine that its design, through careful measurement, lies outside of reasonable safety? Are you just making wild assumptions with no real data?

What do you even mean by this? Do I need to sample my own urine daily and take tasting notes before I conclude I don't like drinking it? Well, maybe I do... But I'll take a not so wild guess and use common sense and the usual best practice instead. How many appliances do you see that don't have strain relief? Think there might be reason for that?

Can you recommend a comparable replacement for under $10? Fermwrap is $40 per carboy and my setup can hold three and I have no idea what a tubular heater is. How about you post up some direct links to a solution you feel is adequate given my specific fermentation chamber?

Ok, so if money is the bottom line I'd go with a couple of these and one of this.
I'm not going to hand you any more links, do you own homework. I do however believe that some things could be worth a few extra bucks.

So, yeah... I'm sorry if this was a bit of an abrasive answer, but I kind of got rubbed the wrong way by yours.
As I said earlier, you do what you want, I just offered a few ideas on how to make it at least as safe as possible. I don't think those were in any way bad ideas, but rather corrections to a less than optimal design. If you think I'm a paranoid safety nazi, then just say "Good ideas, I'll see if I get around to it some day" and leave it at that, don't try and sell me that I'm in the wrong here.

Thanks.

Yw

 

[z-bob]

Making that hole in the can just a little bigger and installing a rubber grommet would go a long way to improve the safety. Tie a "UL knot" on the inside for strain relief.

What about using an aquarium heater to keep a water-bath warm? You get a waterproof heater and thermostat and cord all in one package.

 

[alphaomega]

Making that hole in the can just a little bigger and installing a rubber grommet would go a long way to improve the safety. Tie a "UL knot" on the inside for strain relief.

That would definitely be an improvement, but a gland even better.

What about using an aquarium heater to keep a water-bath warm? You get a waterproof heater and thermostat and cord all in one package.

And with the added excitement of mixing water and electricity
Seriously though, that might work. I'd add a properly sized fuse to go with that, and be more worried about the extra moisture that would produce that the safety aspect.

The best product I've found, is the tubular heater though. I don't know if they are called that in the US, or even available. I got mine from the UK. Reasonably low wattage and high surface area and built in overheating protection. Otherwise I'd go the reptilian heat cable route or if you know what you are doing, build your using power resistors, scrap heat sinks and a fuse + thermal fuse.

 

[Nivekt]

Making that hole in the can just a little bigger and installing a rubber grommet would go a long way to improve the safety. Tie a "UL knot" on the inside for strain relief.

What about using an aquarium heater to keep a water-bath warm? You get a waterproof heater and thermostat and cord all in one package.

I like the idea for the knot and grommet. Ill look into it. I'm sure the local Ace Hardware has what I need. Thanks.

I've seen people use those aquarium heaters before but dont really see the advantage over my current setup. I probably would have gone this route initially had I discovered it before I made my can heater though to be honest as I like the fact that it is a proven and marketable product.

I took some more measurements of the can heater earlier today. After running for 3 hours continuosly no point on the can got above 115F. With a 60 watt bulb it seems to work great. Once I add the thermostat for it I think its continual run time will be greatly reduced.

Thanks for the input.

 

[JustLooking]

For $18 plus free shipping you can get a fish tank heater to put in a jug of water.

 

[jimdkc]

How about this: 100W reptile heater... screws into a light bulb socket. Under $10. The 100 Watts is put towards generating heat instead of light!

EDIT: Or here... Any wattage between 25 and 250!

 

[JustLooking]

How about this:

I looked into the reptile heaters, but went with the aquarium heater because the temperature was adjustable and the set-up seemed like it would be easier than coming up with or buying a light fixture that would fit in a small space. (Although one of the porcelain light fixtures that are used in basements could be inverted and are pretty cheap.)

A bleach bottle with the top cut off and filled with water was the only additional thing I needed with the aquarium heater.

 

[Nivekt]

I looked into the reptile heaters, but went with the aquarium heater because the temperature was adjustable and the set-up seemed like it would be easier than coming up with or buying a light fixture that would fit in a small space. (Although one of the porcelain light fixtures that are used in basements could be inverted and are pretty cheap.)

A bleach bottle with the top cut off and filled with water was the only additional thing I needed with the aquarium heater.

So the aquarium heater has built in thermostat control? How easy is it to maintain a specific temperature in your fermentation chamber? Do you have to adjust it often or does it hold well?

 

[JustLooking]

So the aquarium heater has built in thermostat control? How easy is it to maintain a specific temperature in your fermentation chamber? Do you have to adjust it often or does it hold well?

You know, I never checked it for accuracy. I have a freezer with a Johnson A419 controlling the cooling. This time of year, my basement is colder than I want my fermentation, so I set the fish tank heater at the temperature I want and let the freezer and A419 do the actual controlling. The freezer almost never goes on, but the temperature on the A419 readout is pretty constant. A dual temperature control would be better for sure, but ........