Winter water?

[coop410silkies]

A bit of both, the link I posted above has a section on dimming and what it does to the bulb...
Yes, again the link I posted goes into damage caused to the bulb by heating and cooling cycles...
Look into PTC heaters, little to no fire risk, long life and very reasonably priced on Ebay... Most current commercial space heaters now use PTC elements...

So right after I asked you all these questions, instead of going immediately to your links, I yahooed "heating elements for incubators" and found a BYC listing. I hit that and found your posts about these PTC heating elements, and checked them out briefly on eBay.. They look like what I've been needing, and I was searching for information on them when your post came up. Thanks so much for steering me here.

Thanks, too, for the other links and for answering my questions.

 

[coop410silkies]

So, MeepBeep, do you think one of these PTC HEATERS, say of 50 watts, could work in Ron P's modified "tin can heaters"?,

 

[MeepBeep]

So, MeepBeep, do you think one of these PTC HEATERS, say of 50 watts, could work in Ron P's modified "tin can heaters"?,

For all intents you can assume a 50W PTC is going to produce the same amount of heat as a 50W incandescent bulb... But if you want to start splitting hairs a PTC should produce about 5-10% more heat as it's not wasting that 5-10% of wattage to produce visible light...

One thing to note though is the direction of the heat, in Ron's design he has multiple layers (directional bulb, plus reflector housing) of shielding directing the heat to the top of the upside down pot, so you will need to incorporate the same type of directional shielding on a PTC heater to get the similar results as heat directed to the sides of the pot and down to the ground is essentially waste in this design...

 

[coop410silkies]

For all intents you can assume a 50W PTC is going to produce the same amount of heat as a 50W incandescent bulb... But if you want to start splitting hairs a PTC should produce about 5-10% more heat as it's not wasting that 5-10% of wattage to produce visible light...

One thing to note though is the direction of the heat, in Ron's design he has multiple layers (directional bulb, plus reflector housing) of shielding directing the heat to the top of the upside down pot, so you will need to incorporate the same type of directional shielding on a PTC heater to get the similar results as heat directed to the sides of the pot and down to the ground is essentially waste in this design...

OK, I see your point. Even so, one mounted in a heat reflective dome might do a halfway decent job. Perhaps one could replace the light bulb as a heat source in a cinder block? I was just on eBay looking at these PTCs, and they are said to produce a consistent heat and don't need a thermostat. Or something like that. Don't really know what that means. That the wattage needs to be matched to the size of container? Could a high watt PTC make the pot too hot? I really need to research these. Thank again.

 

[MeepBeep]

I was just on eBay looking at these PTCs, and they are said to produce a consistent heat and don't need a thermostat. Or something like that. Don't really know what that means.

It means exactly what it says, they don't need a thermostat, they self regulate their heat output... The material they are made of has a very low resistance when cold, so it conducts electricity and heats up, as it heats up the resistance increases and at a certain point the resistance is so great it automatically shuts itself off until it cools back down and starts heating again... This allows them to be designed to self regulate at a given temp... If you purchase one pay note to the design and make sure it's one set to self regulate at higher temp in this application, the general self regulated range from many manufactures is usually between 100° and about 500°... You likely don't want one that is only getting to 100° for this application, you want one that is several hundreds of degrees, to give reference a 60W incandescent bulb is about 260° on the surface in ambient room temp air, cooler outside in the winter...

That the wattage needs to be matched to the size of container? Could a high watt PTC make the pot too hot?

Yes, the wattage should match the bucket size, in general for submerged heaters you want about 5 Watts per gallon, but for this design 10 Watts a gallon is probably more ideal, but you might even need more in extremes... And yes too much heat could make the pot too hot, but it would take a lot to get to that point in a winter environment with indirect heat like this design...

 

[coop410silkies]

It means exactly what it says, they don't need a thermostat, they self regulate their heat output... The material they are made of has a very low resistance when cold, so it conducts electricity and heats up, as it heats up the resistance increases and at a certain point the resistance is so great it automatically shuts itself off until it cools back down and starts heating again... This allows them to be designed to self regulate at a given temp... If you purchase one pay note to the design and make sure it's one set to self regulate at higher temp in this application, the general self regulated range from many manufactures is usually between 100° and about 500°... You likely don't want one that is only getting to 100° for this application, you want one that is several hundreds of degrees, to give reference a 60W incandescent bulb is about 260° on the surface in ambient room temp air, cooler outside in the winter...
Yes, the wattage should match the bucket size, in general for submerged heaters you want about 5 Watts per gallon, but for this design 10 Watts a gallon is probably more ideal, but you might even need more in extremes... And yes too much heat could make the pot too hot, but it would take a lot to get to that point in a winter environment with indirect heat like this design...

Thanks. I understand that the heat generated is constant and set by the manufacturer, determined by that rubber cement stuff. BUT in only a very few of the PTCs I viewed on eBay did the manufacturer say what temperature it was set for. It's what I didn't understand. one site said the temperature could be finely tuned by varying the voltage. I have read of some new aquarium heaters that are preset and keep constant temperatures, and some that you can set yourself - and I think these are using the PTC elements. I am thinking that if a 75 watt regular light bulb can keep my water bucket from freezing, maybe that's the size PTC element I should get and plug it in through a thermocube. Maybe 60* These are cheap enough to try out, and if they work out, I will be ecstatic. There seem to be so many pros to using them.

The other application I am considering is an incubator. If I could find one that was set for 100* and was 150 watts, I would buy it tonight.

I will shop around. I may not be looking in the right places. Thanks for all your help.

 

[MeepBeep]

If I could find one that was set for 100* and was 150 watts, I would buy it tonight.

I would not trust it to self regulate for incubation, you can get cheap digital thermostats on Ebay that will work fine with the PTC, light bulb or other heaters to hold temp...

I just picked up a few of these, to turn on/off some stock tank heaters instead of investing in thremocubes and thus far they are working flawless, and actually save money because they measure the water temp not the air temp like thermocubes, I have it set to hold the stock tanks at 2°C (36°F)..

http://www.ebay.com/itm/331577078605?

And I have a few of these from earlier this year that also work well...

www.ebay.com/itm/181925440076?

 

[coop410silkies]

I would not trust it to self regulate for incubation, you can get cheap digital thermostats on Ebay that will work fine with the PTC, light bulb or other heaters to hold temp...

I just picked up a few of these, to turn on/off some stock tank heaters instead of investing in thremocubes and thus far they are working flawless, and actually save money because they measure the water temp not the air temp like thermocubes, I have it set to hold the stock tanks at 2°C (36°F)..

http://www.ebay.com/itm/331577078605?

And I have a few of these from earlier this year that also work well...

www.ebay.com/itm/181925440076?

OK, I have a couple of these digital thermostats. Haven't used them yet, but have tried others and like them a lot. This probably seems like a stupid question, but do you power the thermostat with a 12volt battery and use a relay to switch the stock tank heater on and off? My thermostats are AC, and the current my light bulbs draw is so small I don't use them with a relay. I am so happy the PTCs will work with these thermostats. So if PTCs are longer lasting and safer to use than light bulbs, why don't more people use them?

 

[bruceha2000]

What they are both incredibly poor at is their conversion of consumed Watts into lumens of light

ironic for a product designed to produce light...

Just like duct tape is good for lots of things ... except sealing ductwork

A bit of both, the link I posted above has a section on dimming and what it does to the bulb...
Yes, again the link I posted goes into damage caused to the bulb by heating and cooling cycles...
Look into PTC heaters, little to no fire risk, long life and very reasonably priced on Ebay... Most current commercial space heaters now use PTC elements...

I found a Pelonis site with PTC heaters. I ASSUME this is a much newer technology than > 20 year old Pelonis ceramic cube heater I have which still works fine and I see can STILL be purchased on Amazon?

Yes, the wattage should match the bucket size, in general for submerged heaters you want about 5 Watts per gallon, but for this design 10 Watts a gallon is probably more ideal, but you might even need more in extremes... And yes too much heat could make the pot too hot, but it would take a lot to get to that point in a winter environment with indirect heat like this design...

But what if you just plug it in and the ambient temp is varying from -20F to above freezing?

OK, I have a couple of these digital thermostats. Haven't used them yet, but have tried others and like them a lot. This probably seems like a stupid question, but do you power the thermostat with a 12volt battery and use a relay to switch the stock tank heater on and off? My thermostats are AC, and the current my light bulbs draw is so small I don't use them with a relay. I am so happy the PTCs will work with these thermostats. So if PTCs are longer lasting and safer to use than light bulbs, why don't more people use them?

Hmmm, looks like that would take a bit more skill/education to use than an off the shelf plug in the wall thing like a ThermoCube. Are there "kits" to turn these into a "consumer ready" product?

 

[MeepBeep]

OK, I have a couple of these digital thermostats. Haven't used them yet, but have tried others and like them a lot. This probably seems like a stupid question, but do you power the thermostat with a 12volt battery and use a relay to switch the stock tank heater on and off?

I use a 12v wall wart (wall adapter) to power the thermostat and then yes the relay on boards switched whatever device... Most of them have a 10A relay, so they are go to about 1200 Watts @ 120VAC...