What are the most efficient heaters? / Heater comparison

[MikeTheNewbie]

Hi I've been looking for heater efficiency details and benchmarks but for some reason I haven't found a good source.
I'm considering adding heating to my power outage setup and since heaters are the most power hungry devices I'm trying to find the most efficient option.
Does anyone know if there are any comparisons or benchmarks out there. It feels like one of those BRS investigates type of comparison should exist that compares different technologies like titanium heaters vs glass heaters etc.
Any help will be appreciated.

 

[Formulator]

The reason you won’t find this type of comparison is because electrical heating is pretty much all about 100% efficient. 1 watt hour = 3.4 BTU. Energy is readily and directly converted to heat. The only benefit of titanium is removing the risk of glass breakage in your tank.

 

[MikeTheNewbie]

Wow, I wouldn't have expected that. Doesn't the material conductivity play a role? I wonder if glass vs and titanium have different heat conductivity properties that could make one more efficient than the other...

 

[Formulator]

Wow, I wouldn't have expected that. Doesn't the material conductivity play a role? I wonder if glass vs and titanium have different heat conductivity properties that could make one more efficient than the other...

That won’t affect efficiency, just rate of heating the water column, and in water when comparing glass with titanium, it is negligible.

 

[BeanAnimal]

Wow, I wouldn't have expected that. Doesn't the material conductivity play a role? I wonder if glass vs and titanium have different heat conductivity properties that could make one more efficient than the other...

Every watt of energy consumed ends up as heat in the water. No, it does not make a difference.

 

[Naekuh]

Wow, I wouldn't have expected that. Doesn't the material conductivity play a role? I wonder if glass vs and titanium have different heat conductivity properties that could make one more efficient than the other...

that has more to do with how fast it can transport heat, and not actually efficiency.

eventually all things in a system goes to equalibrium, so whatever energy was spent to heat will go to the system, which makes it very efficient.

Speed in how fast equalibirum is achieved is however determined by thermal conductivity.

 

[PotatoPig]

Wow, I wouldn't have expected that. Doesn't the material conductivity play a role? I wonder if glass vs and titanium have different heat conductivity properties that could make one more efficient than the other...

It’s shockingly easy to make efficient electric heaters, even if you’re not trying to. For example: The old incandescent lightbulbs were 98% efficient… provided you used them as heaters.

 

[Malum Argenteum]

electrical heating is pretty much all about 100% efficient

Resistive electric heat is exactly 100% efficient. Well, since in an electrical circuit heat is wasted energy, electric heaters are all zero percent efficient. If there were any electricity that wasn't being turned into heat, it would be wasted electricity, which is heat.

 

[MikeTheNewbie]

What about the Helio PTC Smart Heaters, they state they are energy efficient on their website.
Could those make any difference?

 

[BeanAnimal]

What about the Helio PTC Smart Heaters, they state they are energy efficient on their website.
Could those make any difference?

No. a Watt is a Watt. All of the PTC marketing that says that they are “more efficient” than other electric heating elements is just related marketing nonsense, be it for aquariums or space heaters.

 

[Malum Argenteum]

Mike, one option to reduce the load on a backup system would be to use two undersized heaters on the regular system, but only one of those on the backup system; this would reduce the energy draw at on the backup system (though this would not reduce the energy use over a long period of time). This can be helpful if the weak link in the backup system is the inverter capacity (rather than the battery capacity). I have some tweaks like this on my backup arrangement, which is a generator that is near capacity.

Another option would be to set things up so that the temp set point during the backup condition is lower than normal, though not so low that things will die. This would reduce overall power consumption during a backup condition.

 

[Formulator]

I think PTC heaters are an interesting discussion. While they are not more efficient in converting electricity to heat, in practice they may actually consume slightly less power, though this is not due to a difference in how much your water is heated with a set amount of electricity. I think they have the ability to more precisely regulate temperature due to the self regulating nature of the resistor material. For example, lets say your thermostat is set to turn the heater on at 78F and off at 78.5, your traditional heater will kick on at 100% power when the water temp reaches 78 and 100% off at 78.5, but your water temp may actually overshoot and come up to 78.6F before starting to fall again. With a PTC heater, if I understand them correctly, the electrical energy consumption starts to decrease as it gets close to 78.5 before turning off completely. In this way, it doesn’t over shoot your set-point and uses only as much energy required to hit that set-point. So it is more precise, and may save a few cents worth of electricity. That said, this difference is extremely minor and I do agree that the majority of efficiency claims around PTC heaters are just clever marketing.

I am a chemist, not a ceramics engineer, and we are now getting past my depth so I could be wrong, but this makes sense to me.

 

[BeanAnimal]

I think PTC heaters are an interesting discussion. While they are not more efficient in converting electricity to heat, in practice they may actually consume slightly less power, though this is not due to a difference in how much your water is heated with a set amount of electricity. I think they have the ability to more precisely regulate temperature due to the self regulating nature of the resistor material. For example, lets say your thermostat is set to turn the heater on at 78F and off at 78.5, your traditional heater will kick on at 100% power when the water temp reaches 78 and 100% off at 78.5, but your water temp may actually overshoot and come up to 78.6F before starting to fall again. With a PTC heater, if I understand them correctly, the electrical energy consumption starts to decrease as it gets close to 78.5 before turning off completely. In this way, it doesn’t over shoot your set-point and uses only as much energy required to hit that set-point. So it is more precise, and may save a few cents worth of electricity. That said, this difference is extremely minor and I do agree that the majority of efficiency claims around PTC heaters are just clever marketing.

I am a chemist, not a ceramics engineer, and we are now getting past my depth so I could be wrong, but this makes sense to me.

In theory tighter regulation may mean less overall power due to overshoot - but for most systems with modest size heaters, that overshoot is not going to exist. The heater just does not have that much thermal mass compared to the system mass. If it was a 500W heater that weighed 8 pounds and the tank volume was 10 gallons.... sure!

 

[Borat]

only buy organic probiotic heaters - they accelerate expensive sps growth

 

[BeanAnimal]

only buy organic probiotic heaters - they accelerate expensive sps growth

I prefer homeopathic - just a few molecules of heat is all it takes.

 

[MikeTheNewbie]

I think PTC heaters are an interesting discussion. While they are not more efficient in converting electricity to heat, in practice they may actually consume slightly less power, though this is not due to a difference in how much your water is heated with a set amount of electricity. I think they have the ability to more precisely regulate temperature due to the self regulating nature of the resistor material. For example, lets say your thermostat is set to turn the heater on at 78F and off at 78.5, your traditional heater will kick on at 100% power when the water temp reaches 78 and 100% off at 78.5, but your water temp may actually overshoot and come up to 78.6F before starting to fall again. With a PTC heater, if I understand them correctly, the electrical energy consumption starts to decrease as it gets close to 78.5 before turning off completely. In this way, it doesn’t over shoot your set-point and uses only as much energy required to hit that set-point. So it is more precise, and may save a few cents worth of electricity. That said, this difference is extremely minor and I do agree that the majority of efficiency claims around PTC heaters are just clever marketing.

I am a chemist, not a ceramics engineer, and we are now getting past my depth so I could be wrong, but this makes sense to me.

Hey @Formulator @BeanAnimal and @Malum Argenteum thanks for the help. Sounds like I'll keep my existing titanium heaters but put them on separate controllers. Have one at a higher setpoint running over the AC backup. The non backed up would be the one that does the fine tunning and stops working in case of an outage.

 

[Pistondog]

Hi I've been looking for heater efficiency details and benchmarks but for some reason I haven't found a good source.
I'm considering adding heating to my power outage setup and since heaters are the most power hungry devices I'm trying to find the most efficient option.
Does anyone know if there are any comparisons or benchmarks out there. It feels like one of those BRS investigates type of comparison should exist that compares different technologies like titanium heaters vs glass heaters etc.
Any help will be appreciated.

Maybe explore tank insulation in the event of power failure to minimize heat loss. Something you could add quickly to minimize heat loss thru glass to minimize watts needed to maintain temperature.

 

[fishyjoes]

Maybe explore tank insulation in the event of power failure to minimize heat loss. Something you could add quickly to minimize heat loss thru glass to minimize watts needed to maintain temperature.

I've actually done this testing. The thing that makes the most difference is adding a solid lid.
Insulating the sides helps a bit too, but not as much as simply adding a solid lid.

 

[Pistondog]

I've actually done this testing. The thing that makes the most difference is adding a solid lid.
Insulating the sides helps a bit too, but not as much as simply adding a solid lid.

Makes sense, just want to insure adequate gas exchange. I run a bubbler from outside the tank to get some exchange.