question about t-stats

[gncz73]

hi i really don't think this has ever been address here in the forms. so here i go.



let's say i have a johnson controls or any of the other on/off type t-stat and it's hooked up to 20 feet of flexwatt.



no let's say i have a herpstat or any of the other proportional type t-stat and have it hooked up to 20 feet of flexwatt.


now which setup would use more power per month?

i feel the on/off type would use more power as it would be more like turn a light on and off, as the proportional is like a dimmer it just lowers the amount of energy that is being used.

[mikerccie]

Here's my take on it, it lines up with some other folk's websites (that sell both the on-off and the proportional type).

An off-on type of t-stat is using drawing 100% of it's current load when on and 0% when off.

The Proportional type draw 100% of it's current load all the time and and deliver some portion of it to the heating element.

I don't think the simple resistor-type heaters that we use don't really have a "Startup penalty" like turning on certain types of lights with ballasts or inductive motors that have a start current to get rolling.

So, to my simple mind the on/off type are going to use the least energy.

Now, you can start a whole other discussion around what type is BETTER for your snakes.

[kavmon]

i've never done any test on this, might have to take amp draws and find out. normally a control device (stat) does not take full load unless something is needing full load(heat source) ie you can have a unit on a 30 amp breaker and it only needs and draws 19 amps to run. i might have to play around with some flex and see! at first thought if the flex isn't going full blast, i see no reason why a helix would use full load?


vaughn

[jglass38]

I'm curious to see how this shakes out. I would have thought a proportional only draws enough power as it needs to send to the device in question. My vote (with no basis in fact) would be that the proportional would use less power.

[justcage]

You have to think about the analog thermostat completly turning off therefore no power but than again a prortional stat will turn off the power completly as well. My vote would have to be for an analog...

[kavmon]

did some testing on the flexwatt. tested a 5ft. piece of 11in. flex rated at 20 watts/ft. so 100 watts total.

plugged flex directly into wall =.79 amps
plugged proportional stat in wall = .77amps under full load
at setpoint with prop. stat flex = .24 amps
over setpoint = no amps
did not test a ranco yet, i was only really curious about proportional stats. i really don't know which one would cost less to run! the prop. ones would run more but only at .24 amps, the rancos would run less but at .77 amps when they do come on. i vote for proportional and stability. and 1/4 of 1 amp is nothing in the way of power usage. reading this on your monitor is more power! lol


vaughn

[ARamos8]

interesting. I would think that the on/off would use less but as vaugh stated the current draw of a prop on a constant basis is nomial. So the underlying catch here would then be "How efficient is the enclosure?" This I'm sure would minimize the frequency at which both types of units ramp up to maintain the desired temps. Good question gncz73.

[jglass38]

Vaughn, the mad scientist.

[kavmon]

i don't know about the scientist part, but mad for sure! lol

as a kid i was always taking things apart and seeing how they worked. some of them were put back together!


vaughn

[jglass38]

i don't know about the scientist part, but mad for sure! lol

as a kid i was always taking things apart and seeing how they worked. some of them were put back together!


vaughn

I spent most of my childhood falling on my head and generally injuring myself. And unfortunately it carried over into adulthood. Moral of the story, make sure you have good health insurance!