Yep Punk In Drublic, I don't doubt that Steam is correct. I must be doing something wrong but I wish I knew what.
Can you do a Screen Shot of the Steam page with your Parameters?
Number of wraps for resistance
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Can you do a Screen Shot of the Steam page with your Parameters?
I get the same readings plugging in the type of wire, gauge, wraps and ID that the OP is claiming to be off. But as you mentioned earlier, what we do not know are the wire properties (as in the variances in alloys used and how this affects it’s resistance) the OP is using.
Yeah, but the heat capacity that Steam reports is clearly not related to mass, as the number is expressed in mJ/K (milli-Joules per Kelvin). So unit mass has already been taken out by multiplying the specific heat of the given metal type by the density of this same metal type. By playing with the volume of the coil you can easily find out the fact that the specific heat reported by Steam is actually the volumetric heat capacity (VHC) of the metal type multiplied by the volume of the coil.
About 3/4 the way down..
Steam Engine: Basic & advanced features: Pts. One & Two | E-Cigarette Forum
"Another ignored and misunderstood reference value (even more so than HF) is heat capacity (HC). It's important... but not as user critical as heat flux.
This is a representation of time-to-temperature efficiency... or how fast a coil will heat up - to the heat flux value. Time is directly relatable to the coil(s) mass."
Steam Engine: Basic & advanced features: Pts. One & Two | E-Cigarette Forum
"Another ignored and misunderstood reference value (even more so than HF) is heat capacity (HC). It's important... but not as user critical as heat flux.
This is a representation of time-to-temperature efficiency... or how fast a coil will heat up - to the heat flux value. Time is directly relatable to the coil(s) mass."
What I meant was the difference in specific heat between Nichrome 80 and Kanthal A1 (450 vs 460) appears small like you said, BUT... according to the official datasheet, at 200°C the specific heat of Kanthal A1 is 560. So if we can assume that the specific heat of Nichrome 80 is 435 at 20°C and 450 at 200°C (not really sure if that's correct...), then the average number for Nichrome 80 is still a whole lot smaller than the average number for Kanthal A1 (460 at 20°C, 560 at 200°C). So yeah... some people say this, others say that. Personally, I, am saying the difference in ramp up time (and cool down time) between Nichrome 80 and Kanthal A1 is clear as a bell, to which I'll add I'm talking from first hand experience.Yeah; I found either 435 or 450 specific heat for N80. Greater difference, yeah; much greater, not really. Taken density into account, Kanthal still wins overall, at least in theory.
However I´ve not found detailed numbers on how heat capacity changes in the temperature range that matters to us (20-250°C)
I don't "know" if Kanthal heats up slower then N80 or SS. All I hear is some people say this, others say that. Someday, maybe, I´ll order a roll of 0,3mm N80; SS and Kanthal and find out if I can feel a difference.
But in the end; idk if it matters all that much. If you´re unhappy with ramp up; using thinner wires will have a much bigger effect then changing coil material.
Punk In Drublic, Yes; good taste in music.
I (obviously) love Bolt Thrower. Shame about their drummer; would have loved to see more concerts of them.
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Sure, but the fact it isn't as critical has got nothing to do with this other fact, which is that Steam has got the numbers wrong. And, no, time is not directly relatable to coil mass, because instead, it is directly relatable to [volumetric heat capacity multiplied by volume].
I didn't bold that first part - it was the way it pasted. Didn't mean for it to stand out.
So what would be the heat capacity calculation?
You can either click on "Physical properties" and then scroll down to "Specific heat capacity", or download the datasheet as PDF, on here:Would you mind posting this data sheet? Thx
Kanthal® A-1 — Kanthal®
Specific heat multiplied by density equals volumetric heat capacity [of the metal type]. So, the heat capacity of the coil is the volumetric heat capacity [of the metal type] multiplied by the volume [of the coil].
Gotta admit that you have lost me. To my understanding the Heat Capacity is related to but not measured as the mass of the metal used. Steam was developed by ECF member @Dampmaskin – perhaps he can chime in and maybe explain the OP’s issues as well.
Yes, heat capacity of a substance is the amount of heat (energy) that the substance needs to absorb to make the temperature of the substance go up by one Kelvin, measured per unit mass, whereas the volumetric heat capacity, as the name suggests, is per unit volume, instead of per unit mass. To convert unit mass to unit volume, we multiply by density so that, if the volume of the coil is known to us, we can then take the volumetric heat capacity, and multiply it by this known volume, to arrive at the heat capacity of the coil, instead of the substance. The thicknesses and lengths of the wire strands we use for coil building determine the volume of the coil, not the mass of the coil. I.e., we design our coils by selecting wire gauge, wire length, and metal type. Not by selecting the mass of the wire. So we worry about the volume instead of the mass.
Volume is only obvious with simple builds. If you want to compare complex builds made of 2-3 different types of wire and unknown number of windings (like a clapton or flat wrapped wire) then you're quicker to just throw them on a scale than to devise some liquid displacement volume measuring apparatus.
That I know. We are talking Heat Capacity as it is referred to on Steam because you stated it is incorrect. I said it is in relation to mass, you disagreed but yet above you just said “measured per unit mass”. So the question is, is Steam correct but just giving you an answer you are not looking for, or is Steam incorrect with it’s calculations?
I understand how Steam works therefore use it to my advantage. I also understand that N80 has a higher mass than Kanthal for the same volume in which it’s Heat Capacity will be reflected as such. If Heat Capacity is my only objective with building a coil, I will adjust the coils dimensions to reach that goal. If I want to use 24awg N80 but keep my Heat Capacity under 75mj/k, then Steam tells me I must use 7 wraps or less for a 3mm ID coil. But Heat Capacity is not the only perimeter I refer to when building a coil.
So what is the Volumetric Heat Capacity of Kanthal vs N80 for the same dimension coil? Provide an example so we can compare to what Steam gives us to see if this can be used to our advantage. Maybe even drop the developer a note and explain it's importance.
To me coil building is not always about comparing apples to apples in the forum of volume or the same coil dimensions. It is about trying to achieve a happy medium for there will always be a compromise.
What do you mean? Steam calculates the volume automatically for you.
I'm not using steamengine to build my coils
so I was talking strictly from a hands on computer off kind of approach.Nice feature though, might come in handy one day.
Mainly use Steam to link newbie coil builders to it because it answers most of their questions.
Heat capacity, also known as specific heat, of the metal type is measured per unit mass. Volumetric heat capacity (VHC) of the metal type is measured per unit volume. The VHC of the metal type equals heat capacity of the metal type multiplied by density of the metal type. The VHC multiplied by the volume of the coil is the heat capacity of the coil, not to be confused with the heat capacity of the metal type. The heat capacity that Steam reports is the heat capacity of the actual coil, not the heat capacity of the metal type. So this is what's gotten you confused. But anyway... the numbers that it reports are suggesting a Kanthal A1 coil heats up faster, watt for watt, than the exact same coil made from either Nichrome 80 or SS 316L. Which everyone familiar with coil building already knows just can't be right.
I never said heat capacity should be your only objective with coil building. Just that Steam is wrong about something, and, apparently, it wouldn't be the first time, either...
Heat capacity, also known as specific heat, of the metal type is measured per unit mass. Volumetric heat capacity (VHC) of the metal type is measured per unit volume. The VHC of the metal type equals heat capacity of the metal type multiplied by density of the metal type. The VHC multiplied by the volume of the coil is the heat capacity of the coil, not to be confused with the heat capacity of the metal type. The heat capacity that Steam reports is the heat capacity of the actual coil, not the heat capacity of the metal type. So this is what's gotten you confused. But anyway... the numbers that it reports are suggesting a Kanthal A1 coil heats up faster, watt for watt, than the exact same coil made from either Nichrome 80 or SS 316L. Which everyone familiar with coil building already knows just can't be right.
I never said heat capacity should be your only objective with coil building. Just that Steam is wrong about something, and, apparently, it wouldn't be the first time, either...
If Steam is incorrect then prove it. I’ve asked for examples twice now. Won’t dispute your claims but without objective data it is nothing more than a subjective theory.
As a matter of fact it's already proven itself wrong, basically (except of course if you don't already know the very basics about coil building, as that also includes knowledge of the fact Kanthal A1 does heat up slowest, watt for watt). All you need to do to figure this one out is look at the heat capacity number that it reports for Kanthal A1, and then compare that to the heat capacity number that it reports for either Nichrome 80 or SS316L, i.e. without even changing any of the other parameters it just obviously goofs, right off the bat.
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