im having troubles wrapping my head around so much, if anyone has any knowledge at all i would love to pick your brain. Taking up a new trade and failing hard, please help me lol.

For fg, yes

Lol, worm.

Go ahead and poke away, I have some knowledge of the trade.

Google

thanks,i'm almost an entire year into my course, already a licenced gas fitter, but google will solve everything.



e: I've been scouring google for a year in case you missed the sarcasm.

This post was edited by dude_927 on Jun 18 2015 04:19pm

actual question?

How does enthalpy work? what is superheat? How do i know which odp to use? How does work force work? Why is VA a useful rating? How does refrigerant change state and where in a residential system? (plenty more if needed)

Simplistic view,

Enthalpy is basically numerically describing how much heat is added or lost (that being thermal energy basically) + the work done by the change in volume of that gas/liquid/or even solid (more physical).
A gas in a jar can gain or loose heat, and at the same time expand or compress. So there are 2 components of possible work. H = U + P*V @ constant pressure

Superheat is basically when the gas has extra heat energy. You usually superheat something because you don't want that gas to condense back to liquid when it touches something.You want that gas to stay as gas. Superheated gas is able to loose some energy and still be in the gas phase.

I don't know what odp is.

Work force work? I'm not sure I quite understand the question

I don't know what VA is.

How does refrigerant change state? home heat pump system

http://www.daviddarling.info/images/heat_pump.gif
let's start at the compressor,
The compressor compresses the gas phase refrigerant (gas),
that moves into the condenser (outside of the house) where it is cooled by the outside air to liquid phase.
The liquid phase then goes through a expansion value where it turns into basically gas phase again -> compressor.

This post was edited by saber_x3 on Jun 20 2015 01:37am

so what exactly am i calculating and how does it relatre to that chart i posted earlier?

i still don't exactly understand superheat, i'm supposed to look for 8-12 degrees farenheight of superheat, what exactly am i looking for and what does it mean?

ya i dont understand this one at all lol, ill come back monday with a more coherent question about it.

VA is the volt amp rating of a transformer, but voltage and amperage are presumably intermingled anyway (although i dont quite understand the relationship as it goes through a transformer, i was assuming it had something to do with that)

ya i've been staring blankly at a similar chart for a few weeks now, im supposed to be able to identify "high/low pressure/temp liquid/vapour" throughout and even memorizing a chart of that isnt helpful if i don't understand whats actually happening.

e: wow that was actually simpler than i had it setup in my mind, stupid question, where does the cold come from?

This post was edited by dude_927 on Jun 20 2015 01:49am

Well, with that chart you can basically look up how much energy that refrigerant has at a given temperature/pressure/phase
By measuring it at 2 points in your system, you could calculate the amount of work (cooling or heating) your system does.


8 degrees of superheat means your gas is 8 degrees above its boiling point. Think of boiling water, does that steam not turn into water when it touches something? If you were to heat the steam above 212F, itd have to cool back down to 212F then turn back into water.

O, a Voltage amp rating.. gives you basically a voltage and amperage rating.
Given that rating you can calculate fuses, possible size of load, etc