500 microns? - then you are a HACK!!

[Dr. Hardcrab]

JEEBUS CHRIST ON A CRACKER!!!!!!

This damn place is turning into alt.hvac........

[Richard J Kinch]

It will not vaporize without the addition of heat.

It will not vaporize if it is bound to another substance.

[JohnR66]

It is. Check the cross posting...

[bill]

You aren't the only one who works on low temp refrigeration.

You can't spew bullshit and not be called on it. Cite your sources dildo. Or STFU. There. You've been called on it. Pony up or pussy out.

[Jake]

Sam,

I think Dido is talking about when you have a evap coil exposed to other cold temps within a running freezer.. a common occurence in the commercial world.

This is what the man meant, I believe.

Jake

[chip]

don't new a/c installs have to be evacuated to 300 microns? in automotive we use 600 microns, but we also use 0-rings instead of sweated fittings. I'd really like to see the vaccuum pump that will pull it to 50 microns. Chip

[Dr. Hardcrab]

DUH!

(I missed that)

[Jake]

OK, I buy that! The info in your article also said "If you've got a week" or something similar. I don't think a tech in the field has that kind of time, so perhaps that's what Dido is addressing.

I've seen ice develop in commercial Vacuum systems, and it does not dissipate easily... it takes a long and slow pull. (NO one please make a inference from this given my comments below)...

I *do* understand the pressure relationship, believe it or not....

BTW, I think I was either drunk or high in 9th grade science class...or perhaps making passes at the lovely 'Tracey' that sat next to me, as I recall. Tracey ended up on crack or welfare, or both, I think...

Oh, I got an A in Science... maybe it was Math, or English... or something (-;.....

ahhhh... the '70's. DON'T TRY THIS NOW, KIDS!

Jake

[nicksanspam]

Learn something new every day around here.

Nick

[papaya]

" in automotive we use 600 microns"

EXCUSE ME???

WHAT KIND OF BULLSHIT "MECHANIC" ARE YOU??

I am in automotive A/C, and we use 50-75 microns vacuum, if you use 600 then you are screwing your customers, and blaming O-rings for your insufficient vacuum is ridiculous, what the hell do you think the seals your manifold gauge set, hoses, and all other equipment are made up of?

you need to be in the special olympics, rather than working on automotive A/C, you stupid retard hack

[DiDo]

No I am not you are absulutly right Good luck Dido

[bill]

So you're going to pussy out I take it?

[PrecisionMachinisT]

Ignore the entire concept of latent heat if its convenient to you then....

Point being is the heat was already added or subtrcated from the sytstem before or after the phase change took place........still, its pressure causing the actual change to occur.

Im done, your a f****it and my opinion still stands.

And I've heard that it's f****ng hotter than hell out there, too...

[Richard J Kinch]

Dessicants, lubricants, contaminants. They will not release water of hydration just because you apply a vacuum at ambient temperatures. Neither will slugs of free water trapped in lines, without either a lot of time or an external heating source.

Only in proportion to the heat added. It *will not* sublime at all if there is no heat added, even in a perfect vacuum.

The universe is full of solid water in the near-perfect vacuum of space. Comets are an example.

Commercial food freeze-drying apparatus provide a circulating heat medium on the trays. You can't just shove hunks of wet food in a vacuum chamber and pump it down to freeze-dry it, practically speaking. Neither can you dry out a wet HVAC system by leaving it on a vacuum. I know this is an article of faith in the HVAC trade, but it is a myth beacuse the tradesmen only learn a shallow smattering of chemistry and thermodynamics. And they just want to believe it.

[Richard J Kinch]

Repeat after me: temperature is not heat.

[PrecisionMachinisT]

Obviously then , some part of "Im done, your a f****it and my opinion still stands" has apparently still escaped your attention.

Bye bye idiot troll.........

[gfretwell]

I am not sure where you live but it is about 600 degrees F warmer than "space " on earth, even in the winter. There is plenty of available heat to sublimate water.

[Joshua Putnam]

In case this was a genuine question, one micron = 1/25,400 inch.

In the case of vacuums, that's inches of mercury, just like in a barometer.

[Stormin Mormon]

Ah, an excellent question. A micron is a stone that is mined in South Africa.

[Richard J Kinch]

Haven't ignored anything.

(Regardless, I suspect you mean sensible heat.)

The heat initially present in the water itself, or something intimately in contact with it, will vaporize very little water, and in practice the ambient heat will not flow in quickly (the vacuum being an insulator).

And this only applies to free water. Ordinary vacuum dessication does not work for water bound in something like a silica gel dessicant, or entrained in the oil, or hydrating contaminants.

A lot of people have been taught the pseudo-scientific myth that "water boils in a vacuum" in some magic sense that it doesn't in the atmosphere. The truth is that water vaporizes in a vacuum or in the atmosphere the same way: *only* because you add heat. In the same sense, water doesn't boil at 212 deg F, it boils because you add more heat after it is at 212 deg F.

Another related myth is that if *you* were put into a vacuum, your body would explode or your "blood would boil". Pure bunk.

Another popular (and yes, even in the HVAC trade) myth is "saturation" of air with humidity, that the moisture is carried or dissolved in the air, and that it "saturates" like a solution of salt in water.