[yuri]

True story of an electrical problem that can kill someone. Read post below about hissing sound.
http://www.diychatroom.com/f17/noise-carlyle-compressor-hissing-sound-40239/

 

[hvaclover]

The amount of phosgene generated by R22 (an HCFC ) vs say R12 (a CFC)
is minuscule by comparison.
The reason being a Halogenated Chloral Floural Carbon has about one atom of chlorine vs many atoms in a Chloral Floural Carbon.

And the amount of phosgene that is produced has been studied and the final determination was that all though some little amount of phosgne is produced
it does no where near the lung damage a weaponized dosage would do.
The study was published in RSES monthly magazine about ten years ago.

CFCs(R12, R502-ect-) produce volumes more of phosegene is the presence of flame than R22--an HCFC--.

When a compressor loses its charge due to a failed fusite, the reason is due to a badly contaminated system that has turned to acid . when a cloude of contaminated refrigerant is released it is more likely to be acidic
than have a large amount of phosegene because there is no sustained flame to burn the gas. The fusite blows the breaker will trip and eliminate any possibility of a heat source to caytalize phosgene.

Breathe the vapors of the the escaped R22 vapors you would be ingesting burnt oil, acid, and other irritants that can cause Upper Respiratory irritation and shortness of breathe.

Been there my self on more occasions than I care to admit.

 

[yuri]

I have smelled phosgene from the old days when we used halide leak torches and yes I did refrigeration/R12 work. When this bugger blew my customer was nearby and it smelled like acid/phosgene and I was in no mood to analyze it. Sure glad I never went thru WW1 like my Grandpa did. They used mustard gas/chlorine/phosgene and any other nasty chemical they could find on each other.

 

[hvaclover]

i think al us seasoned pros know the Mustard Gas analogy. And the gents that wrote the first paper on R12 when it was invented back in the early first half of the 20th century were vets of WWI. As a result the "mustard gas" horror story was given more emphasis than it actually deserved. And like any good story it got pumped up out of proportion compared to it's real world toxicity.

The next new urban legend is going to be the the Hygroscopic nature of R410A and the proper way to handle and install it.

A few mfgs are really pumping more mis-information into their 410 A training that only serves to make a lot of contractors hold off on suggesting 410A systems over R22 system to new equipment buyers. The amount of 410A hold outs are more than 60% according to a recent HVAC News poll.

The main reason stated was the unfriendly nature of the refrigerant and it's dangerous high pressure.

There's always going to be urban legends in this business that have their roots in fact but fear off their application based on misinformation or plain bad training.

 

[yuri]

I am REALLY interested in seeing if all the horror scenarios of a bit of moisture in these R410 units are going to destroy them. Lets face it, I doubt if 10% of the techs have the time/training/proper vacuum pumps or even care to pull a 500 micron vacuum.

 

[kenmac]

You guys ever worked on any ammonia charged N.G. a/c units ?? Talking about something that will take your breath away !! Most if not all of these units that I use to service are gone due to the EPA regulations. I sure am glad to see them gone

 

[yuri]

I smelled a bit of 100% pure ammonia once at trade school. A newbie accidentally cut a line on a demo unit. I would NEVER work on that stuff. It sucks all the moisture from your lungs/eyes/skin and is deadly.

 

[hvaclover]

You guys ever worked on any ammonia charged N.G. a/c units ?? Talking about something that will take your breath away !! Most if not all of these units that I use to service are gone due to the EPA regulations. I sure am glad to see them gone

They are still around. EPA does not have a ban or regulation against these units because the chemical solution they use.


Gas-Fired Air Conditioning Equipment For Residential, Commercial & Industrial Applications

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Advantages of Natural Gas Air Conditioning

Natural gas air conditioning offers these important advantages:​

• Efficient and economical – reduces energy use 30% to 50% compared to electric air conditioning and quickly pays for itself
• Multiple zone comfort control
• Minimal ductwork – adaptable to baseboard heating
• Sealed refrigerant – no leaks, no loss of efficiency, no “re-charging”
• Environmentally friendly ammonia/water absorption process
• Low maintenance -- no compressors and few moving parts
• Long life – up to 2 to 3 times longer than conventional electric systems
• Safe, quiet operation

​

 

[hvaclover]

I smelled a bit of 100% pure ammonia once at trade school. A newbie accidentally cut a line on a demo unit. I would NEVER work on that stuff. It sucks all the moisture from your lungs/eyes/skin and is deadly.

I did Ammonia when I first started out. Didn't do it too long.

You think R410A Polyolester oil absorbs water!

 

[kenmac]

I don't know about the newer ones. When I had to change out generators on the older units . there was no way to recover the ammonia. what my lungs didn't absorb went on the ground.Talk about a total vegetation killer !

 

[hvaclover]

I don't know about the newer ones. When I had to change out generators on the older units . there was no way to recover the ammonia. what my lungs didn't absorb went on the ground.Talk about a total vegetation killer !

You don't blow R717 into the air. There were liquid pumps for evacuating the systems in my day as well as today.