AC question

[Cougsfan]

One comment I will make concerning his no repaired dilemma and that is, in post 33 with the view of the roof mount ac components, there is a substantial amount of dirt and chaff on the blower housings and as such, I suspect there is also quite a bit under the evap / heater core cover as well on both HX's and that will reduced the efficiency of them in both heat and cool modes.

You do make a point. I pulled the cover off my evaporator/ heater cores and cleaned them as one of my steps. It is a difficult chore on my tractor. There was substantial amount of dirt on the leading edge of the evaporator. I cleaned it off and I could notice a difference in air flow. However at that point in my project, I had no freon flowing, so the air temperature off the coil was the same (warm) before and after cleaning. I did read last night that if the air flow is decreased via dirt on coils what you will likely see is a drop in the air temperature because the same amount "negative" btu's from the freon evaporating has a smaller volume of air to cool. So it cools it further. Likewise, when you turn your cabin fan to a faster setting, the air temperature off the coils might actually rise, but despite that the cooling of the cab increases because of the increase total amount of heat transfer that occurs. Makes sense.

 

[Cougsfan]

Entirely false. AN is an inhalation hazard causing death and it has to be incorporated (as in knifed in below the ground surface). it is not 'spread' like granular fertilizer. IOW, you get as good whiff of AN, you are toast.

In my early work career as a food processing plant engineer I was more than once around very serious leaks in anhydrous ammonia refrigeration systems. We didn't have any personal protection other than googles, a condition that would require hazmat suits these days. I have seen the air so green from ammonia that you couldn't see across the room, It was definitely a situation requiring concern and caution, but not "that" big of a deal back then. What will happen is your eyes, arm pits, crotch and nose will burn to high ****. The burning will be what gets to you and eventually causes you to dash to fresh air, not poisoning via inhalation. I have gotten far more than a "good whiff" more than once. Here, 40 years later, I am not yet toast. What the experienced refrigeration operator would do is have people man water hoses and spray water all over the place to change it to aqua ammonia. It still stank and burned, but it allowed you to fix or isolate the leak. These days, rightfully so, you can't approach an ammonia leak in the same manner we used to. It can be explosive. I suppose if you were locked in a room of anhydrous ammonia it might asphyxiate you, but so would any freon. Any experienced refrigeration operator will tell you a freon system is more dangerous than an ammonia system because of the risk of asphyxiation. There are a lot of exaggerations floating around concerning how deadly ammonia is.

I have never been around using anhydrous ammonia as fertilizer, but I am quite sure you won't ever be exposed to the same conditions and concentrations as a leak in a enclosed ammonia refrigeration compressor room.

So before you accuse someone from not knowing crap from applebutter, you should be sure that you know the difference yourself. Of course you have the right to say whatever you want on a public forum. But why do feel that gives you the license to be rude? I don't get it.

 

[aczlan]

In my early work career as a food processing plant engineer I was more than once around very serious leaks in anhydrous ammonia refrigeration systems. We didn't have any personal protection other than googles, a condition that would require hazmat suits these days. I have seen the air so green from ammonia that you couldn't see across the room, It was definitely a situation requiring concern and caution, but not "that" big of a deal back then. What will happen is your eyes, arm pits, crotch and nose will burn to high ****. The burning will be what gets to you and eventually causes you to dash to fresh air, not poisoning via inhalation. I have gotten far more than a "good whiff" more than once. Here, 40 years later, I am not yet toast. What the experienced refrigeration operator would do is have people man water hoses and spray water all over the place to change it to aqua ammonia. It still stank and burned, but it allowed you to fix or isolate the leak. These days, rightfully so, you can't approach an ammonia leak in the same manner we used to. It can be explosive. I suppose if you were locked in a room of anhydrous ammonia it might asphyxiate you, but so would any freon. Any experienced refrigeration operator will tell you a freon system is more dangerous than an ammonia system because of the risk of asphyxiation. There are a lot of exaggerations floating around concerning how deadly ammonia is.

I have never been around using anhydrous ammonia as fertilizer, but I am quite sure you won't ever be exposed to the same conditions and concentrations as a leak in a enclosed ammonia refrigeration compressor room.

So before you accuse someone from not knowing crap from applebutter, you should be sure that you know the difference yourself. Of course you have the right to say whatever you want on a public forum. But why do feel that gives you the license to be rude? I don't get it.

That matches what we are currently being taught for dealing with anhydrous ammonia at work.
We had a live release training last year and (unsuited), we were within a couple hundred feet.
The guys and gals who were suited up (level A hazmat suits with SCBA) went up to it and tarped the "release" point, then shut off the valve.
Is it to be respected? Certainly.
Is it to be feared? Not so much.

Aaron Z

 

[LouNY]

That matches what we are currently being taught for dealing with anhydrous ammonia at work.
We had a live release training last year and (unsuited), we were within a couple hundred feet.
The guys and gals who were suited up (level A hazmat suits with SCBA) went up to it and tarped the "release" point, then shut off the valve.
Is it to be respected? Certainly.
Is it to be feared? Not so much.

Aaron Z

The times sure are a changing, wasn't too many years ago that a water fog was the prescribed method of dealing with a great many gaseous releases and many liquid spills.
Nothing like walking into a spill or release in street cloth and a rain suit with a respirator or many be an SCBA, or working in hazardous level of a product with a hose connected breathing mask (H2S) so much fun. And yet somehow we survived and got the job done.

 

[aczlan]

The times sure are a changing, wasn't too many years ago that a water fog was the prescribed method of dealing with a great many gaseous releases and many liquid spills.
Nothing like walking into a spill or release in street cloth and a rain suit with a respirator or many be an SCBA, or working in hazardous level of a product with a hose connected breathing mask (H2S) so much fun. And yet somehow we survived and got the job done.

Water fog is still prescribed for knocking down Ammonia clouds, we had it on hand for our live release training, but we decontaminated the hazmat suits with large fans until they didn't change litmus paper, less mess and cleanup for the Level A suits than hosing them down.
Code requires much more ventilation (especially in mechanical spaces) now than they used to even a few years ago.


Aaron Z

 

[Cougsfan]

They have changed so many things when it comes to using ammonia as a industrial refrigerant starting in the mid 90's, all for the better. Having ammonia monitors and alarms are now the standard. Better ventilation in rooms that may contain ammonia, better isolation capabilities. PPE that is readily available for use, clear established operating procedures, mandatory training to deal with a problem, mandatory spill reporting, mandatory locks on systems to keep people from robbing it to make meth (we have had that happen) etc. Most companies went through a thorough review of their particular systems and developed their own emergency response procedures. Some may claim it is going overboard, but not really. It is just being responsible. And yes water is still used to knock down ammonia.

The same kind of protocols are used for other refrigerants too, it just isn't ammonia.

Another side note, back in the day I'd walk into an ammonia compressor room and smell ammonia. I'd ask the refrigeration operator why am I smelling ammonia. A common reply would be "I don't smell anything." People who are around it all the time become desensitized and it really has to be fairly strong before they can smell it. Sort of like the people who live around a pulp mill. After a while they don't even notice the smell.

It is sooo nice to have an AC in my tractor again!