Regarding how to size a unit via model number for tonage, cooling?

Hello all! I am a "field trained" technician who started as an apprentice and after being deployed for 5 years and out of the business, and becoming wounded rotating home am back in the service industry. I have been working on my own with the aid of my retention and a few books I bought,charging tables ect. but am wondering how to do what I used to know how to do but forgot after being out for so long. I remember that you can tell the current size of the unit (tonage wise) by looking at the model number. What exactly am I looking for in that number that tells me the units cooling tonage? I remember doing this all the time but like I said I've been out and disabled for five years and despite my ability to retain for some reason cannot remember this one?! I think it is important to know that I am an honest tech that does not sell people things they do not need.I dont condemn compressors to get the install, nor do I tell someone there leaking unit is from low charge when it was really from a dirty filter and coil...I clean the coil and change the filter...then if needed will charge the system. I see alot of this "fake diognosis" and it bothers me because it really creates a distrust of every HVAC tech out there.I also volunteer to help low income folks by charging systems replacing say a relay, or safety to restore their cooling at no charge, only donations in the way of bid/barter...I live in a warm place and without AC people really do suffer.
On a side note, I have been doing pretty good with not one "call back", retained alot from five to six yrs ago, in fact in many ways Im better than I was when I worked for someone else, I offer prompt service, great prices, have my universal and license for refrig. products, have installed three splits but they were exact replacements. I want to know how to use the model number to obtain the tonage of cooling for an existing unit. Just so anyone who reads this, unlike many "techs" in my area I do purge the system with nitrogen I do use 3 psig while brazing, I do still use a sling psychrometer,sub cooling,superheat, ohms & watts law,ect in my daily service. Any resources regarding this question about the model # / tonage and ANY other training materials would be very welcomed so I can provide the best service possible. Many thanks....Ian
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wrote:

That's a nice long story you've got there Ian. As usual, Im quite critical but I gotta tell you. You know all you've said but you cant tell btu size by the model number??? That makes your story totally strange. Id give it up to someone that can handle it. Bubba
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Thank You for your service and your sacrifice. Hope you're healing well.
As far as the model #s and stats, they vary amongst the different mfr's. As you know 12, 18, 24, 36, 42, 48, 60...etc frequently represent tonnage of the equipment. The answer is however not that simple. Different indoor and outdoor coils sizes will determine system capacities. If in need to identify a unknown unit you can find the model number on the compressor. This will tell you the design capacity of the compressor in btus i.e. 24, 34, 46...etc Experience and making good contacts with the mfg's and distributors will be very helpful. Also a few of the guys here are great sources of info for specific brands.
Joseph
p.s. Do not listen to the Stormin Moron as he is the worst hack around...
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I learned that one on day two of my apprenticeship, However I still don't know how brain dead one moron can be. FYI pus-brain, the sad thing is that you don't know most units will have the tonnage discernable in the model number not the serial number. Grainger keeps in touch with me and I have the Rep's cell#, Dickhead. I also don't buy my HVAC equip from Grainger's , I prefer Trane and Bryant (Carrier if I must) and I have their direct lines as well. If you were to ever get a clue, there would be no one hear to know it, as we'd all die of shock...
Can you get your hands on a standard red clay brick? If not I'll send you one...
BY-the-way, on day one of my apprenticeship, I learned to STFU when I don't know what the fuck I am talking about!!!
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ditto'd this comment

One piece air handler, downflow, painted, flowrater, tonage, stormy's IQ

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Seems like Stormy doesn't want to answer the question.... LOL
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wrote:

over 4 is being too generous. Bubba
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