hi, if head pressure goes up to 350 and suction pressure stays at 100 in your example. would MORE refrigerant be fed into the evaporator because of bigger pressure difference? thanks.
I have a mismatched 1995 Bryant 10 SEER coil and a 2015 Trane 13 SEER condensing unit MOD # 2TTB 3048A 1000 NA 4T R22. The orifice doesn't let enough refrigerant through under heavy loads and I would like to change it to a TXV. Do you have any recommendations on size or model number? Do you think an external equalizer is necessary? Do I need one that will bleed off the pressure during the off cycle? Thanks.
The system will never match properly. To answer your questions, size is 4 ton. external equalizer is necessary. You may need either a hard start kit or a bleed TXV. GFM
Question: If you needed to open the system for some reason, add dryer or pull the evaporator or...... Could you close the outlet on the compressor and suck the system down with the compressor and them close the suction side and open the system? First would this be legal and 2 how low would you suck the system down to. I remember seeing a tech do this many years ago when he started a system and found a leak. How would this be done legally if it can be done. Thanks for your time.
amtpdb1 You can pump the system down if it has valves on the condensing unit. Here is a video on how. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-qBTHLHh3394.html This, of course is only useful for working from the liquid line out of the condensing unit and beck thru the suction line to the outdoor unit. When the repairs are done the portion of the system you have worked on must be evacuated using a vacuum pump before opening the valves and putting the system back in operation. Because you are not dumping refrigerant to the atmosphere, there are no laws violated that I know of. Hope this helps. GFM
Say you bought a new condenser and evap coil. the evap coil has that orfice installed, and there is one in a baggie hanging off the condenser. Which one should i use?
Pretty much. low suction, low head, low delta T, adding charge makes no difference, Usually that is the problem. Other possibility is plugged drier (should be a temp diff across the drier). Subcool should go up as charge is added but no corresponding rise in suction pressure. hope this helps. GFM
Hi, I'm working in my home ac, after l lost all my freon r22 due to a leak in the outside condenser, I'm looking to recharge with a compatible and eco friendly freon. I watched your video and went and look the evaporator and came across with txv valve with 2 check valves, before and after the txv and it has orifice piston #40. It's a 2.5 ton Rheem unit with a 3 ton out side condenser. does it need all these components? or can l keep just the orifice piston and remove the txv?, btw, the txv has a equalizer as well. Thank you
Hi GFM. I'm helping out a friend whose evap coil is leaking. It is a superior coil which isn't being manufactured anymore. The old coil was 3.5 tons and the cond. is 3 tons. I put in an Armstrong 3.5 ton coil. The problem I have is I cannot find anything on the condenser as to what size piston to use. Do you have any piston charts or any suggestions for the best size piston. My research on line is leading me the conclusion that I should use a #73 piston. It is an r22 system. It would have probably been best to replace the whole system but money is tight as his wife is recovering from cancer treatments. Thanks for your help.
+johnmiller102 I do not have any charts. About all you can do is use target superheat for charging and change pistons if necessary. Hope this helps. GFM
Ok. Thanks. Would it be correct that if superheat is too low and the system is charged correctly than the piston is too large? If too high than the piston is too small? My concern is if the piston is too large I might end up slugging the compressor.
I have a question on how one would select a specific size orifice.....I have a 2.5 ton Rheem r-22 condenser that was hooked to a York slab evaporator that employed a #59 orifice......I am replacing the slab coil with either a 2.5 or 3 ton "A" coil (depending on what I can find locally) ---wondering how I determine what size orifice to use with the new coil....dont really want to go to TXV - its a 10 SEER unit and dont see the benefit of TXV here. Any info or place you can send me much appreciated - will be doing this soon since system is down from evap leak and its hot here
I have a unit that has 3 pounds of freon. No leak. Evap is freezing up.. if I over charge the unit.. low side remains in fessing temperatures...air flow is good. Should I question the fixed orifice or the compressor?