Tweet
Welcome Back P-R... Very glad to read the good news and congratulations, Brother! 
IMPORTANT EDIT:
What makes you think your compressor has gone bad? If your condensing unit compressor is of the SCROLL variety... unless it was allowed to run without any oil at all,,,they are almost failure-proof because as they get used...they tend to wear IN rather than OUT like the old, hermetically sealed piston compressors tended to do. The reason I ask is that most and I do mean about 98% of HVAC problems turn out to be electrical in nature with either blown 240/24 transformers or failures in High or Low pressure sensitive valves or involving the Definite Purpose Relays that use 24 VDC signalling coming from the House Thermostat to govern the "bulkier" flow of the more powerful 240 VAC circuit. In the case of your outside condenser unit, it might be that your large air fan used to pull heat out of the returning superheated refrigerant to "condense" it back into a liquid has failed and a simple fan motor and careful propeller blade replacement will do the trick. Most of the tests needed to check each and every electrical component in your system are available to watch and learn from on YouTube with a simple search on the term "HVAC" and "ELECTRICAL" to reveal them all...some of these will show you where to look and how to safely test the system WITH THE POWER BREAKER OFF! and find the problem components using just a basic multimeter to find things out.
Okay... But if worse comes to worse and the compressor has died an unnatural death, after un-brazing the lines and getting it out of the way... get a basic HVAC Flush System and purge all the old, burnt out oils and debris from the system line set after the pull down and vacuum of the unit. The first thing I want to let you know about is that the tools that go along with this project are NOT cheap and are not sold in any places other than either HVAC dealerships (or on eBay) , all of whom will stare you down if you do not possess the required EPA 608-609 Licenses. Remember that they mostly sell to larger outfits that buy and service complete systems rather than selling small bits and pieces of equipment to "The Great Unwashed" of our ilk. But you know me... I can be be very resourceful and have proven so in this matter already... and without saying much more.. .just look at the image attached and pay particular attention to the eBay vendor name... Just remember to lurk on the item you want to get and stay alert until the very last few minutes... and OVERBID THE LAST BID YOU CAN SEE BY UP TO FOUR TIMES THAT VALUE... Don't worry...you will not have to pay that amount unless someone else can beat your bid in less than a one minute left of bidding time.... and YOU WILL WIN THE ITEM AT $1.00 MORE THAN THE NEXT LOWEST BIDDER. I mean really...look at what the winning price for the stuff was in the attached image...and realize that this stuff sells for up to $40.00 a pound now...and will not be available after 2012...!!! Okay... THAT IS YOUR BEST OPTION!!!! With no other "Legal Entanglements" so to speak!
This guy "Dr. Z" has many of the BEST HVAC REPAIR INSTRUCTIONAL VIDEOS ON THE NET and he is a down-to-earth instructor who won't overload you with theory and garbage while just doing the repairs! Prime yourself with as many of his videos as possible and the learning curve will flatten right out. This is one video on how to R&R an outside compressor... please search YouTube for many others to get a better look at how this is done.
As for the tools... Here is the Bare Minimum...
1. Oxy-Acetylene Torch Set (I used a size 20 O2 Tank as the oxidizer and Propane and MAPP Gas and it worked fine as the fuel...they make a very nice and hot Blue Flame together!)
2. Dry Nitrogen WITH A PROPER NITROGEN HIGH AND LOW SIDE GAUGE MANIFOLD!!!! You can easily blow your system or yourself up with this stuff if not used properly!!! Use this stuff to very gently break the vacuum first purge your lines after pulling down a long vacuum session to remove all the old moisture and non-condensable gases in the line. Then use around 3 PSI of Nitrogen to pressurize the cleaned lines while brazing your fittings to prevent awful scaling inside and risking damage to your new compressor. After your system is completely sealed with new brazing(s)... vacuum down the system for at least an hour and then pressurize to 150 PSI with the Dry Nitrogen and then check your brazing points with green sticky "Predator Blood" HVAC Line goo to make certain your welds do not leak. Relieve the high pressure at 150 PSI before attempting any brazing on found leaks. Its best to use a mirror and flash light to examine your brazing points carefully. If the system holds a Nitrogen charge at 150 PSI for over an hour and the High and Low Gauges show no drop in pressure... then you will have succeeded! Very Slowly (to prevent purging Compressor Oil) Release the High Pressure at 150 PSI though your Manifold Gauge set...without letting in ambient air...and then pull another serious vacuum down to about 25 microns (CORRECTION: 500 Microns). (A Micron Gauge is expensive ...but definitive in proving how good a vacuum you manage to attain). Get a good idea of what valves to open and close on your gauges so that you don't wind up contaminating your new lines and compressor with atmospheric air accidentally ...or vent freon for the same reason. This process requires close attention to what is happening while charging or discharging this closed system at all times.
3. R-22 Manifold Gauge set to read your system High and Low Side Pressures when charging and testing the system for leaks and leak downs.
4. SilFos Silver/Copper Brazing Solder...strong and secure brazing with not too high temps to risk burning holes in your copper piping.
5. Copper Swaging Pin Set in case you need to splice any lines with lengths of new piping.
6. Fine Cloth Abrasive "Sandpaper" to clean your fittings bright and shiny and pristine clean (wipe everything off of any grit inside and out!)
7. A New Pipe Cutter to cut lengths of HVAC Copper Tubing.
8. NEW HVAC Copper Fittings and Lines... NOT standard plumbing copper pipe! in either 3/8" OD for any liquid line replacement or 7/8" or 3/4" for your vapor line replacements.
9. In order NOT to lose the existing refrigerant in your system, you will need a special HVAC Recovery Pumping and Evacuation System to salvage the R-22... God forbid it to preserve the Ozone Layer of our Earth... but sometimes accidental discharges do occur... if the old freon leaks out...you will need some more new R-22) If you can access a recovery machine...you will require an appropriate Yellow/Grey container to store the refrigerant and these can cost around $100 for a 30 Pound Recovery tank. Let me know if you will be doing this procedure and I'll provide more instructions on how it is safely done. NEVER ATTEMPT TO RECOVER REFRIGERANT IN A GREEN R-22 DISPENSING CYLINDER!!! People have been killed over-pressurizing these tanks and turning them into Freon Bombs!!
10. HVAC Refrigerant Scale... CPS Digital Model CC220. This Item is a MUST and will make your life a "Breeze with the Freeze" with re-charging the system!... because once you know how much refrigerant was originally in your system... LISTED ON THE COMPRESSOR UNIT... then you can easily and precisely WEIGH IN A NEW R-22 CHARGE (just REMEMBER TO add .6 Oz for each additional foot of 3/8" Liquid Line running from your outside compressor unit up into your air handler evaporator. The digital readout on the scale can very accurately measure pounds and ounces of coolant down to 100th part of an ounce! You must first break the vacuum on the system after light purging the lines of your R22 Manifold Gauge Set and hooking up all your lines with NO AIR in them! This is doen with the R-22 Cylinder in the upright or "Vapor Position" Then the green cylinder is inverted and set upon the freon scale after being zeroed out and weighed for its present weight. Write that number down and after checking the necessary weigh-in charge you need from the aluminum product plate mounted on your outside condenser (plus the .6 Oz. for each additional foot of liquid line running between your outside condenser unit up into your attic air handler evaporator) you simply have to use basic arithmetic to subtract the charge weight of what you need to put into your system from the present total weight of the green cylinder and note how much the green can should weigh once the full charge is installed and write down THAT number, Zero your scale and then place the green can upside down on it and plug in your 220-240 VAC Circuit Breaker and have somebody go in the house and turn on the thermostat to "COOL" and lower the setting to around 72 Degrees. If the compressor does not immediately turn on, shut off the system by pulling the circuit breaker again and weigh in about half of the needed charge via the Manifold Gauge Set LOW (VAPOR) SIDE ONLY! Close all other valves on the gauge set, especially the one Red Line for the HIGH Side liquid line. Then simply slowly open the charging valve on the green cylinder and then very slowly crack open the LOW SIDE vapor valve on your manifold gauge set to allow the liquid freon to enter the system. When you have weighed in about half of the required weigh-in charge... plug the circuit breaker back in and have your "helper" turn of thermostat to "COOL" and lower the temp down to 72 Degrees F. The new compressor should kick on and you can then you can open the LOW SIDE valve on the manifold gauge again and continue to very slowly allow the liquid freon into the low side of the system. Please remember to use only the BLUE side to do the freon charge hooked up to the larger vapor line and NOT the smaller liquid line...and so this slowly because you don't want to "SLUG" the compressor with pure liquid coming in too fast from the Low Pressure Side. After a while, the internal system pressure will normalize before you have completed the charge and the you will need to turn the green cylinder right side up to finish charging the system with the remaining weight with VAPOR only. Sometimes ...having a low heat source can help with this because by now, the lower portion of your green cylinder will be "Beer Can Cold" and condensation will be collecting around the bottom of the tank. Pros use a warming blanket to get more vapor to move from inside the tank into the HVAC unit. Don't be surprised if this takes over an hour to do this right and if you screw up the scale measurement as this is going on don't panic! Just subtract the amount of what is left inside the green tank with your starting weight and see how far along you have come. When you get to within the last pound of the process...your "Helper" should be calling your cell phone with reports on what the analog air handler vent temps are and by now...cold air should be coming out of the vents. Continue weighing in the charge slowly by controlling how much vapor is going into the LOW SIDE with precise and slow controls of the Low Side Valve on your Manifold Gauge until it reaches the exact weight needed for a full charge. Let the system run for at least fifteen minutes to stabilize and then close all the valves off...but leave everything hooked up while you go into the house to check how things feel inside. Remember...it will take a three ton unit at least 24 hours to remove all the simple and latent heat that has soaked into everything inside the house...so don't be alarmed if its not freezer room cold when you step inside your home! If things are nominal inside the house and the temperature and humidity are dropping there, go back outside and look at your gauges... for R-22 your Low Side Pressures should range between 55 and 75 PSIG for R-22 and be around 220-250 for the High Side. Of course...these pressure readings are always contingent upon atmospheric pressure and ambient heat (think of Boyles' Law here...) but if everything looks nominal and stable...close off all the valves...starting with the green tank, then the Manifold Gauges. Use a leather glove when removing the two liquid and vapor lines (Red and Blue Hoses) so you don;t get a Freon Frostbite Burn on your fingers from the escaping gases!. Get those fittings loose quickly and the immediately Brass Cap both Schrader Valves to prevent any other leaks. There will be some compressor oil inside your Manifold Gauge set that must be purged with Dry Nitrogen and then put the set inside a large plastic bag for future use. Cap off all of the lines and open female fittings with brass valve covers as well and make sure the valve on the green tank is sure and capped too. If the inside air dos not get continuously cooler and get within 3-5 degrees of the setting on your thermostat...change all of the air handler air filters and consider pulling the side panel off the air handler and using a non-acidic...non-caustic HVAC Coil Spray Cleaner to spray down your evaporator coils and then flush the unit with clean, low pressure water in a plunger style Garden Spraying Pump Unit. You should also vacuum out the condensate PVC pipe at the outside of the house to remove all the old wash outs and algae from the PVC "P" Trap and down lines to ensure your condensate pan does not get clogged and overflow into your attic. These extra steps will make it very cool and comfortable inside the home!
11. It would be nice to have a Field Piece Model HS36 Multi-Meter to be able to measure your High Side Liquid Line Sub-Cooling temps and Low Side Vapor Line Super-Heat and then just chart out your gauge pressure on a Temp/Pressure Chart for R-22... but trust me... if you add the refrigerant gradually by weight into the Low Side (NEVER IN THE HIGH SIDE!!!) and have somebody checking your AC air vents for rapidly lowering temps with some inexpensive analogue HVAC Thermometers... you will know that you are close when the Low Side Vapor Line Fitting and Service Valve close to the Outside Compressor gets to be what HVAC guys call "Beer Can Cold" as you approach the upper limit of your weighed in charge. Please...DO NOT OVERCHARGE YOUR SYSTEM!!! Having too much refrigerant will wear out your new compressor and will not make things get any colder!
12. Assuming your system uses R-22... Make certain you are using the proper compressor oil for R-22!!! The replacement compressor should have a factory charge of oil...but make certain of this.
13. A good 2.5 to 3 CFPM Vacuum pump and plenty of fresh, highly refined Vacuum Pump Oil. (About $145.00 at harborfrieght) to pull a near-perfect vacuum on your system several times before and after after the new compressor is brazed in. CHANGE THE VACUUM PUMP OIL EACH TIME B4 PULLING THE NEXT VACUUM and this will guarantee that all the non-condensable gases and water vapor and dirt are being pulled out of your system!
14. Get a an appropriate sized replacement Filter Drier canister and USE ONLY A BI-DIRECTION FILTER-DRIER IF YOUR SYSTEM IS A HEAT PUMP VS A STRAIGHT COOLING SYSTEM! In either case...REPLACE THE FILTER-DRIER WITHOUT FAIL!!!!!!!
15. You will need an Old White Cotton Tee Shirt cut up into strips to wrap around any nearby fitting manifolds on your compressor...soaked with cold water and kept wet until the brazing is complete to prevent damaging Schrader Valves. Get replacement Teflon Schrader Valve innards so you eliminate them as a possible new leak source and CAP THEM WITH BRASS SEALING STEM COVERS TO BE SURE!!!
I know I am missing some things here that may have slipped my mind...but believe me...your fix will be a piece of cake compared to what I went through! I don't think you can buy new compressor systems manufactured for R-22 any more...but you would be surprised at what you can get off of your local Craig's List and especially eBay...FOR ALL THE PARTS AND PIECES AND TOOLS NEEDED FOR THIS JOB! I'll help you along the way in every way possible to get your house cool again...
There is more to the story...and if you prefer.. you can email me your contact number here: at60dgrzbelow0@yahoo.com and I'll call you directly to help explain everything better.
IMPORTANT EDIT:
What makes you think your compressor has gone bad? If your condensing unit compressor is of the SCROLL variety... unless it was allowed to run without any oil at all,,,they are almost failure-proof because as they get used...they tend to wear IN rather than OUT like the old, hermetically sealed piston compressors tended to do. The reason I ask is that most and I do mean about 98% of HVAC problems turn out to be electrical in nature with either blown 240/24 transformers or failures in High or Low pressure sensitive valves or involving the Definite Purpose Relays that use 24 VDC signalling coming from the House Thermostat to govern the "bulkier" flow of the more powerful 240 VAC circuit. In the case of your outside condenser unit, it might be that your large air fan used to pull heat out of the returning superheated refrigerant to "condense" it back into a liquid has failed and a simple fan motor and careful propeller blade replacement will do the trick. Most of the tests needed to check each and every electrical component in your system are available to watch and learn from on YouTube with a simple search on the term "HVAC" and "ELECTRICAL" to reveal them all...some of these will show you where to look and how to safely test the system WITH THE POWER BREAKER OFF! and find the problem components using just a basic multimeter to find things out.
Okay... But if worse comes to worse and the compressor has died an unnatural death, after un-brazing the lines and getting it out of the way... get a basic HVAC Flush System and purge all the old, burnt out oils and debris from the system line set after the pull down and vacuum of the unit. The first thing I want to let you know about is that the tools that go along with this project are NOT cheap and are not sold in any places other than either HVAC dealerships (or on eBay) , all of whom will stare you down if you do not possess the required EPA 608-609 Licenses. Remember that they mostly sell to larger outfits that buy and service complete systems rather than selling small bits and pieces of equipment to "The Great Unwashed" of our ilk. But you know me... I can be be very resourceful and have proven so in this matter already... and without saying much more.. .just look at the image attached and pay particular attention to the eBay vendor name... Just remember to lurk on the item you want to get and stay alert until the very last few minutes... and OVERBID THE LAST BID YOU CAN SEE BY UP TO FOUR TIMES THAT VALUE... Don't worry...you will not have to pay that amount unless someone else can beat your bid in less than a one minute left of bidding time.... and YOU WILL WIN THE ITEM AT $1.00 MORE THAN THE NEXT LOWEST BIDDER. I mean really...look at what the winning price for the stuff was in the attached image...and realize that this stuff sells for up to $40.00 a pound now...and will not be available after 2012...!!! Okay... THAT IS YOUR BEST OPTION!!!! With no other "Legal Entanglements" so to speak!
This guy "Dr. Z" has many of the BEST HVAC REPAIR INSTRUCTIONAL VIDEOS ON THE NET and he is a down-to-earth instructor who won't overload you with theory and garbage while just doing the repairs! Prime yourself with as many of his videos as possible and the learning curve will flatten right out. This is one video on how to R&R an outside compressor... please search YouTube for many others to get a better look at how this is done.
As for the tools... Here is the Bare Minimum...
1. Oxy-Acetylene Torch Set (I used a size 20 O2 Tank as the oxidizer and Propane and MAPP Gas and it worked fine as the fuel...they make a very nice and hot Blue Flame together!)
2. Dry Nitrogen WITH A PROPER NITROGEN HIGH AND LOW SIDE GAUGE MANIFOLD!!!! You can easily blow your system or yourself up with this stuff if not used properly!!! Use this stuff to very gently break the vacuum first purge your lines after pulling down a long vacuum session to remove all the old moisture and non-condensable gases in the line. Then use around 3 PSI of Nitrogen to pressurize the cleaned lines while brazing your fittings to prevent awful scaling inside and risking damage to your new compressor. After your system is completely sealed with new brazing(s)... vacuum down the system for at least an hour and then pressurize to 150 PSI with the Dry Nitrogen and then check your brazing points with green sticky "Predator Blood" HVAC Line goo to make certain your welds do not leak. Relieve the high pressure at 150 PSI before attempting any brazing on found leaks. Its best to use a mirror and flash light to examine your brazing points carefully. If the system holds a Nitrogen charge at 150 PSI for over an hour and the High and Low Gauges show no drop in pressure... then you will have succeeded! Very Slowly (to prevent purging Compressor Oil) Release the High Pressure at 150 PSI though your Manifold Gauge set...without letting in ambient air...and then pull another serious vacuum down to about 25 microns (CORRECTION: 500 Microns). (A Micron Gauge is expensive ...but definitive in proving how good a vacuum you manage to attain). Get a good idea of what valves to open and close on your gauges so that you don't wind up contaminating your new lines and compressor with atmospheric air accidentally ...or vent freon for the same reason. This process requires close attention to what is happening while charging or discharging this closed system at all times.
3. R-22 Manifold Gauge set to read your system High and Low Side Pressures when charging and testing the system for leaks and leak downs.
4. SilFos Silver/Copper Brazing Solder...strong and secure brazing with not too high temps to risk burning holes in your copper piping.
5. Copper Swaging Pin Set in case you need to splice any lines with lengths of new piping.
6. Fine Cloth Abrasive "Sandpaper" to clean your fittings bright and shiny and pristine clean (wipe everything off of any grit inside and out!)
7. A New Pipe Cutter to cut lengths of HVAC Copper Tubing.
8. NEW HVAC Copper Fittings and Lines... NOT standard plumbing copper pipe! in either 3/8" OD for any liquid line replacement or 7/8" or 3/4" for your vapor line replacements.
9. In order NOT to lose the existing refrigerant in your system, you will need a special HVAC Recovery Pumping and Evacuation System to salvage the R-22... God forbid it to preserve the Ozone Layer of our Earth... but sometimes accidental discharges do occur... if the old freon leaks out...you will need some more new R-22) If you can access a recovery machine...you will require an appropriate Yellow/Grey container to store the refrigerant and these can cost around $100 for a 30 Pound Recovery tank. Let me know if you will be doing this procedure and I'll provide more instructions on how it is safely done. NEVER ATTEMPT TO RECOVER REFRIGERANT IN A GREEN R-22 DISPENSING CYLINDER!!! People have been killed over-pressurizing these tanks and turning them into Freon Bombs!!
10. HVAC Refrigerant Scale... CPS Digital Model CC220. This Item is a MUST and will make your life a "Breeze with the Freeze" with re-charging the system!... because once you know how much refrigerant was originally in your system... LISTED ON THE COMPRESSOR UNIT... then you can easily and precisely WEIGH IN A NEW R-22 CHARGE (just REMEMBER TO add .6 Oz for each additional foot of 3/8" Liquid Line running from your outside compressor unit up into your air handler evaporator. The digital readout on the scale can very accurately measure pounds and ounces of coolant down to 100th part of an ounce! You must first break the vacuum on the system after light purging the lines of your R22 Manifold Gauge Set and hooking up all your lines with NO AIR in them! This is doen with the R-22 Cylinder in the upright or "Vapor Position" Then the green cylinder is inverted and set upon the freon scale after being zeroed out and weighed for its present weight. Write that number down and after checking the necessary weigh-in charge you need from the aluminum product plate mounted on your outside condenser (plus the .6 Oz. for each additional foot of liquid line running between your outside condenser unit up into your attic air handler evaporator) you simply have to use basic arithmetic to subtract the charge weight of what you need to put into your system from the present total weight of the green cylinder and note how much the green can should weigh once the full charge is installed and write down THAT number, Zero your scale and then place the green can upside down on it and plug in your 220-240 VAC Circuit Breaker and have somebody go in the house and turn on the thermostat to "COOL" and lower the setting to around 72 Degrees. If the compressor does not immediately turn on, shut off the system by pulling the circuit breaker again and weigh in about half of the needed charge via the Manifold Gauge Set LOW (VAPOR) SIDE ONLY! Close all other valves on the gauge set, especially the one Red Line for the HIGH Side liquid line. Then simply slowly open the charging valve on the green cylinder and then very slowly crack open the LOW SIDE vapor valve on your manifold gauge set to allow the liquid freon to enter the system. When you have weighed in about half of the required weigh-in charge... plug the circuit breaker back in and have your "helper" turn of thermostat to "COOL" and lower the temp down to 72 Degrees F. The new compressor should kick on and you can then you can open the LOW SIDE valve on the manifold gauge again and continue to very slowly allow the liquid freon into the low side of the system. Please remember to use only the BLUE side to do the freon charge hooked up to the larger vapor line and NOT the smaller liquid line...and so this slowly because you don't want to "SLUG" the compressor with pure liquid coming in too fast from the Low Pressure Side. After a while, the internal system pressure will normalize before you have completed the charge and the you will need to turn the green cylinder right side up to finish charging the system with the remaining weight with VAPOR only. Sometimes ...having a low heat source can help with this because by now, the lower portion of your green cylinder will be "Beer Can Cold" and condensation will be collecting around the bottom of the tank. Pros use a warming blanket to get more vapor to move from inside the tank into the HVAC unit. Don't be surprised if this takes over an hour to do this right and if you screw up the scale measurement as this is going on don't panic! Just subtract the amount of what is left inside the green tank with your starting weight and see how far along you have come. When you get to within the last pound of the process...your "Helper" should be calling your cell phone with reports on what the analog air handler vent temps are and by now...cold air should be coming out of the vents. Continue weighing in the charge slowly by controlling how much vapor is going into the LOW SIDE with precise and slow controls of the Low Side Valve on your Manifold Gauge until it reaches the exact weight needed for a full charge. Let the system run for at least fifteen minutes to stabilize and then close all the valves off...but leave everything hooked up while you go into the house to check how things feel inside. Remember...it will take a three ton unit at least 24 hours to remove all the simple and latent heat that has soaked into everything inside the house...so don't be alarmed if its not freezer room cold when you step inside your home! If things are nominal inside the house and the temperature and humidity are dropping there, go back outside and look at your gauges... for R-22 your Low Side Pressures should range between 55 and 75 PSIG for R-22 and be around 220-250 for the High Side. Of course...these pressure readings are always contingent upon atmospheric pressure and ambient heat (think of Boyles' Law here...) but if everything looks nominal and stable...close off all the valves...starting with the green tank, then the Manifold Gauges. Use a leather glove when removing the two liquid and vapor lines (Red and Blue Hoses) so you don;t get a Freon Frostbite Burn on your fingers from the escaping gases!. Get those fittings loose quickly and the immediately Brass Cap both Schrader Valves to prevent any other leaks. There will be some compressor oil inside your Manifold Gauge set that must be purged with Dry Nitrogen and then put the set inside a large plastic bag for future use. Cap off all of the lines and open female fittings with brass valve covers as well and make sure the valve on the green tank is sure and capped too. If the inside air dos not get continuously cooler and get within 3-5 degrees of the setting on your thermostat...change all of the air handler air filters and consider pulling the side panel off the air handler and using a non-acidic...non-caustic HVAC Coil Spray Cleaner to spray down your evaporator coils and then flush the unit with clean, low pressure water in a plunger style Garden Spraying Pump Unit. You should also vacuum out the condensate PVC pipe at the outside of the house to remove all the old wash outs and algae from the PVC "P" Trap and down lines to ensure your condensate pan does not get clogged and overflow into your attic. These extra steps will make it very cool and comfortable inside the home!
11. It would be nice to have a Field Piece Model HS36 Multi-Meter to be able to measure your High Side Liquid Line Sub-Cooling temps and Low Side Vapor Line Super-Heat and then just chart out your gauge pressure on a Temp/Pressure Chart for R-22... but trust me... if you add the refrigerant gradually by weight into the Low Side (NEVER IN THE HIGH SIDE!!!) and have somebody checking your AC air vents for rapidly lowering temps with some inexpensive analogue HVAC Thermometers... you will know that you are close when the Low Side Vapor Line Fitting and Service Valve close to the Outside Compressor gets to be what HVAC guys call "Beer Can Cold" as you approach the upper limit of your weighed in charge. Please...DO NOT OVERCHARGE YOUR SYSTEM!!! Having too much refrigerant will wear out your new compressor and will not make things get any colder!
12. Assuming your system uses R-22... Make certain you are using the proper compressor oil for R-22!!! The replacement compressor should have a factory charge of oil...but make certain of this.
13. A good 2.5 to 3 CFPM Vacuum pump and plenty of fresh, highly refined Vacuum Pump Oil. (About $145.00 at harborfrieght) to pull a near-perfect vacuum on your system several times before and after after the new compressor is brazed in. CHANGE THE VACUUM PUMP OIL EACH TIME B4 PULLING THE NEXT VACUUM and this will guarantee that all the non-condensable gases and water vapor and dirt are being pulled out of your system!
14. Get a an appropriate sized replacement Filter Drier canister and USE ONLY A BI-DIRECTION FILTER-DRIER IF YOUR SYSTEM IS A HEAT PUMP VS A STRAIGHT COOLING SYSTEM! In either case...REPLACE THE FILTER-DRIER WITHOUT FAIL!!!!!!!
15. You will need an Old White Cotton Tee Shirt cut up into strips to wrap around any nearby fitting manifolds on your compressor...soaked with cold water and kept wet until the brazing is complete to prevent damaging Schrader Valves. Get replacement Teflon Schrader Valve innards so you eliminate them as a possible new leak source and CAP THEM WITH BRASS SEALING STEM COVERS TO BE SURE!!!
I know I am missing some things here that may have slipped my mind...but believe me...your fix will be a piece of cake compared to what I went through! I don't think you can buy new compressor systems manufactured for R-22 any more...but you would be surprised at what you can get off of your local Craig's List and especially eBay...FOR ALL THE PARTS AND PIECES AND TOOLS NEEDED FOR THIS JOB! I'll help you along the way in every way possible to get your house cool again...
There is more to the story...and if you prefer.. you can email me your contact number here: at60dgrzbelow0@yahoo.com and I'll call you directly to help explain everything better.
Attached Files
Comment