Home |
Search |
Today's Posts |
|
Home Repair (alt.home.repair) For all homeowners and DIYers with many experienced tradesmen. Solve your toughest home fix-it problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
On Jun 23, 8:19*pm, The Daring Dufas
wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. *I replaced a couple of gas furnaces and one split ac. *I'm building a new garage with living space above it out at my lake house. *I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. *It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. *Fast according to the seller. The guy didn't know enough to shut the valves. *Instead he hacksawed off the lines. *Folded the small one over and stuffed a piece of foam in the big one. *I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. *I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) *I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. *What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. *There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. *I'd like to go ahead and vaccum it down. *Can I do that via the third tap? *I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. I don't have a nitrogen tank. My supplies are a vacuum pump, set of gauges, a can of r22. My brazing skills are sketchy so I try to minimize that. I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. I can add one to the low side. The guy moved it from one house to the another and kept it in a shed. So it got moved around a bit. I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. What happens when they go into the compressor? Will they just end up sitting in the bottom in the oil? Or the switching valve? Are these things engineered anticipating that occasional small solid might get in? This is my biggest worry. The moisture I can get out with my vacuum pump. |
#2
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
Since the system was opened for a period of time (longer
than a few minutes), it's a good idea to install a BIG liquid line filter dryer. -- Christopher A. Young Learn more about Jesus www.lds.org .. "jamesgangnc" wrote in message ... The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. I don't have a nitrogen tank. My supplies are a vacuum pump, set of gauges, a can of r22. My brazing skills are sketchy so I try to minimize that. I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. I can add one to the low side. The guy moved it from one house to the another and kept it in a shed. So it got moved around a bit. I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. What happens when they go into the compressor? Will they just end up sitting in the bottom in the oil? Or the switching valve? Are these things engineered anticipating that occasional small solid might get in? This is my biggest worry. The moisture I can get out with my vacuum pump. |
#3
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
jamesgangnc wrote:
On Jun 23, 8:19 pm, The Daring Dufas wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. I replaced a couple of gas furnaces and one split ac. I'm building a new garage with living space above it out at my lake house. I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. Fast according to the seller. The guy didn't know enough to shut the valves. Instead he hacksawed off the lines. Folded the small one over and stuffed a piece of foam in the big one. I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. I'd like to go ahead and vaccum it down. Can I do that via the third tap? I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. I don't have a nitrogen tank. My supplies are a vacuum pump, set of gauges, a can of r22. My brazing skills are sketchy so I try to minimize that. I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. I can add one to the low side. The guy moved it from one house to the another and kept it in a shed. So it got moved around a bit. I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. What happens when they go into the compressor? Will they just end up sitting in the bottom in the oil? Or the switching valve? Are these things engineered anticipating that occasional small solid might get in? This is my biggest worry. The moisture I can get out with my vacuum pump. Around here it's dirt daubers/mud daubers and other flying or crawling critters you have to worry about when a pipe is left open. The little bit of copper filings isn't a big concern. The vacuum needs to be drawn from both high and low service fittings through the gauge set. If you're worried about moisture, why on earth are you not replacing the liquid line dryer? The dryer is the first thing to replace, just don't leave it open to the air for any longer than it takes to install it. Since it's a heat pump, it requires biflow or bidirectional dryers because the refrigerant flow is reversed when changing from heat to cool. If you're worried about trash getting into the reversing valve, the best thing to do would be to remove the section of large diameter tubing and clean it out. Make sure you wrap a wet rag around the reversing valve when using your torch near it. You can always cut the tubing a distance away from the reversing valve and braze it back together with a coupling. A lot of service techs are using a low temperature silver solder on HVAC equipment which doesn't require the use of oxygen-acetylene torches. TDD |
#4
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
On Jun 24, 2:48*pm, The Daring Dufas
wrote: jamesgangnc wrote: On Jun 23, 8:19 pm, The Daring Dufas wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. *I replaced a couple of gas furnaces and one split ac. *I'm building a new garage with living space above it out at my lake house. *I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. *It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. *Fast according to the seller. The guy didn't know enough to shut the valves. *Instead he hacksawed off the lines. *Folded the small one over and stuffed a piece of foam in the big one. *I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. *I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) *I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. *What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. *There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. *I'd like to go ahead and vaccum it down. *Can I do that via the third tap? *I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. *I don't have a nitrogen tank. *My supplies are a vacuum pump, set of gauges, a can of r22. *My brazing skills are sketchy so I try to minimize that. *I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. *I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. *I can add one to the low side. *The guy moved it from one house to the another and kept it in a shed. *So it got moved around a bit. * I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. *What happens when they go into the compressor? *Will they just end up sitting in the bottom in the oil? Or the switching valve? *Are these things engineered anticipating that occasional small solid might get in? *This is my biggest worry. *The moisture I can get out with my vacuum pump. Around here it's dirt daubers/mud daubers and other flying or crawling critters you have to worry about when a pipe is left open. The little bit of copper filings isn't a big concern. The vacuum needs to be drawn from both high and low service fittings through the gauge set. If you're worried about moisture, why on earth are you not replacing the liquid line dryer? The dryer is the first thing to replace, just don't leave it open to the air for any longer than it takes to install it. Since it's a heat pump, it requires biflow or bidirectional dryers because the refrigerant flow is reversed when changing from heat to cool. If you're worried about trash getting into the reversing valve, the best thing to do would be to remove the section of large diameter tubing and clean it out. Make sure you wrap a wet rag around the reversing valve when using your torch near it. You can always cut the tubing a distance away from the reversing valve and braze it back together with a coupling. A lot of service techs are using a low temperature silver solder on HVAC equipment which doesn't require the use of oxygen-acetylene torches. TDD- Hide quoted text - - Show quoted text - Sorry if I seem stupid here, but I can't pull a vacuum through the service valves without capping the lines can I? Yes, I used silver solder on my regular hvac install at my primary residence. |
#5
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
On Jun 24, 3:27*pm, jamesgangnc wrote:
On Jun 24, 2:48*pm, The Daring Dufas wrote: jamesgangnc wrote: On Jun 23, 8:19 pm, The Daring Dufas wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. *I replaced a couple of gas furnaces and one split ac. *I'm building a new garage with living space above it out at my lake house. *I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. *It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. *Fast according to the seller. The guy didn't know enough to shut the valves. *Instead he hacksawed off the lines. *Folded the small one over and stuffed a piece of foam in the big one. *I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. *I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) *I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. *What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. *There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. *I'd like to go ahead and vaccum it down. *Can I do that via the third tap? *I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. *I don't have a nitrogen tank. *My supplies are a vacuum pump, set of gauges, a can of r22. *My brazing skills are sketchy so I try to minimize that. *I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. *I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. *I can add one to the low side. *The guy moved it from one house to the another and kept it in a shed. *So it got moved around a bit. * I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. *What happens when they go into the compressor? *Will they just end up sitting in the bottom in the oil? Or the switching valve? *Are these things engineered anticipating that occasional small solid might get in? *This is my biggest worry. *The moisture I can get out with my vacuum pump. Around here it's dirt daubers/mud daubers and other flying or crawling critters you have to worry about when a pipe is left open. The little bit of copper filings isn't a big concern. The vacuum needs to be drawn from both high and low service fittings through the gauge set. If you're worried about moisture, why on earth are you not replacing the liquid line dryer? The dryer is the first thing to replace, just don't leave it open to the air for any longer than it takes to install it. Since it's a heat pump, it requires biflow or bidirectional dryers because the refrigerant flow is reversed when changing from heat to cool. If you're worried about trash getting into the reversing valve, the best thing to do would be to remove the section of large diameter tubing and clean it out. Make sure you wrap a wet rag around the reversing valve when using your torch near it. You can always cut the tubing a distance away from the reversing valve and braze it back together with a coupling. A lot of service techs are using a low temperature silver solder on HVAC equipment which doesn't require the use of oxygen-acetylene torches. TDD- Hide quoted text - - Show quoted text - Sorry if I seem stupid here, but I can't pull a vacuum through the service valves without capping the lines can I? Yes, I used silver solder on my regular hvac install at my primary residence.- Hide quoted text - - Show quoted text - Guess I should add it's not been so open that bugs could get in. It's just that the service valves were never closed. The high side line was folded over. A piece of the low side foam was stuck in the low side pipe. |
#6
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
jamesgangnc wrote:
On Jun 24, 3:27 pm, jamesgangnc wrote: On Jun 24, 2:48 pm, The Daring Dufas wrote: jamesgangnc wrote: On Jun 23, 8:19 pm, The Daring Dufas wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. I replaced a couple of gas furnaces and one split ac. I'm building a new garage with living space above it out at my lake house. I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. Fast according to the seller. The guy didn't know enough to shut the valves. Instead he hacksawed off the lines. Folded the small one over and stuffed a piece of foam in the big one. I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. I'd like to go ahead and vaccum it down. Can I do that via the third tap? I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. I don't have a nitrogen tank. My supplies are a vacuum pump, set of gauges, a can of r22. My brazing skills are sketchy so I try to minimize that. I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. I can add one to the low side. The guy moved it from one house to the another and kept it in a shed. So it got moved around a bit. I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. What happens when they go into the compressor? Will they just end up sitting in the bottom in the oil? Or the switching valve? Are these things engineered anticipating that occasional small solid might get in? This is my biggest worry. The moisture I can get out with my vacuum pump. Around here it's dirt daubers/mud daubers and other flying or crawling critters you have to worry about when a pipe is left open. The little bit of copper filings isn't a big concern. The vacuum needs to be drawn from both high and low service fittings through the gauge set. If you're worried about moisture, why on earth are you not replacing the liquid line dryer? The dryer is the first thing to replace, just don't leave it open to the air for any longer than it takes to install it. Since it's a heat pump, it requires biflow or bidirectional dryers because the refrigerant flow is reversed when changing from heat to cool. If you're worried about trash getting into the reversing valve, the best thing to do would be to remove the section of large diameter tubing and clean it out. Make sure you wrap a wet rag around the reversing valve when using your torch near it. You can always cut the tubing a distance away from the reversing valve and braze it back together with a coupling. A lot of service techs are using a low temperature silver solder on HVAC equipment which doesn't require the use of oxygen-acetylene torches. TDD- Hide quoted text - - Show quoted text - Sorry if I seem stupid here, but I can't pull a vacuum through the service valves without capping the lines can I? Yes, I used silver solder on my regular hvac install at my primary residence.- Hide quoted text - - Show quoted text - Guess I should add it's not been so open that bugs could get in. It's just that the service valves were never closed. The high side line was folded over. A piece of the low side foam was stuck in the low side pipe. I assumed you were referring to pulling a vacuum after installation, not for storage purposes. If the pipes were plugged up in any fashion, there shouldn't be much moisture infiltration since there would still be mostly freon in the system. The dryer should still be replaced when it is finally installed. Since you have no nitrogen, R22 would be fine for putting a slight pressure on the unit for storage but when installed, it will still need a deep vacuum drawn on it. When me and my friends install a new system in the field, we pressurize it with nitrogen and leave it that way before ever pulling a vacuum and opening the valves for startup. If we don't leave the condenser because of the theft problem with new construction, we cap the line set and pressurize it with nitrogen until it's time for occupation. That way we have no surprise leaks such as those caused by other tradesmen putting a nail or screw through a pipe. The thing about dry nitrogen is that the static pressure is not going to change perceptively with a change in temperature. If you pressurize for a leak test and come back a week later when the weather has changed, the test pressure will be the same if there are no leaks. TDD |
#7
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
Yes, you'd have to cap the lines.
-- Christopher A. Young Learn more about Jesus www.lds.org .. "jamesgangnc" wrote in message ... Sorry if I seem stupid here, but I can't pull a vacuum through the service valves without capping the lines can I? Yes, I used silver solder on my regular hvac install at my primary residence. |
#8
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
On Jun 24, 6:23*pm, The Daring Dufas
wrote: jamesgangnc wrote: On Jun 24, 3:27 pm, jamesgangnc wrote: On Jun 24, 2:48 pm, The Daring Dufas wrote: jamesgangnc wrote: On Jun 23, 8:19 pm, The Daring Dufas wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. *I replaced a couple of gas furnaces and one split ac. *I'm building a new garage with living space above it out at my lake house. *I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. *It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. *Fast according to the seller. The guy didn't know enough to shut the valves. *Instead he hacksawed off the lines. *Folded the small one over and stuffed a piece of foam in the big one. *I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. *I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) *I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. *What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. *There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. *I'd like to go ahead and vaccum it down. *Can I do that via the third tap? *I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. *I don't have a nitrogen tank. *My supplies are a vacuum pump, set of gauges, a can of r22. *My brazing skills are sketchy so I try to minimize that. *I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. *I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. *I can add one to the low side. *The guy moved it from one house to the another and kept it in a shed. *So it got moved around a bit. * I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. *What happens when they go into the compressor? *Will they just end up sitting in the bottom in the oil? Or the switching valve? *Are these things engineered anticipating that occasional small solid might get in? *This is my biggest worry. *The moisture I can get out with my vacuum pump. Around here it's dirt daubers/mud daubers and other flying or crawling critters you have to worry about when a pipe is left open. The little bit of copper filings isn't a big concern. The vacuum needs to be drawn from both high and low service fittings through the gauge set. If you're worried about moisture, why on earth are you not replacing the liquid line dryer? The dryer is the first thing to replace, just don't leave it open to the air for any longer than it takes to install it. Since it's a heat pump, it requires biflow or bidirectional dryers because the refrigerant flow is reversed when changing from heat to cool. If you're worried about trash getting into the reversing valve, the best thing to do would be to remove the section of large diameter tubing and clean it out. Make sure you wrap a wet rag around the reversing valve when using your torch near it. You can always cut the tubing a distance away from the reversing valve and braze it back together with a coupling. A lot of service techs are using a low temperature silver solder on HVAC equipment which doesn't require the use of oxygen-acetylene torches. TDD- Hide quoted text - - Show quoted text - Sorry if I seem stupid here, but I can't pull a vacuum through the service valves without capping the lines can I? Yes, I used silver solder on my regular hvac install at my primary residence.- Hide quoted text - - Show quoted text - Guess I should add it's not been so open that bugs could get in. *It's just that the service valves were never closed. *The high side line was folded over. *A piece of the low side foam was stuck in the low side pipe. I assumed you were referring to pulling a vacuum after installation, not for storage purposes. If the pipes were plugged up in any fashion, there shouldn't be much moisture infiltration since there would still be mostly freon in the system. The dryer should still be replaced when it is finally installed. Since you have no nitrogen, R22 would be fine for putting a slight pressure on the unit for storage but when installed, it will still need a deep vacuum drawn on it. When me and my friends install a new system in the field, we pressurize it with nitrogen and leave it that way before ever pulling a vacuum and opening the valves for startup. If we don't leave the condenser because of the theft problem with new construction, we cap the line set and pressurize it with nitrogen until it's time for occupation. That way we have no surprise leaks such as those caused by other tradesmen putting a nail or screw through a pipe. The thing about dry nitrogen is that the static pressure is not going to change perceptively with a change in temperature. If you pressurize for a leak test and come back a week later when the weather has changed, the test pressure will be the same if there are no leaks. TDD- Hide quoted text - - Show quoted text - I gotta store it for a while. The garage/rec room is under construction at the moment. It's about done with the framing/ exterior. My back is shot so I had to hire a local guy to do most of that. I'm going to do the plumbing/electrical/hvac after he's finished. Then I'll get someone back in to do the drywall, my back's too bad for that as well. I picked this unit up because I've been collecting stuff off craig's list local materials for a few months now. If you know what you need and are not in a hurry it's a good way to get supplies cheap. Lots of new items where someone changed their mind or bought too many. This was $250 and johnstons wants $899 for it. Some risk on my part but hey that's life. I'll pull a vacuum via the third service port and follow up with a little r22 into it. I wouldn't mind having a nitrogen tank but a bargain hasn't come along yet :-) |
#9
Posted to alt.home.repair
|
|||
|
|||
Heat Pump ?s
jamesgangnc wrote:
On Jun 24, 6:23 pm, The Daring Dufas wrote: jamesgangnc wrote: On Jun 24, 3:27 pm, jamesgangnc wrote: On Jun 24, 2:48 pm, The Daring Dufas wrote: jamesgangnc wrote: On Jun 23, 8:19 pm, The Daring Dufas wrote: jamesgangnc wrote: I've done a fair bit of my own hvac work. I replaced a couple of gas furnaces and one split ac. I'm building a new garage with living space above it out at my lake house. I picked up a "slightly" used goodman 1 1/2 ton heat pump compressor off craig's list. It was installed as part of an attic conversion that was never completed. While the seller was moving out of the house the low side line was damaged and it lost charge. Fast according to the seller. The guy didn't know enough to shut the valves. Instead he hacksawed off the lines. Folded the small one over and stuffed a piece of foam in the big one. I cut them off with a pipe cutter, closed the valves, and blew them out with compressed air. I was worried that I probably did not get all the copper filings from the hacksaw so I opened the valves and blew the lines out again via the third tap. (The one that is used to check pressure during heat mode.) I didn't get a lot of air to move through it though that way so I doubt I blew out any more filings. So I'm worried that there still may be some copper filings in the lines. What else can I do? I'm also a little worried that it may have lost some oil when the low side was broken. There doesn't seem to be any easy way to drain and refill the oil though. I won't be installing it from a few months. I'd like to go ahead and vaccum it down. Can I do that via the third tap? I'll fill it with some r22 after I vacuum it. Blowing compressed air into the unit was a little bit of a bad move. People in the HVAC and refrigeration trades use dry nitrogen for internal clean out along with a suitable solvent for coils detached from the compressor. Compressed air can carry moisture into a system when blown through it. R11 isn't used as freely as it once was because it kills the poor defenseless little ozones. I use a product called CF-20 Internal Coil Cleaner available at many HVAC supply houses and it's available without any special permit: http://tinyurl.com/lk2uq3 You would have been better off leaving the valves closed and flushing out the pipe stubs with freeze spray which is basically a freon mix of some sort or even dust blaster which will blow the stuff out and leave no residue. The low side line being pierced would not cause an appreciable oil loss from an un-powered unit. Because of the compressed air introduced to the system you will need to pull a deep vacuum on the system. The warmer it is when you do it, the better it will pull out the moisture. Of course a good sized liquid line dryer like a C-163 Sporlan which is a 3/8 flare dryer which makes for easy replacement. I always add a sight glass with a moisture indicator to all the systems I install. You can get one that will screw right on to the C-163 and and attach to the tubing with a flare fitting. Heck, HVAC work isn't rocket surgery, Storman Norman does it. *snicker* TDD- Hide quoted text - - Show quoted text - The valves weren't closed when I got it so I figured the compressed air was not going to make much difference at this point. I don't have a nitrogen tank. My supplies are a vacuum pump, set of gauges, a can of r22. My brazing skills are sketchy so I try to minimize that. I'd like to have a nitrogen tank but so far I've gotten away without. I'll go ahead and pump it down and fill it with r22. I'm guessing it's ok to do that using that middle tap? It has a filter/dryer on the high side. I can add one to the low side. The guy moved it from one house to the another and kept it in a shed. So it got moved around a bit. I'm afraid that there may be some copper filings further down the low side line inside the unit that I can't really get to. What happens when they go into the compressor? Will they just end up sitting in the bottom in the oil? Or the switching valve? Are these things engineered anticipating that occasional small solid might get in? This is my biggest worry. The moisture I can get out with my vacuum pump. Around here it's dirt daubers/mud daubers and other flying or crawling critters you have to worry about when a pipe is left open. The little bit of copper filings isn't a big concern. The vacuum needs to be drawn from both high and low service fittings through the gauge set. If you're worried about moisture, why on earth are you not replacing the liquid line dryer? The dryer is the first thing to replace, just don't leave it open to the air for any longer than it takes to install it. Since it's a heat pump, it requires biflow or bidirectional dryers because the refrigerant flow is reversed when changing from heat to cool. If you're worried about trash getting into the reversing valve, the best thing to do would be to remove the section of large diameter tubing and clean it out. Make sure you wrap a wet rag around the reversing valve when using your torch near it. You can always cut the tubing a distance away from the reversing valve and braze it back together with a coupling. A lot of service techs are using a low temperature silver solder on HVAC equipment which doesn't require the use of oxygen-acetylene torches. TDD- Hide quoted text - - Show quoted text - Sorry if I seem stupid here, but I can't pull a vacuum through the service valves without capping the lines can I? Yes, I used silver solder on my regular hvac install at my primary residence.- Hide quoted text - - Show quoted text - Guess I should add it's not been so open that bugs could get in. It's just that the service valves were never closed. The high side line was folded over. A piece of the low side foam was stuck in the low side pipe. I assumed you were referring to pulling a vacuum after installation, not for storage purposes. If the pipes were plugged up in any fashion, there shouldn't be much moisture infiltration since there would still be mostly freon in the system. The dryer should still be replaced when it is finally installed. Since you have no nitrogen, R22 would be fine for putting a slight pressure on the unit for storage but when installed, it will still need a deep vacuum drawn on it. When me and my friends install a new system in the field, we pressurize it with nitrogen and leave it that way before ever pulling a vacuum and opening the valves for startup. If we don't leave the condenser because of the theft problem with new construction, we cap the line set and pressurize it with nitrogen until it's time for occupation. That way we have no surprise leaks such as those caused by other tradesmen putting a nail or screw through a pipe. The thing about dry nitrogen is that the static pressure is not going to change perceptively with a change in temperature. If you pressurize for a leak test and come back a week later when the weather has changed, the test pressure will be the same if there are no leaks. TDD- Hide quoted text - - Show quoted text - I gotta store it for a while. The garage/rec room is under construction at the moment. It's about done with the framing/ exterior. My back is shot so I had to hire a local guy to do most of that. I'm going to do the plumbing/electrical/hvac after he's finished. Then I'll get someone back in to do the drywall, my back's too bad for that as well. I picked this unit up because I've been collecting stuff off craig's list local materials for a few months now. If you know what you need and are not in a hurry it's a good way to get supplies cheap. Lots of new items where someone changed their mind or bought too many. This was $250 and johnstons wants $899 for it. Some risk on my part but hey that's life. I'll pull a vacuum via the third service port and follow up with a little r22 into it. I wouldn't mind having a nitrogen tank but a bargain hasn't come along yet :-) Keep looking, I found both of mine abandoned. Of course over the years I've exchanged them numerous times but I didn't have to pay that initial $135.00 or whatever it is now. I have two "Q" sized cylinders and I bought a good regulator which has the same fitting as an oxygen regulator but is for inert gas. Dry nitrogen is some very handy stuff to have around. I also have a gaggle of 20lb CO2 cylinders that are for soft drink fountains. Those are extremely useful when used with a high flow regulator for blowing out condensers, clearing drains, running air tools or inflating tires. I've found all manner of tanks in dumpsters and as door props. Darn, I have a bunch of propane tanks too. I'd make good terrorist. TDD |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
I want to switch from propane heat to a heat pump, any concerns? | Home Repair | |||
Heat Pump vs. 2-Stage Heat Pump | Home Repair | |||
Buddy tells me if I have elec heat and a heat pump, I can get a deal with PSE&G... | Home Repair | |||
HVAC - Oil or electric backup for new heat pump? Or oil heat only? | Home Repair | |||
Zoned heat-pump and backup heat strip question | Home Repair |