2/5/15 fb post
my aunt gave us this 5 ton hvac in very good condition but it tripped during transport and caused a leak (all freon is out so i'm not doing anything illegal here). no hvac contractor would dare fix a condenser leak because the tubing is so thin brazing it will easily put a hole. so what do i do? I FIX IT MYSELF. WHY? BECAUSE I HAVE ZERO EXPERIENCE AND KNOWLEDGE. so i pressure tested it to find the leak and immediately i hear a loud hissing (no more need for soap test). to make matters worse after i cleaned out the fins the hole was so big it would be impossible for anyone to repair. but i found a way - splice a 3/8 coupler, crimp it over, then try to braze it. i'm just waiting for the nitrogen flow meter because it's critical i get i good flow (not to low for it to die out and cause copper oxydation but not to high to blow holes on my braze). it will arrive next week. meanwhile, i will leak check the underground lines. this will be a suspense thriller because if the leak is underground, i wll have to put in new lines - run it over the attic - this will be a big job (although new set of 50 feet suction and liquid line in ebay is only $167, it will be a big job for me). i gotta do this fast because it's getting hot out here and working in the attic in extreme heat could kill me.
2/6/15 fb post
i'm not a virgin anymore. my first blow job i mean braze job. the contractor told us the lines (which run under the house) needs to be replaced because that's where the leak is. he quoted a thousand dollars. turns out the leak is outside so i just brazed it (after dismantling the return plenum). it took forever with MAPP fuel i wish i had the acetylene rig.. it's not obvious in the picture but the pipe is bent 45 degree. the idiot contractor who installed this was too lazy to use a 45 degree fitting. bending copper pipes can kink the copper and cause leaks later on (it's ok to bend the smaller diameter ones - 1/4" or 3/8"). i did another pressure check and ALLELUJAH !!! it stayed at 115 psi for 12 hours (actually 30 minutes is eough i'm just being sure). at least now i don't have to do the big job of running new line sets through the attic.
2/8/15 fb post
leak testing the lines after brazing was like a rollercoaster ride. now i know how new england patriots feel. at first i tried to be cute by isolating the the lines and evaporator from the condenser by front seating the service valves. i checked the gauge for 2 minutes and it looked fine so i was so happy but after 30 minutes, it went down 2psi. oh shit !!! i soap checked everywhere but couldn't find the leak. i was so bummed out because that means the leak is underground which means a huge expensive job. but then i thought, hopefully, the service valve gates are not leaking out because they are leaking by which is ok because it's easy to replace the service valves and i don't really need to replace it because the gates need to be fully open anyway during normal operation (i just won't be able to pump down the system whenver i need to work on the lines or evaporator that requires opening the system - like when i install a txv valve later on which i plan to do). so i backseated the gate to just test the whole system (meaning include the condenser. note i don't care if the condenser has a leak because i already have a replacement. again after 10 minutes the needle did not move and i was happy. but after 1 hour, it went down 2psi. oh crap !!! this does not look good !!! so i started soap testing and as you see here in the picture i see a leak in the service valve connection. so i simply tightened the connection and put on the cap. this time it held 115psi for 1 hour. YEY !!! but i was not sure so i left it overnight and the next day i came back to check it and it was still at 115 psi. SUPERBOWL VICTORY !!!
I RULE !!! master hvacr technicians with 30 years experience won't even dare fix this condenser leak. they say it's too difficult. so what do i do? I TRY TO FIX IT MYSELF. WHY? BECAUSE I HAVE ZERO EXPERIENCE AND KNOWLEDGE. so what's the result? SUCCESS BABY !!! i even discovered new techniques worthy of becoming new industry standards and practices. it passed the pressure test with flying colors !!! 150 freakin' PSI overnight. i pushed it to the upper limit of the compressor and yet it held. not only for the recommended 30 minutes - it held overnight. hvacr gurus don't fix condenser tube cracks because the tubes are too thin and fragile the the brazing torch will just put a hole right through like hot knife through butter. MY SOLUTION? i brace it with a thicker copper tube and only let the flame hit it and avoid the condenser tube and hope solano the solder will flow towards the joint using capillary action. it's called HEAT CONDUCTION YOU MORONS !!! another reason why they don’t fix leaks in condenser tubes is because their school taught them they should not fix it. and i agree with the rule of thumb because if a condenser leaks, that means it’s deteriorated, which means after you fix it, chances are it will leak again pretty soon. but this condenser did not leak because of deterioration. our aunt gave it to my dad and during the transport it fell from the cart. so as soon as my newest toy the nitrogen flowmeter FINALLY arrived in the mail, i wasted no time testing out my theory. after the first braze it turned out there was another hairline fracture a few inches away so i cut out the first brace and fitted in a longer brace. which was a blessing in disguise because it allowed me to test my theory that defies industry standards and convention about the amount of nitrogen flow during brazing. they say to set the nitrogen flow to 15. but with that setting i heard a hissing sound coming out of the joint which i think is a bad thing because it could easily blow a hole through the solder while it’s still liquid. so i asked myself, what’s the purpose of nitrogen? to prevent oxidation and soot contaminating the compressor. what causes oxidation? oxygen. so all i really need to do is fill the tubes with nitrogen, then seal off the valves then wait for the pressure gauge to die out to zero before i start brazing. i think nitrogen flow is required only if you have no way of sealing off the inside of the pipes. after cutting out the first brace i got to look inside the tube and EUREKA !!! clean as a whistle !!! even if i did not get a chance to look inside, i think it’s ok if there’s lots of soot because i will install a new filter drier (i bought in ebay for only $15) which is located after the condenser tube and the direction of refrigerant flow is such that the soot will get caught in the filter before it gets a chance to clog up the expansion device or get to the compressor. the only thing that sucks is i wished i bought the $200 oxy-acety rig in ebay instead of the very flaky and unstable $60 disposable oxy-mapp in home depot. many times while brazing i had to tap the oxygen valve to get back the blue neutral flame.
this sucks i’m trying to degas and remove moisture in the system before i charge it with freon but i can’t get it down to 500 microns of mercury after 2 hours it got stuck at 3000 microns. moisture and non condensate gasses will make the freon acidic and cut the lifespan of my compressor in half. i even tried the triple evacuation by getting it to 28” of mercury (in my compound gauge) then breaking the vacuum with dry nitrogen to 3 psi and let it sit for 1 hour. it could be because my pump is only a 1 stage instead of a 2 stage. but maybe because my charging hoses leaks in a vacuum it was probably designed to only withstand high pressure but permeates and leaks in a deep vacuum. maybe because high pressure causes the gaskets to seal tighter but in a vacuum it will actually get dislodged instead. i searched ebay for vacuum rated hoses they cost around $100 each (while my 3 hoses was only $24 and it even included the manifold gauge). but even with the vacuum rated rubber hoses are not even close to as good as metal hoses. metal hoses are 20 times faster.
cool. this marijuana producer just proved there is not much difference between a 2 stage and a 1 stage rotary vane. this means my hoses are the problem. http://youtu.be/FZYnK2LT4p0
this guy just proved how much faster and deeper metal hoses can pull a vacuum (metal pipe pulled it down to 80 microns in only 2 minutes while rubber hose was only 167 microns for 20 minutes). but the hvacr industry uses the less reliable and slower rubber hoses because it’s just impossible to use metal hoses. SO WHAT WILL I DO? I WILL MAKE MY OWN METAL HOSES. WHY? because according to steve jobs, nothing is impossible. http://youtu.be/cSh8YSz-M6
instead of spending $200 on hoses that are 10 times slower and less reliable, i will buy 4 of these in ebay and braze in a ¼” ID (3/8” OD) copper line left over from my liquid line. let’s see if it does the trick. can’t wait to find out.
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3/1/15 fb post
playing with my new toys – micron gauge coupler, tee, and valve core tool. turns out i don’t need a hard pipe after all. i got it down to 275 microns and after 30 minutes it only went up to 520 microns. BEAUTIFUL !!! and now i can start charging. check out the big differences – in the first column i just used a rubber hose as the gauge coupler and i can only get the system down to 4000 microns.
in the second column i did a blank off test on the brass coupler and shut off valve and i can only get it down to 700 microns and it took 30 minutes. but when i changed the oil i got it down to 265 microns in 10 minutes. whoa !!! so changing the oil often is also a big factor because oil is highly hygroscopic so of course after a while it’s ability to absorb decreases.
when my $50 vacuum rated core tool arrived, i did the blank off test and it went to 93 microns (3rd column) in just 30 seconds. HOLY COW !!! this means the shut off valve leaks in a deep vacuum so i will not use it when i vacuum the system. i then proceeded to vacuum my system and got it down to 275 microns after 3 hours and 3 oil changes. i also used a tee this time to speed it up. but i’m sure if i used metal pipes, i would have completed the process in 30 minutes. but it’s ok i do not do this for a living so time is not an issue for me.
CONCLUSION: the big factors are: 1) change oil often 2) use a vacuum rated shut off mechanism so there is no leak when isolating the gauge during the stand off test 3) use as many ports as you can (my system only has 2 service valves so i’m limited to 2) to increase conductance. this also means wider hoses increases conductance 4) use vacuum rated hoses (to minimize leak) or better yet metal pipes (rubber will degass in a deep vacuum)
3/6/15 fb post
see that number 22? that’s illegal. if you want to make $4,000 you report me to the EPA, i get fined $27,500 and you collect the 15% bounty fee. but all my facebook friends will know you ratted me out so you run the risk of ruining your reputation (although chances are people will like you more for ratting me out. hehehe).
you see 22 is inverted? that’s called liquid charging. only seasoned pros do it because you run the risk of sludging the compressor. beginners only do gas charging (right side up). but i’m doing liquid charging even if i have no experience because i’m such a nitwit and i enjoy watching the liquid through the sight glass of my manifold. actually this unit has an accumulator (white cylinder next to the black compressor) which does a great job of preventing liquid from getting to the compressor. most units don’t have an accumulator so my aunt gave us a really high end condenser unit.
it was cold (62F or 16C) that night (i golf during the day) so i wanted to see if the condenser fan is only important during hot days so i unplugged the fan and HOLY COW !!! the discharge pressure immediately jumped up from 100 psig to 250 psig (a little higher and it could destroy the compressor). that means the fan is very important to blow out the heat around the tube fins even on cold days. this also means it’s very important for you to clean the condenser from leaves and debris. this means i really need to order a high pressure cut off switch (HPS). it’s only $15 in ebay yet hvac manufacturers don’t make HPS standard because they want you to buy more compressors. hehehe. even if the fan works, the lines or filter can get clogged and cause the system to exceed pressure.
you see that weighing scale? this allows me to monitor the progress. the net weight of r22 in this tank is 10 lbs. so if the scale has decreased 5 pounds, that means i’m halfway through the charging process. what i’m doing right now is just empty the tank because this is a giant 5 ton condenser and it usually takes 2-4 lbs/ton to reach proper charge. when my next order of r22 arrives, that’s when i monitor the superheat while charging to make sure i don’t over charge (or under charge). but even with only 10 lbs it was already blowing cold air. but i know it’s still undercharged because the condensing saturation temperature should be at least 30 degrees above ambient and my red gauge reads only around 95 psig which is 55F saturation.
you see that violet jar? i use it to pour water over the compressor once in a while to speed up the charging process.
i'm not a virgin anymore. my first blow job i mean braze job. the contractor told us the lines (which run under the house) needs to be replaced because that's where the leak is. he quoted a thousand dollars. turns out the leak is outside so i just brazed it (after dismantling the return plenum). it took forever with MAPP fuel i wish i had the acetylene rig.. it's not obvious in the picture but the pipe is bent 45 degree. the idiot contractor who installed this was too lazy to use a 45 degree fitting. bending copper pipes can kink the copper and cause leaks later on (it's ok to bend the smaller diameter ones - 1/4" or 3/8"). i did another pressure check and ALLELUJAH !!! it stayed at 115 psi for 12 hours (actually 30 minutes is eough i'm just being sure). at least now i don't have to do the big job of running new line sets through the attic.
2/8/15 fb post
leak testing the lines after brazing was like a rollercoaster ride. now i know how new england patriots feel. at first i tried to be cute by isolating the the lines and evaporator from the condenser by front seating the service valves. i checked the gauge for 2 minutes and it looked fine so i was so happy but after 30 minutes, it went down 2psi. oh shit !!! i soap checked everywhere but couldn't find the leak. i was so bummed out because that means the leak is underground which means a huge expensive job. but then i thought, hopefully, the service valve gates are not leaking out because they are leaking by which is ok because it's easy to replace the service valves and i don't really need to replace it because the gates need to be fully open anyway during normal operation (i just won't be able to pump down the system whenver i need to work on the lines or evaporator that requires opening the system - like when i install a txv valve later on which i plan to do). so i backseated the gate to just test the whole system (meaning include the condenser. note i don't care if the condenser has a leak because i already have a replacement. again after 10 minutes the needle did not move and i was happy. but after 1 hour, it went down 2psi. oh crap !!! this does not look good !!! so i started soap testing and as you see here in the picture i see a leak in the service valve connection. so i simply tightened the connection and put on the cap. this time it held 115psi for 1 hour. YEY !!! but i was not sure so i left it overnight and the next day i came back to check it and it was still at 115 psi. SUPERBOWL VICTORY !!!
2/12/15 fb post
I RULE !!! master hvacr technicians with 30 years experience won't even dare fix this condenser leak. they say it's too difficult. so what do i do? I TRY TO FIX IT MYSELF. WHY? BECAUSE I HAVE ZERO EXPERIENCE AND KNOWLEDGE. so what's the result? SUCCESS BABY !!! i even discovered new techniques worthy of becoming new industry standards and practices. it passed the pressure test with flying colors !!! 150 freakin' PSI overnight. i pushed it to the upper limit of the compressor and yet it held. not only for the recommended 30 minutes - it held overnight. hvacr gurus don't fix condenser tube cracks because the tubes are too thin and fragile the the brazing torch will just put a hole right through like hot knife through butter. MY SOLUTION? i brace it with a thicker copper tube and only let the flame hit it and avoid the condenser tube and hope solano the solder will flow towards the joint using capillary action. it's called HEAT CONDUCTION YOU MORONS !!! another reason why they don’t fix leaks in condenser tubes is because their school taught them they should not fix it. and i agree with the rule of thumb because if a condenser leaks, that means it’s deteriorated, which means after you fix it, chances are it will leak again pretty soon. but this condenser did not leak because of deterioration. our aunt gave it to my dad and during the transport it fell from the cart. so as soon as my newest toy the nitrogen flowmeter FINALLY arrived in the mail, i wasted no time testing out my theory. after the first braze it turned out there was another hairline fracture a few inches away so i cut out the first brace and fitted in a longer brace. which was a blessing in disguise because it allowed me to test my theory that defies industry standards and convention about the amount of nitrogen flow during brazing. they say to set the nitrogen flow to 15. but with that setting i heard a hissing sound coming out of the joint which i think is a bad thing because it could easily blow a hole through the solder while it’s still liquid. so i asked myself, what’s the purpose of nitrogen? to prevent oxidation and soot contaminating the compressor. what causes oxidation? oxygen. so all i really need to do is fill the tubes with nitrogen, then seal off the valves then wait for the pressure gauge to die out to zero before i start brazing. i think nitrogen flow is required only if you have no way of sealing off the inside of the pipes. after cutting out the first brace i got to look inside the tube and EUREKA !!! clean as a whistle !!! even if i did not get a chance to look inside, i think it’s ok if there’s lots of soot because i will install a new filter drier (i bought in ebay for only $15) which is located after the condenser tube and the direction of refrigerant flow is such that the soot will get caught in the filter before it gets a chance to clog up the expansion device or get to the compressor. the only thing that sucks is i wished i bought the $200 oxy-acety rig in ebay instead of the very flaky and unstable $60 disposable oxy-mapp in home depot. many times while brazing i had to tap the oxygen valve to get back the blue neutral flame.
2/21/15 fb post
make sure your sprinkler is not hitting your condenser or you end up spending $5000 for a new condenser. i tried getting my old condenser to work just for fun but when i removed the fan to test it out nitrogen just starts hissing all over the place (it was still pressurized with dry nitrogen). it turns out the tubes became brittle after years of daily getting sprayed by the sprinkler so a little movement and the tubes just cracked. you have to be aware that elements in the periodic table are like the elders in your family, most of them react in a very bad way when they come in contact with each other. tap water contains calcium which causes copper to corrode and become brittle like what liquid nitrogen does to the T-1000 terminator. so i disposed the old condenser and replaced it with this new one shown here while i’m getting it ready for brazing. also did some detailing (like a car). i should zip tie those wires so it looks neat. planning to juice it up with a thermostatic expansion valve (TXV), high pressure switch (HPS), low pressure switch (LPS) and hard start kit.. this will make this baby super efficient and robust. the switches are just around $20 and the TXV and start kits are around $50. they save you a lot in electric bills and they protect your compressor from many possible damage. the question is WHY DO MANUFACTURERS MAKE TXV, HPC LPC optional features when you buy a new HVAC? why can’t they just make them standard? they are easy to install and not expensive. answer: they want to sell more compressors and condensers so after your warranty expires, they want your condenser to break as soon as possible. HAHAHAHA.
2/24/15 fb post
brazing with nitrogen to prevent copper oxidation inside the pipes that can ruin the compressor and clog the expansion device. notice i wrapped the valve with wet rag to prevent the rubber and plastic gaskets from melting. the pros use a cooling gel but a wet rag should also work. that cooling gel is so cool though i saw a demo in youtue where they put cooling gel on a styrofoam cup. it took like 30 seconds to start meling when the lit it with a brazing torch. amazing. the suction line they did not sell in home depot or lowes and hvacr supplies only sell to those with contractor's license so i had to improvise. i used the type L 3/4" ID water plumbing pipe in place of the 7/8" OD refrigerant pipe which is good enough. i googled it experts say it's ok. after brazing it i pressure tested with with 110psi for an hour and it passed so next i would vacuum this silly thing to 500 microns to get the system super clean before i put in the r-22.
2/25/15 fb post
this sucks i’m trying to degas and remove moisture in the system before i charge it with freon but i can’t get it down to 500 microns of mercury after 2 hours it got stuck at 3000 microns. moisture and non condensate gasses will make the freon acidic and cut the lifespan of my compressor in half. i even tried the triple evacuation by getting it to 28” of mercury (in my compound gauge) then breaking the vacuum with dry nitrogen to 3 psi and let it sit for 1 hour. it could be because my pump is only a 1 stage instead of a 2 stage. but maybe because my charging hoses leaks in a vacuum it was probably designed to only withstand high pressure but permeates and leaks in a deep vacuum. maybe because high pressure causes the gaskets to seal tighter but in a vacuum it will actually get dislodged instead. i searched ebay for vacuum rated hoses they cost around $100 each (while my 3 hoses was only $24 and it even included the manifold gauge). but even with the vacuum rated rubber hoses are not even close to as good as metal hoses. metal hoses are 20 times faster.
cool. this marijuana producer just proved there is not much difference between a 2 stage and a 1 stage rotary vane. this means my hoses are the problem. http://youtu.be/FZYnK2LT4p0
this guy just proved how much faster and deeper metal hoses can pull a vacuum (metal pipe pulled it down to 80 microns in only 2 minutes while rubber hose was only 167 microns for 20 minutes). but the hvacr industry uses the less reliable and slower rubber hoses because it’s just impossible to use metal hoses. SO WHAT WILL I DO? I WILL MAKE MY OWN METAL HOSES. WHY? because according to steve jobs, nothing is impossible. http://youtu.be/cSh8YSz-M6
instead of spending $200 on hoses that are 10 times slower and less reliable, i will buy 4 of these in ebay and braze in a ¼” ID (3/8” OD) copper line left over from my liquid line. let’s see if it does the trick. can’t wait to find out.
3/1/15 fb post
playing with my new toys – micron gauge coupler, tee, and valve core tool. turns out i don’t need a hard pipe after all. i got it down to 275 microns and after 30 minutes it only went up to 520 microns. BEAUTIFUL !!! and now i can start charging. check out the big differences – in the first column i just used a rubber hose as the gauge coupler and i can only get the system down to 4000 microns.
in the second column i did a blank off test on the brass coupler and shut off valve and i can only get it down to 700 microns and it took 30 minutes. but when i changed the oil i got it down to 265 microns in 10 minutes. whoa !!! so changing the oil often is also a big factor because oil is highly hygroscopic so of course after a while it’s ability to absorb decreases.
when my $50 vacuum rated core tool arrived, i did the blank off test and it went to 93 microns (3rd column) in just 30 seconds. HOLY COW !!! this means the shut off valve leaks in a deep vacuum so i will not use it when i vacuum the system. i then proceeded to vacuum my system and got it down to 275 microns after 3 hours and 3 oil changes. i also used a tee this time to speed it up. but i’m sure if i used metal pipes, i would have completed the process in 30 minutes. but it’s ok i do not do this for a living so time is not an issue for me.
CONCLUSION: the big factors are: 1) change oil often 2) use a vacuum rated shut off mechanism so there is no leak when isolating the gauge during the stand off test 3) use as many ports as you can (my system only has 2 service valves so i’m limited to 2) to increase conductance. this also means wider hoses increases conductance 4) use vacuum rated hoses (to minimize leak) or better yet metal pipes (rubber will degass in a deep vacuum)
many say a 2 stage pump is 2 times faster than a single stage pump which i'm using here. although i found a video in youtube disproving this theory.
see that number 22? that’s illegal. if you want to make $4,000 you report me to the EPA, i get fined $27,500 and you collect the 15% bounty fee. but all my facebook friends will know you ratted me out so you run the risk of ruining your reputation (although chances are people will like you more for ratting me out. hehehe).
you see 22 is inverted? that’s called liquid charging. only seasoned pros do it because you run the risk of sludging the compressor. beginners only do gas charging (right side up). but i’m doing liquid charging even if i have no experience because i’m such a nitwit and i enjoy watching the liquid through the sight glass of my manifold. actually this unit has an accumulator (white cylinder next to the black compressor) which does a great job of preventing liquid from getting to the compressor. most units don’t have an accumulator so my aunt gave us a really high end condenser unit.
it was cold (62F or 16C) that night (i golf during the day) so i wanted to see if the condenser fan is only important during hot days so i unplugged the fan and HOLY COW !!! the discharge pressure immediately jumped up from 100 psig to 250 psig (a little higher and it could destroy the compressor). that means the fan is very important to blow out the heat around the tube fins even on cold days. this also means it’s very important for you to clean the condenser from leaves and debris. this means i really need to order a high pressure cut off switch (HPS). it’s only $15 in ebay yet hvac manufacturers don’t make HPS standard because they want you to buy more compressors. hehehe. even if the fan works, the lines or filter can get clogged and cause the system to exceed pressure.
you see that weighing scale? this allows me to monitor the progress. the net weight of r22 in this tank is 10 lbs. so if the scale has decreased 5 pounds, that means i’m halfway through the charging process. what i’m doing right now is just empty the tank because this is a giant 5 ton condenser and it usually takes 2-4 lbs/ton to reach proper charge. when my next order of r22 arrives, that’s when i monitor the superheat while charging to make sure i don’t over charge (or under charge). but even with only 10 lbs it was already blowing cold air. but i know it’s still undercharged because the condensing saturation temperature should be at least 30 degrees above ambient and my red gauge reads only around 95 psig which is 55F saturation.
you see that violet jar? i use it to pour water over the compressor once in a while to speed up the charging process.
when charging always remember to bleed the hoses first or all your vacuuming efforts will be useless. you can never bleed too much. it’s when you don’t bleed – it’s when things go wrong. air is the enemy of pressurized systems. just like when i used to work on my car brakes i was always bleeding the hoses.
i will show you a poor UP los banos agriculture student style of measuring relative humidity. amazing how this condenser my aunt gave us that had a leak no hvac contractor would dare fix. i have zero experience and knowledge yet i fixed it and now it’s blowing super cool air – 48f supply air with 20f split. SAVED ME $5k !!!
now i will measure superheat (SH) to make sure it’s not overcharged which causes liquid freon to get to the compressor and mix with the oil, causing it to lose it’s viscosity and wearing out the parts. a new compressor cost $600 not to mention having to do recovery, evacuation (vacuuming) and recharge. the normal SH is 8-15 for normal conditions but since it’s not yet summer (70f ambient) i have to measure the target SH i want to get the exact target SH recommended by the manufacturer just for fun. the label says to use a sling psychrometer which costs $100 so i will just use a regular thermometer and wrap it with wet paper towel or shoelace (los banos style). then i just insert it in the return air plenum to get the wet bulb reading.
video of a cheap left wing liberal communist UP los banos agriculture student measuring relative humidity in baker field. https://youtu.be/ZsPETRXFU0s
americans and their fancy sling psychrometers. this is why the world hates america. https://youtu.be/mB9VTmQ5V4o
ateneo student measuring relative humidity in the laboratory. giving me a boner. https://youtu.be/J5NaW7NyikI
but with a $400 testo, you just wet the wick, insert in the return air plenum, clamp the thermocouple to the suction pipe and you can just press a button to switch between SH and target SH. no need for computations, referring to graphs and charts. but i'm not a professional so i will not buy this. https://youtu.be/NV0XmxrnBao
3/14/15 fb post
many contractors will see this abnormally low suction pressure and add more refrigerant. WRONG !!! this could overcharge the system, cause high compression ratio and discharge temperature, waste electricity or even ruin the compressor. suction pressure is too low here because:
1) not yet summer.(low ambient). hopefully increase in heat load will increase suction pressure so the evaporator won't frost which could cause restriction in air flow.
2) over sized condenser = undersized metering device – causing restriction. solution is to change the fixed orifice with a txv ($60) (need to pump down, install txv, evacuate to 500 microns). i won't even bother measuring subcool or measure the compressor discharge temperature to verify. the normal discharge pressure says says it all.
3) dirty air filter. but i checked it's clean.
as you see here, suction pressure is 45psig = 20F. suction temp is 32F so 32-20=10F superheat. perfect !!! so SH is good, evap surface is cold, so what's the problem? the problem is the compressor will needs to work harder to bring the pressure inside the coil to condensing pressure (high compression ratio). 45psig to 225 psig is more work than 75psig to 225psig because there is less gas sucked in and less pushed out for each stroke of the compressor piston so it needs more strokes (less volumetric efficiency) causing more heat and if compressor discharge temp is above 250F, that means compressor temp is 325F and the oil starts to break down at 350F so not good.
(notice i had to wrap the meat thermometer with duct tape and wrap it with insulation. with the $400 testos, just clamp it and it seconds you get the reading - very helpful if you do this for a living. but i'm not a pro so hello duct tape)
for the first time in my life i used a duct tape to tape a duct. the return air duct was very unstable it easily gets dislodged and there was a huge leak at the back end we could not see so for many years our a/c was operating at lower efficiency and paying higher electric bill. the contractor lazily used a carpet padding to attach this duct so of course after a while the duct tape does not stick to the deteriorating foam. so i decided to drape a heavy duty garbage bag, folded one end like 10 times to make the lining very thick and strong then i just went TRIGGER HAPPY with the staple gun.
2/15/15 fb post
2/15/15 fb post
lucky the biggest drill bit i had is just right size for the toggle nut whenever a switch box is taken out the toggle nut needs to be replaced because it falls down inside the wall after you unscrew the bolt. but what if the hvac dude did not bring a spare toggle nut? i have no experience in hvacr but i just found a technique worthy of becoming an industry standard or best practice. what i did was cut off the head of the bolt and replaced it with a regular hex nut. so now it’s much easier to remove (unscrew the hex nut) and install the switch box (screw in the hex nut).
2/7/15 fb post
having fun with capacitors. ALWAYS SHORT OUT THE TERMINALS WITH A SCREWDRIVER even if the power is off or you will get zapped. even the very rusty and old start capacitor of the old condenser is still good - 40 microFarads. after 22 years finally got a digital multi-meter($34). actually these capacitors tested good with my old analogue even without a capacitance meter - a capacitor is just a battery, except it only holds the charge for a few seconds. so when i ohm test it with the analogue tester, the needle should slap to the right, just like what happens when you ohm test a battery. however with a capacitor, the needle should slowly move to the left .but seeing the old capacitor is very very very rusty and tested out good, i did not trust the analogue test and so i went to home depot to get me the digital one with capacitance tester.
2/20/15 fb post
time for some experiment using a cheap marijuana production gadget. i was thinking, why not use water as a refrigerant? if you lower the pressure the boiling point of water goes down. that is why when i was boiling potatoes when i was snowboarding in aspen (8000 ft above sea level) it took forever because the boiling point at that altitude is 91 celsius instead of 100 because the pressure is lower (as you know once it starts boiling temperature of water cannot go any higher. however the temperature of steam can go higher thus the pressure cooker). why is the pressure lower at higher altitude? because there is less air due to less gravity. air is a molecule. air is a matter. gravity pulls down matter. more air increases pressure like in a balloon.
another word for boiling point is saturation point or i like to call it “fastest evaporation point”.
so i googled the saturation chart of water and found out that at 0.088 psi (4,572 microns), the boiling point of water becomes freakin’ 0 degree celsius. this means water can even be used as a freezer refrigerant if we lower the pressure enough. how do you lower the pressure? answer: vacuum (have you seen the movie gravity where the face of the astronaut freezes up when exposed to vacuum? vacuum is simply 0 pressure). i googled and found out they use deep vacuum for marijuana processing and since home production of marijuana is sprawling all over the US, i got to buy a deep vacuum in ebay for only $50 and the gauge for $80 (law of supply and demand). it only took me 20 seconds to reach 0.088 psi. and after 15 minutes it was at freakin .01 psi (500 microns). at this pressure, water boils at a freakin’ -20 celsius. HOLY COW !!! but maybe it’s not economical because an air conditiner or freezer that uses water as a refrigerant probably cost more energy and more expensive to manufacture, not to mention corrosion. but at least i got to satisfy my experiment craving.
what is the significance of the boiling point? because it’s during boiling or rapid evaporation when a liquid can RAPIDLY absorb the most heat, assuming the surrounding temperature is hotter. heat absorption results in cooling the surrounding air. it’s confusing because when we boil water at atmospheric pressure the surrounding temperature is colder and the boiling water is much hotter so it’s not cooling the surrounding air in fact it’s heating it up that’s why when we think of the word boiling, the word HEATING is in our mind. so let’s use the word saturation point from now on because it’s less confusing. when the saturation point is lower than the surrounding temperature, it will cool the surrounding air. the saturation point of water at normal atmospheric pressure is 100 celsius. we need to lower the pressure to lower the saturation point. however, the saturation point of r-22 freon is a whopping -41 celsius (similar to propane and ammonia that is why farmers in america use propane for their cooling and food preservation needs because it’s much cheaper). in fact freon can still cool the surrounding air even at higher pressures or higher saturation point. there needs to be higher pressure present to move the liquid around the tubes in the airconditioning system. that is why the the evaporator coil is around 7 celsius not -41 because the pressure is now higher (the pressure inside the evaporator is not normal atmospheric pressure).
what is the purpose of the compressor? 1) it creates difference in pressure in both sides to push the liquid to the evaporator 2) for a gas to turn to liquid or condensate, it needs to release heat. this can only happen if the air around it is colder (heat travels from hot to cold).
but the air temperature is hot (the reason why we need airconditioner in the first place). so how do we make the gas (evaporated from the evaporator) hotter than the surrounding air? by compressing the gas, resulting in higher pressure, resulting in more molecules bumping each other because the space is much tighter now (thus the word compression). so we make the condenser tubes thinner so the compressor does not have to work harder. but it takes time to release heat. we can speed up the release of heat by attaching thin fins to the tube and blowing the fins with air using a fan. we can also give it time by making the pipe very long. but we have limited space. that is why we coil the tube – thus the condenser coil. we can even make it longer to give time for the liquid to cool down enough so by the time it gets to the evaporator it’s cool enough. it is even made cooler by making the entrance to the evaporator smaller (expansion device) resulting in less flow resulting in less pressure resulting in less saturation point. (the word expansion device is another confusing term because it’s actually constricting the tube so the liquid pressure decreases after passing through the device)
why do we need to turn the evaporated gas from the evaporator into liquid (condensation)? so we can let it evaporate it again -it's during evaporation where absorption of heat is fastest - fast enough to cool the surrouding air (if the surrounding air is warmer).
i also wrote this article that can give a better understanding on how aircons work - http://ian-crystal.blogspot.com/2018/10/knowledge-bomb-about-heat-energy.html
2/20/15 fb post
another word for boiling point is saturation point or i like to call it “fastest evaporation point”.
so i googled the saturation chart of water and found out that at 0.088 psi (4,572 microns), the boiling point of water becomes freakin’ 0 degree celsius. this means water can even be used as a freezer refrigerant if we lower the pressure enough. how do you lower the pressure? answer: vacuum (have you seen the movie gravity where the face of the astronaut freezes up when exposed to vacuum? vacuum is simply 0 pressure). i googled and found out they use deep vacuum for marijuana processing and since home production of marijuana is sprawling all over the US, i got to buy a deep vacuum in ebay for only $50 and the gauge for $80 (law of supply and demand). it only took me 20 seconds to reach 0.088 psi. and after 15 minutes it was at freakin .01 psi (500 microns). at this pressure, water boils at a freakin’ -20 celsius. HOLY COW !!! but maybe it’s not economical because an air conditiner or freezer that uses water as a refrigerant probably cost more energy and more expensive to manufacture, not to mention corrosion. but at least i got to satisfy my experiment craving.
what is the significance of the boiling point? because it’s during boiling or rapid evaporation when a liquid can RAPIDLY absorb the most heat, assuming the surrounding temperature is hotter. heat absorption results in cooling the surrounding air. it’s confusing because when we boil water at atmospheric pressure the surrounding temperature is colder and the boiling water is much hotter so it’s not cooling the surrounding air in fact it’s heating it up that’s why when we think of the word boiling, the word HEATING is in our mind. so let’s use the word saturation point from now on because it’s less confusing. when the saturation point is lower than the surrounding temperature, it will cool the surrounding air. the saturation point of water at normal atmospheric pressure is 100 celsius. we need to lower the pressure to lower the saturation point. however, the saturation point of r-22 freon is a whopping -41 celsius (similar to propane and ammonia that is why farmers in america use propane for their cooling and food preservation needs because it’s much cheaper). in fact freon can still cool the surrounding air even at higher pressures or higher saturation point. there needs to be higher pressure present to move the liquid around the tubes in the airconditioning system. that is why the the evaporator coil is around 7 celsius not -41 because the pressure is now higher (the pressure inside the evaporator is not normal atmospheric pressure).
what is the purpose of the compressor? 1) it creates difference in pressure in both sides to push the liquid to the evaporator 2) for a gas to turn to liquid or condensate, it needs to release heat. this can only happen if the air around it is colder (heat travels from hot to cold).
but the air temperature is hot (the reason why we need airconditioner in the first place). so how do we make the gas (evaporated from the evaporator) hotter than the surrounding air? by compressing the gas, resulting in higher pressure, resulting in more molecules bumping each other because the space is much tighter now (thus the word compression). so we make the condenser tubes thinner so the compressor does not have to work harder. but it takes time to release heat. we can speed up the release of heat by attaching thin fins to the tube and blowing the fins with air using a fan. we can also give it time by making the pipe very long. but we have limited space. that is why we coil the tube – thus the condenser coil. we can even make it longer to give time for the liquid to cool down enough so by the time it gets to the evaporator it’s cool enough. it is even made cooler by making the entrance to the evaporator smaller (expansion device) resulting in less flow resulting in less pressure resulting in less saturation point. (the word expansion device is another confusing term because it’s actually constricting the tube so the liquid pressure decreases after passing through the device)
why do we need to turn the evaporated gas from the evaporator into liquid (condensation)? so we can let it evaporate it again -it's during evaporation where absorption of heat is fastest - fast enough to cool the surrouding air (if the surrounding air is warmer).
i also wrote this article that can give a better understanding on how aircons work - http://ian-crystal.blogspot.com/2018/10/knowledge-bomb-about-heat-energy.html
11/19/14 fb post
yey the power supply and sequencer for the electric furnace arrived. check out the sleek way i covered the unused blue 208v in the middel i capped it with a connector and wraped electric tape around the metals.
but i found out there was nothing wrong with the sequence because after replacing the sequencer it still does not work. turns out the condenser was a heat pump so the thermostat wire that turns on the heat was connected to the heat pump instead of the furnace. i reconnected it to the furnace and NOW THE HEATER WORKS.
12/6/13 fb post
troubleshooting time. the transformer outputs 14v so it's good. the fan runs ok, and it's connected to the contactor so i assume the contactor is good. i disconnected the wires to the coils and ran continuity check, and the coils and the fuse were good. now the only suspect is the heat sequencer. i was trying to remove a stubborn wire stuck to a connector and zapped the transformer. so now i can't test the sequencer because i don't have a power supply. i removed the sequencer and performed continuity checks and it was good. but i need the lower voltage (ac 14v) to test it. so i just went to the internet and ordered the transformer ($10) and the sequencer ($15). meanwhile, i will test the coils by bypassing the sequencer and see if the coils glow.
mcgyver time. i'm too lazy to go to radioshack to buy a female to female connector or even connect 2 of these male connectors with a wire so i just cut it so i can have a temporary female to female connector (sounds like a sex toy). after bypassing the heat sequencer, i turned on the switch at the main panel in the backyard (this furnace is in the garage), sprinted back to the garage to check if the coils are heating up. as soon as i entered the garage door i immediately felt the heat on my face. PRESTO !!! this means the sequencer is the culprit. i immediately sprinted back to the panel to turn it off because the coils are suppose to be on only a minute at a time (that's the purpose of the sequencer it cycles the coil on and off every minute or else the coil will overheat). i don't know why this furnace don't have an on/off switch.
5/29/15 fb post
think outside the box. metal hoses are 20 times faster than rubber hoses in vacuuming an hvacr system but nobody in the industry uses metal hoses because it's not flexible. i'm just a newbie/hobbyist yet i'm already challenging and breaking industry norms and conventions and discovering new techniques. turns out a 3/8" copper line is flexible enough. i didn't even use a coupler the 15% silver silfos is so strong i just placed the ends together and brazed over it. nobody in the industry ever brazes 2 pipes together without a coupler yet i did it and it worked. it tried to break it, stress tested it and it's very solid. it went to 191 microns in 15 seconds compared to my rubber hose which took 20 minutes. this should allow me to evacuate 5 ton system in 30 minutes instead of 4 hours. this is so much fun.
(for more of my knowledge bombs, click the "ian's knowledge bombs" banner at the top of this article and choose any article in the table of contents that piques your interest)
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