scott degroot
Well-Known Member
Seems like we have people from all job fields that frequent here, anybody do home heating and ac? I'd like to pick your brain if you don't mind.
Home AC
- Thread starter scott degroot
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Gary DiPietroSr
Well-Known Member
A very good friend of mine does. He and I installed my 3rd zone hydro air system.
Ron N
Well-Known Member
Scott, If I can help, just post a question. I work on big A/C systems now but did mostly residential for 15 years before that. I am fixing to head to bed now, but will check in tomarrow night._Ron
scott degroot
Well-Known Member
Ron
I live in Phoenix...now that that's out of the way. I've got a 3.5 ton package unit(heat pump) on my roof and about 2.5 years ago had a compressor put on it. After that the unit cooled better than it ever has since I have owned the house. Last Dec it started freezing up when it got cold out (for here anyway) the home warranty company sent someone out and they told me that the unit was dirty and needed to be cleaned, of course the warranty company doesn't cover cleaning, no big deal. I have the guy clean the unit to the tune of $380 and when all is said and done he lugs a bottle of or R22 up there and charges the unit up and says i was also low...hmmmm...isn't that why it was freezing up, 2 days later the unit freezes up again but not as bad and before it can happen again we loose our cold weather here. Anyway summer rolls around and the ac isn't performing like it used. Someone comes out, charges it(2 lbs), and now it is blowing colder but not like it used to. 2 weeks later and the cooling noticebly diminishes, guy comes back out and says he didn't put enough in and charges it again with 4 lbs this time. When he leaves it is nice and cold again and there is about a 22 degree difference between the air going in and the air coming out. Last week it starts going downhill again, guy comes back out and says that now there is a leak in the indoor coil and that the unit is too old to repair(it is 20 years old) and they have to replace it. Warranty co sends out another guy to look at it and he tells me that it is now overcharged and there is no leak. He seems like the best contractor that they have sent out so far but is telling me that the unit is cooling and he isn't sure what is going and he is going to talk to the previous contractor before getting back with the home warranty company. I know for a fact that when he put gauges on the system that he didn't hook to the high side because there is an issue with the service valve and that he is solely relying on temperatures to make his decisions...is this acceptable? The basics of ac are pretty much the same for car verses home and I know that I can't solely rely upon component temperatures when diagnosing a car ac system. He says that he didn't find any leaks but he doesn't use a sniffer either? Are there any questions that I should be asking these people that may help to pinpoint my problem? Is the temperature split between the air going into the unit and the air coming out of the unit an acceptable way to judge system performance, which by the way is now down to 12 degrees difference. Even during the hottest of days here I am able to keep the house at 75 degrees and have the unit cycle. Last weekend, which wasn't hot for here yet, the temp stayed at 78 and the unit ran all day long so I know that something is going on. Any insight you can give me would be greatly appreciated.
I live in Phoenix...now that that's out of the way. I've got a 3.5 ton package unit(heat pump) on my roof and about 2.5 years ago had a compressor put on it. After that the unit cooled better than it ever has since I have owned the house. Last Dec it started freezing up when it got cold out (for here anyway) the home warranty company sent someone out and they told me that the unit was dirty and needed to be cleaned, of course the warranty company doesn't cover cleaning, no big deal. I have the guy clean the unit to the tune of $380 and when all is said and done he lugs a bottle of or R22 up there and charges the unit up and says i was also low...hmmmm...isn't that why it was freezing up, 2 days later the unit freezes up again but not as bad and before it can happen again we loose our cold weather here. Anyway summer rolls around and the ac isn't performing like it used. Someone comes out, charges it(2 lbs), and now it is blowing colder but not like it used to. 2 weeks later and the cooling noticebly diminishes, guy comes back out and says he didn't put enough in and charges it again with 4 lbs this time. When he leaves it is nice and cold again and there is about a 22 degree difference between the air going in and the air coming out. Last week it starts going downhill again, guy comes back out and says that now there is a leak in the indoor coil and that the unit is too old to repair(it is 20 years old) and they have to replace it. Warranty co sends out another guy to look at it and he tells me that it is now overcharged and there is no leak. He seems like the best contractor that they have sent out so far but is telling me that the unit is cooling and he isn't sure what is going and he is going to talk to the previous contractor before getting back with the home warranty company. I know for a fact that when he put gauges on the system that he didn't hook to the high side because there is an issue with the service valve and that he is solely relying on temperatures to make his decisions...is this acceptable? The basics of ac are pretty much the same for car verses home and I know that I can't solely rely upon component temperatures when diagnosing a car ac system. He says that he didn't find any leaks but he doesn't use a sniffer either? Are there any questions that I should be asking these people that may help to pinpoint my problem? Is the temperature split between the air going into the unit and the air coming out of the unit an acceptable way to judge system performance, which by the way is now down to 12 degrees difference. Even during the hottest of days here I am able to keep the house at 75 degrees and have the unit cycle. Last weekend, which wasn't hot for here yet, the temp stayed at 78 and the unit ran all day long so I know that something is going on. Any insight you can give me would be greatly appreciated.
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Jerry Abson 3
Well-Known Member
Scott,
I had kinda the same problem about 20 years ago, I found the best way to fix it was to move away!
sorry, couldn't resist. Wish I could help, but I don't know anything about AC.
I had kinda the same problem about 20 years ago, I found the best way to fix it was to move away!
sorry, couldn't resist. Wish I could help, but I don't know anything about AC.
Larry Hampton
Active Member
Put a Swamp Cooler in. We had one in Albuquerque and it would freeze your tail off, kept the whole house cool.
Is it a split system or an all in one unit? When my split system freezes up, it's usually due to my A-coil being dirty. I spray my condenser down with a hose a couple times a year, but it sits on the ground.
Is it a split system or an all in one unit? When my split system freezes up, it's usually due to my A-coil being dirty. I spray my condenser down with a hose a couple times a year, but it sits on the ground.
scott degroot
Well-Known Member
It's an all in one unit. Unit doesn't freeze up in ac mode, only happened when it was really cold out. Had the unit cleaned in begining of Jan and it is spotless adn I'm not a big fan of swamp coolers as they are useless here during monsoon season due to the humidity.
JerryA
Wasn't my idea to move here..
JerryA
Wasn't my idea to move here..
Jerry Abson 3
Well-Known Member
Ah, sorry bout that. Good thing though, just found out that they Yotes are heading my way in September for an exhibition with Tampa Bay!
told the wife to hold off any and all purchases until we can buy the best seats in the house when the tickets go on sale. She asked what about food, I said we can eat when we get there!
She doesn't think I am funny. At least she thinks I am cute. Glad love is blind!
When I lived there we couldn't afford one, we had the good old swamp cooler that always had to be cleaned and pads replaced on the hottest freakin day of the summer.
Good luck on that AC,
told the wife to hold off any and all purchases until we can buy the best seats in the house when the tickets go on sale. She asked what about food, I said we can eat when we get there!
She doesn't think I am funny. At least she thinks I am cute. Glad love is blind!
When I lived there we couldn't afford one, we had the good old swamp cooler that always had to be cleaned and pads replaced on the hottest freakin day of the summer.
Good luck on that AC,
scott degroot
Well-Known Member
It's only supposed to hit 115 on Sat...but it's a dry heat
Jerry Abson 3
Well-Known Member
yea, right! I remember that dry heat, still freaking hot!
Ron N
Well-Known Member
To start out. There are only two reasons to freeze up ( ice on inside air evaporator coil). They are lack of air flow(dirty coil,blower slowing down do to going bad) and low refrigerant pressure. Low refrigerant pressure, can be caused by using the A/C( not the heat pump) during cold weather. But usually this is with outside temperatures below 45 degrees and the unit does not have a fan pressure control for the condensor(outside exposed fan). Sometimes it is combined with refrigerant being a little low. I haven't seen a heatpump with this type of control. On a note about the temperature difference between inlet and outlet air. The norm that the factory technicians told me( now this was a while back) should be between 15 to 18 degree's. I would try to set it according to each unit by the superheat and subcooling chart and then add a little more. I would try to get a difference of 17 to 19 degrees. this is also dependent of how close the return and supply air is to the unit.That does sound like quite a bit of refrigerant to add to a combination unit that is cooling a little, with no leaks of course. As far as being acceptable with only hooking up to the low side. Not really. You are only seeing half the picture. You cannot tell if the compressor is working properly or if the condensor is working properly. One of the problems with a unit not cooling properly as the outdoor temperature rising, could be the condensor coil not making the proper amount of liquid refrigerant. This could be due to the fan slowing down. the condensor coil works like a radiator on a car. It cools the refigerant down to a liquid. If the coil is having trouble transfering the heat.It will not cool the air as well. Answers to the questions in the next post.lol _Ron
scott degroot
Well-Known Member
Thanks for your time Ron. I am convinced that either one of 3 things is going on. Either the unit is leaking somewhere, one tech confirmed with a leak detector and the other tech said no but he didn't have a leak detector, the compressor is having issues even though it was replaced 2 years ago doesn't mean that the job was done right or there is a condensor issue. I am still curious as to what the high side pressure is as I think this is crucial to diagnosing the problem. I expect to hear back from the last guy that looked at it tomorrow and I'll let you know what is happening.
Aaron Lolos
Member
Hey there, had to chime in my .02 here. I'm a hvac tech here in MA and from what your saying, it sounds to me that your have a refrigerant leak in the system.
I'm basing that on the fact that the units freezing up, and they keep adding R22.
A properly charged system should give you around a 15-20 degree temp drop across your A coil. (intake vs outlet temps) If its higher the system may be under charged or your filter or A coil could be clogged. If I recall a 3.5 ton system should have 2100 cfm through it. A slow leak will stay in spec for a while, then get very cold as the low side pressure drops out of spec and usually ice up in the process before it stops working all together when it runs dry. Another handy test is checking the compressor running amp draw. Its stamped on the compressor. Low charge causes low running amps.
My personal pet peeve and an indicator of the pride people take in their work would be to sneak a peek over the shoulder of the guy when he takes the cover off the unit, make sure they secured the start capacitor to the chassis. Seems like a no brainer, but I can't tell you how many times I've opened units that have been previously serviced only to find out the cap is hanging by the wires and either still in its shipping box or they just wrapped it with electric tape because the tech couldn't be bothered to do a nice job.
As for finding a leak, I've always found it very difficult with a sniffer. The fans tend to blow all the freon away. If its off and in an enclosed space (think walk in fridge) they scream as soon as you open the door from the build up. So my opinion of them is low for the $1500 they want for the gadget. I've found more leaks with a flashlight looking for the oil that circulates in the system and bubble solution. If your loosing 4+ lbs of R22 in two weeks it should leave a mess somewhere. My first choice would be the welds from the compressor you had replaced a few seasons ago, a hairline crack in a line will do it. The reversing valve and then any fittings that are set with flair nuts can also be good places to look. If your system has a filter drier and a sight glass, (it should if the compressor was replaced) check those joints too.
Hope this helps
Stay cool!
I'm basing that on the fact that the units freezing up, and they keep adding R22.
A properly charged system should give you around a 15-20 degree temp drop across your A coil. (intake vs outlet temps) If its higher the system may be under charged or your filter or A coil could be clogged. If I recall a 3.5 ton system should have 2100 cfm through it. A slow leak will stay in spec for a while, then get very cold as the low side pressure drops out of spec and usually ice up in the process before it stops working all together when it runs dry. Another handy test is checking the compressor running amp draw. Its stamped on the compressor. Low charge causes low running amps.
My personal pet peeve and an indicator of the pride people take in their work would be to sneak a peek over the shoulder of the guy when he takes the cover off the unit, make sure they secured the start capacitor to the chassis. Seems like a no brainer, but I can't tell you how many times I've opened units that have been previously serviced only to find out the cap is hanging by the wires and either still in its shipping box or they just wrapped it with electric tape because the tech couldn't be bothered to do a nice job.
As for finding a leak, I've always found it very difficult with a sniffer. The fans tend to blow all the freon away. If its off and in an enclosed space (think walk in fridge) they scream as soon as you open the door from the build up. So my opinion of them is low for the $1500 they want for the gadget. I've found more leaks with a flashlight looking for the oil that circulates in the system and bubble solution. If your loosing 4+ lbs of R22 in two weeks it should leave a mess somewhere. My first choice would be the welds from the compressor you had replaced a few seasons ago, a hairline crack in a line will do it. The reversing valve and then any fittings that are set with flair nuts can also be good places to look. If your system has a filter drier and a sight glass, (it should if the compressor was replaced) check those joints too.
Hope this helps
Stay cool!
Ron N
Well-Known Member
If he didn't see any leaks, that means that he probably just did a visual inspection. A visible sign of leaks is oil on the surface of the unit around the copper or aluminum. Alot of grimey dirt can be a sign as well. The use of soapy water in a spray bottle can spot a leak, just like finding a gas leak on natural gas lines. If bubbles show up, then you have a leak. Sometimes you can have a leak on a schraeder valve.(The valve where they hook up the gauges.) They usually have screw on caps, if these are left loose, then you can loose refrigerant there. If the last tech that added refrigerant, screwed it on tight, this could have fixed the leak temporarily. If the last tech did not hook up the gauges to the high side this could have been what the problem was. As far as being overcharged, the only way to tell is having both the low and high side connected to the gauges. The questions that you can ask.(Add your voice here, haha.
First question. Why couldn't you hook the high side up. Is it do to the high side hookup(schrader valve) blowing refrigerant out, when you were taking the cap loose?
Second question. If it is leaking, how much to repair it. Because from what I have heard you can't tell how the unit is running with out reading the high side gauge.
Third question. Do you think that maybe the condensor fan motor might be going bad?
Forth question. Why is it that last year the A/C was working good and this year it isn't keeping up with the heat? ( Be nice asking this question, you are asking them for their opinion.)
Fifth question. Do you remember what the low side pressure was. (the normal on a hot day, with the house at 75 degrees should be between 65 and 78 pounds of pressure. This is also dependent on the effeciency of the unit.)
Side note on pressures. The high side is dependent on outside temperature, as the temperature rises outside so should the pressure. this can be as much as forty to fifty pounds difference. The low side pressure is dependent on inside the house temperature. The warmer the house the higher the pressure. But only in small amounts. such as two to five pounds of pressure.
One thing that you can try, is during the heat of the day, put your thermometer in the outlet and measure the temperature. Then have someone read it while you spray water on the outside coil( the one exposed to the air). If the temperature of the outlet air changes significantly, then the condensor coil or the compressor or both are not operating very well.
The last question and the worst one of all. How much will it cost to replace the unit.
Over the years I have seen units fail over a years time, the signs are usually they just quit cooling, The compressor start making unusual noises and just is not working right. They have small valves in them(usually reed valves) that get bent or do not seal against the head anymore. The pistons are leaking by. But the only way to tell is by hooking up the high side on things like that to see the pressures.
Another thing that they can look at is to check to see if the refrigerant is contaminated or has noncondensibles( a big word meaning that the refrigerant has moisture of dirt in it that doesn't let it make a good liquid). they can do that by turning the unit off for a while and hook up the low side gauge. If the standing pressure doesn't change anymore, they can compare the pressure temparature to a refrigerant temperature chart. Usually built into the gauges. if the temperature is different than what it should be then the refrigerant is contaminated.
They can evacuate the system, vacuum it and check for a vaccum leak at that time. If they do not loose any vacuum, then they can add refrigerant and this should cure the problem.
You will also have to figure out, how much you want to spend before you call it quits and buy a new one.
If you decide to buy another one, contact your electric company, alot of times they will offer rebates on new equipment. Also check for tax deductions on buying more effecient equipment. Depending on what you buy can get you a 30 % tax write off. But I am not sure on it. I hope that I have helped you._Ron
First question. Why couldn't you hook the high side up. Is it do to the high side hookup(schrader valve) blowing refrigerant out, when you were taking the cap loose?
Second question. If it is leaking, how much to repair it. Because from what I have heard you can't tell how the unit is running with out reading the high side gauge.
Third question. Do you think that maybe the condensor fan motor might be going bad?
Forth question. Why is it that last year the A/C was working good and this year it isn't keeping up with the heat? ( Be nice asking this question, you are asking them for their opinion.)
Fifth question. Do you remember what the low side pressure was. (the normal on a hot day, with the house at 75 degrees should be between 65 and 78 pounds of pressure. This is also dependent on the effeciency of the unit.)
Side note on pressures. The high side is dependent on outside temperature, as the temperature rises outside so should the pressure. this can be as much as forty to fifty pounds difference. The low side pressure is dependent on inside the house temperature. The warmer the house the higher the pressure. But only in small amounts. such as two to five pounds of pressure.
One thing that you can try, is during the heat of the day, put your thermometer in the outlet and measure the temperature. Then have someone read it while you spray water on the outside coil( the one exposed to the air). If the temperature of the outlet air changes significantly, then the condensor coil or the compressor or both are not operating very well.
The last question and the worst one of all. How much will it cost to replace the unit.
Over the years I have seen units fail over a years time, the signs are usually they just quit cooling, The compressor start making unusual noises and just is not working right. They have small valves in them(usually reed valves) that get bent or do not seal against the head anymore. The pistons are leaking by. But the only way to tell is by hooking up the high side on things like that to see the pressures.
Another thing that they can look at is to check to see if the refrigerant is contaminated or has noncondensibles( a big word meaning that the refrigerant has moisture of dirt in it that doesn't let it make a good liquid). they can do that by turning the unit off for a while and hook up the low side gauge. If the standing pressure doesn't change anymore, they can compare the pressure temparature to a refrigerant temperature chart. Usually built into the gauges. if the temperature is different than what it should be then the refrigerant is contaminated.
They can evacuate the system, vacuum it and check for a vaccum leak at that time. If they do not loose any vacuum, then they can add refrigerant and this should cure the problem.
You will also have to figure out, how much you want to spend before you call it quits and buy a new one.
If you decide to buy another one, contact your electric company, alot of times they will offer rebates on new equipment. Also check for tax deductions on buying more effecient equipment. Depending on what you buy can get you a 30 % tax write off. But I am not sure on it. I hope that I have helped you._Ron
Ron N
Well-Known Member
Aaron, I agree about the pride of workmanship. If your going to take the time to charge someone, take the time to do it right.Soap bubbles are my first choice, the second is the halide torch. It can pinpoint a leak in a coil in a little wind that an expensive piece of junk electronic detector can't even sniff._Ron
Most AC freeze ups are caused by low refrigerant. Dirty units actually make the unit run hot, causing the units to cycle off or have a thermal shut down.
If they guy said it was due to dirty condensor, or low on refrigerant, then why did that not cure the problem and why didn't you get your money back???.
I treat home repairs the same as suto repairs. Tell them the problem, have them diagnose the problem and if you foollow his recommendations, that should fix the problem. If it does not fix the prblem, then you should not have to pay for his mis-diagnosis or inexperience. After all, he is supposed to be a professional.that you are paying a lot of money to fix somethng and expect it to be done right.
II also have a heat pump (I live in Texas) and don't know if you are aware that heat pump only last abouthalf as long as a standard AC unit becaus it runs all year, while an AC only will only be used during the summer months.
had a guy tell me the same thing about 3 years ago. He cleaned the unit...which it needed (I usually do that myself) and he said I have the wrong kind of filter in the unit causing too much drag on the air??? After he corrects all tha, the unit still does not work and he finds a bad control relay that is not cycling on the outside unit properly and causing the unit to shut down. $35 switch is replaced and the unit runs fine.....He did not charge me for the AC cleaning, and I agreed to pay for the new filter since it needed to be changed anyway.
...Rich
If they guy said it was due to dirty condensor, or low on refrigerant, then why did that not cure the problem and why didn't you get your money back???.
I treat home repairs the same as suto repairs. Tell them the problem, have them diagnose the problem and if you foollow his recommendations, that should fix the problem. If it does not fix the prblem, then you should not have to pay for his mis-diagnosis or inexperience. After all, he is supposed to be a professional.that you are paying a lot of money to fix somethng and expect it to be done right.
II also have a heat pump (I live in Texas) and don't know if you are aware that heat pump only last abouthalf as long as a standard AC unit becaus it runs all year, while an AC only will only be used during the summer months.
had a guy tell me the same thing about 3 years ago. He cleaned the unit...which it needed (I usually do that myself) and he said I have the wrong kind of filter in the unit causing too much drag on the air??? After he corrects all tha, the unit still does not work and he finds a bad control relay that is not cycling on the outside unit properly and causing the unit to shut down. $35 switch is replaced and the unit runs fine.....He did not charge me for the AC cleaning, and I agreed to pay for the new filter since it needed to be changed anyway.
...Rich
Ron N
Well-Known Member
Richard, To be more specific, it depends on which part is dirty.I think you are talking about the outside unit. If it is dirty it does cause it to run hot. If it is the inside unit, it will cause it to run colder and freeze the inside coil. This can cause ice all the way to the compressor. I do agree, if the technician does not fix the problem, you call him back and tell him that he didn't fix it. It shouldn't cost you extra. He told you the first time that he fixed it. If you had the wrong filter in it, such as an allergy free filter. He could have adjusted the refrigerant for it. Not sell you a less efficient filter._Ron
