HVAC Experts? Help Needed.
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From: The Bluegrass State
Rockpick,
No, i don't see a reason your coils should have that much oxidation. Maybe here in Tampa on the coast near saltwater, but gotta figure not much sea water near Kentucky. That is part of the problem, i would have to think, with heat rejection being a little out of wack with the rusty coils, which also if they are not leaking now, will be soon enough. Can't believe you had that much of the coil blocked with insulation. That should have had an effect on the pressure on the liquid and suction lines. Call the slack-jaw back that hosed it all up and show him the crap you pulled out and pictures, and don't let him out of the attic until it's fixed!
Good luck, brother!
No, i don't see a reason your coils should have that much oxidation. Maybe here in Tampa on the coast near saltwater, but gotta figure not much sea water near Kentucky. That is part of the problem, i would have to think, with heat rejection being a little out of wack with the rusty coils, which also if they are not leaking now, will be soon enough. Can't believe you had that much of the coil blocked with insulation. That should have had an effect on the pressure on the liquid and suction lines. Call the slack-jaw back that hosed it all up and show him the crap you pulled out and pictures, and don't let him out of the attic until it's fixed!
Good luck, brother!
You're confirming my hunch on the oxidation around the coils... I thought it was excessive as well. It actually was to the point that I could take a fingernail and flake off metal (as you can see in the drain pan beneath the evaporator). Most of the gunk in the pan actually had come off on its own though...
I have a phone call in to them... no return phone call as of yet.
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An update...
They didn't call back - and I got ultra busy toward the end of the day so, guess who is going to call back in the morning?
Anyway, while doing more research on this tonight... here's my thought...
My system is now OVER charged with refrigerant.
I base this diagnosis on THIS Q&A
According to the response, a lightly cooling system could very well be due to an OVER charged system. In my mind, this makes sense because the guy put in more refrigerant based upon low pressure reading. He says that a 'poor technician' will simply put more refrigerant into the system rather than diagnosing what is causing the low pressure. Lastly, within the read, it makes mention that low air flow across the internal coil (located within the plenum) would cause low pressure....
So, clogged evaporator with insulation = low air flow = low pressure readings at the condenser = technician wanting to put more refrigerant in the system.
Thoughts?
They didn't call back - and I got ultra busy toward the end of the day so, guess who is going to call back in the morning?
Anyway, while doing more research on this tonight... here's my thought...
My system is now OVER charged with refrigerant.
I base this diagnosis on THIS Q&A
According to the response, a lightly cooling system could very well be due to an OVER charged system. In my mind, this makes sense because the guy put in more refrigerant based upon low pressure reading. He says that a 'poor technician' will simply put more refrigerant into the system rather than diagnosing what is causing the low pressure. Lastly, within the read, it makes mention that low air flow across the internal coil (located within the plenum) would cause low pressure....
So, clogged evaporator with insulation = low air flow = low pressure readings at the condenser = technician wanting to put more refrigerant in the system.
Thoughts?
Last edited by Rockpick; Jun 16, 2008 at 10:42 PM.
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From: S.E. Michigan
Wow. I kinda thought you would have to open it up all the way to confirm the problem. I would get a good well known reputitable hvac company and have them document everything you found. I would stop at nothing short of completely replacing everything, if the system has been overcharged and overworked. I would have all the ductwork professionally cleaned and then i would get a hold of the builder/insulating company and have a long talk. Save the insulation that was inside the unit, and have it tested for Black Mold. Has anyone been sick, or sinus infections? You better make sure it's done right. Contact an attorney.
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I'm going to attempt to play civil and adult-like through this but, I refuse to allow a few things to not happen with this situation. I feel very strongly - however, cannot document with and to completion - that the return air duct was never zip tied or properly secured. This was the root of the problem and, as such, should be the event that has caused the problem as a whole. Ultimately, it is also what has caused me to invest my own coin into the system without proper diagnosis from the HVAC company.
I know that it sometimes takes drastic measures to line out a problem but, over the past 4+ years in this house, it's never been quite right in my head. Now I know why...
As an update, the HVAC Service Manager and I played phone tag all day but never connected. I'm being civil but have tipped my cards to him slightly to let him know why I'm calling.... more later.
Lastly, as a supporting tidbit of information, I asked a few questions on allexperts.com... here is the response that I got from a guy who has been in HVAC for 25+ years...
I think that speaks volumes...
Thanks for the continued ideas, thoughts, and help!
-RP-
I know that it sometimes takes drastic measures to line out a problem but, over the past 4+ years in this house, it's never been quite right in my head. Now I know why...
As an update, the HVAC Service Manager and I played phone tag all day but never connected. I'm being civil but have tipped my cards to him slightly to let him know why I'm calling.... more later.
Lastly, as a supporting tidbit of information, I asked a few questions on allexperts.com... here is the response that I got from a guy who has been in HVAC for 25+ years...
Hello Brad. It sure makes you wonder what the inspectors look at to give a final inspection approval on an installation doesn't it. Lets start with #4 first. With the insulation attached to the coil, the coil held moisure under it and caused it to begin rusting. Unless it develops a leak, it should be fine for some years. #3, actually an overcharged system will have less condensation as the evaporation process in the coil is not as it should be. #2, definitely! I will explain further. #1, yes.
A clogged indoor coil will give pressure readings indicating the system is low on refrigerant. Low air flow with a clogged coil will give you the false readings. Adding to the charge will directly affect the refrigerant evaporation process in the coil. On a set of gauges, the low side pressure has a secondary gauge that will show the typical temperature of the coil at a set pressure. Higher pressures result in higher temperatures of the coil. Two simple tests without gauges is checking by feel the outdoor lines at the outdoor unit. The large line should be very cool and sweating, the small line should be very warm. Also, check with a good thermometer at the filter the return air temperature, then take a reading at one of the supply vents that is closest to the indoor fan section. The difference should be close to 20 degrees. I am certain with the clean coil, the unit is overcharged now. Get the pressures checked and recheck all of the ducts, supply and return to ensure a tight fit at all fittings.
Let me know how it goes Brad, thanks J
A clogged indoor coil will give pressure readings indicating the system is low on refrigerant. Low air flow with a clogged coil will give you the false readings. Adding to the charge will directly affect the refrigerant evaporation process in the coil. On a set of gauges, the low side pressure has a secondary gauge that will show the typical temperature of the coil at a set pressure. Higher pressures result in higher temperatures of the coil. Two simple tests without gauges is checking by feel the outdoor lines at the outdoor unit. The large line should be very cool and sweating, the small line should be very warm. Also, check with a good thermometer at the filter the return air temperature, then take a reading at one of the supply vents that is closest to the indoor fan section. The difference should be close to 20 degrees. I am certain with the clean coil, the unit is overcharged now. Get the pressures checked and recheck all of the ducts, supply and return to ensure a tight fit at all fittings.
Let me know how it goes Brad, thanks J
Thanks for the continued ideas, thoughts, and help!
-RP-
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From: >wwOwww<
Rp
Don't atempt to be civil. Pretend you're playing poker.
Get that out of your mind.
In customer relations if they can not **** you off they have no recourse...
If they can't **** you off you win.
Insist on a new evaperator coil also, that thing has been frozen solid so many times, You stated 4 summers.
Don't atempt to be civil. Pretend you're playing poker.
Get that out of your mind.
In customer relations if they can not **** you off they have no recourse...
If they can't **** you off you win.
Insist on a new evaperator coil also, that thing has been frozen solid so many times, You stated 4 summers.
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From: North Huntingdon,Pa.
my biz has been swamped rp-
1-you should have a 16-20 degree temp drop across the coil
-it appears that the front of the evap coil is rusted through?this is bypassing your coil-did they charge the unit by superheat or subcooling method?did the unit cool in previous years or has this always happened?please shoot me an email openclasspro@verizon.net-phil
1-you should have a 16-20 degree temp drop across the coil
-it appears that the front of the evap coil is rusted through?this is bypassing your coil-did they charge the unit by superheat or subcooling method?did the unit cool in previous years or has this always happened?please shoot me an email openclasspro@verizon.net-phil
