New Unit Is Costing Me A Fortune!


  #1  
Old 09-15-02, 12:08 PM
tgibson
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New Unit Is Costing Me A Fortune!

Fellows:

About a month ago, I had my old Bryant Model #568CJ036 replaced because the compressor had gone out. This unit was probably at most a 9 Seer unit because it is the original unit when the house was build about 17 Years ago. I was told this is a 3 ton unit.

The air conditioning fellow came out and replaced the outside unit with a Goodman 10 Seer unit. He also had to replace a small valve like part that is connected to the coils (I assume) in the attic part of the blower. He said this small part was clogged up and preventing freon flow, which might explain why the compressor in the Bryant went out. Who knows.

What I do know is my first Electric bill went from $180 a month to $420 a month!!! I liked to have died!! I have both units on a programmable thermostat which I have not changed. I know now that this NEW unit is having to run a whole lot more than my old one. I have been monitoring my Electric meter outside on a daily basis to see how much power I am using on a daily basis. I am now using about 110 KW of electricty on a daily basis as apposed to the 60-70 KW I used to use.

I am puzzled as to how a new unit is LESS enery efficient than my old unit?

What could be the problem? When I got my first bill about 3 weeks ago, I called the AC guy out immediately. He added freon and thats it. But it has not heped the situation out. I am now having to leave the unit set at 78 degrees insted of a cool 73 like I used to have it and I am paying the same price in electricty!!!

Is it possible that the small deviced he replaced upstaris is causing this problem? What is its function and should have lots of condensation on it? I never notice the old one and how it functioned.

One final note that makes me completly upset. When the new unit was installed, the compressor did not kick on. He had to use some kind of capacitor/jump start thing to get it running. He said that new compressor are like this, they just need a few jump starts to get them running because they are new. Could it be that maybe the compressor is sticking and not running as much or comming on immediately. Is this true or do I have a defective unit?

Any ideas? Please help me! I have already used 2300KW electrity this month (21 days) and I normally use 1800-2000KW electricty in a 30-31 day span. Like I said eariler, I have had to raise that units theromstat to 78 to achieve this result. Otherwise I might have already used 4000KW electricity!

Thanks,
Todd Gibson
 
  #2  
Old 09-15-02, 01:47 PM
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sounds like

he replaced the metrering device that regulates the refrigerant flow into the evap coil. even so, the charge should not have been low so quick. you did not mention replacing the coil, if it is as old as the original o/d unit, you possibly have a leak. as for the part he put on outside, it is likely a "hard start kit", which increases the voltage during start up, thereby reducing the amperage, and giving the compressor an extra kick. it is also called a torque multiplier. have seen this happen before, as sometimes new compressors are "tight" and require the extra jolt. since you say this is a goodman, basically bottom of the line unit, i expect you will have even more problems in the future. these units are notorious for losing the capacitor after just a few years, and generally are good for 7 to 11 years. i would raise a stink, get those guys back out there, preferably the service manager.
 
  #3  
Old 09-15-02, 04:18 PM
Nominal
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Also check

up in the attic. If he had to go up in the attic to replace metering device, maybe it is possible that he accidently knock off a duct somewhere or left a door off, causing unit to pull air from attic. It is also possible that if the metering device was restricted, maybe he did not get all of the trash out and it is restricted again.
 
  #4  
Old 09-15-02, 04:38 PM
tgibson
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advise

Yes.. the metering devicec was the part replaced upstairs. You see, the unit was covered under my home warrenty. That is why a Goodman was put in. I will get him to come out again this week and see if there is a leak in the coils. I did notice that the duct box does not fit properly. However, he did not have to open this to get to the metrering device. The metering device sticks out the side of the duct box on my unit. If pulling air from the attic is the problem, then the old unit that was replaced should have had the same problems.

He did not leave the hard start kit in the unit. He was going to do that when he originally installed the unit, but the compressor finally kicked on and he said I did not need it. I would not think a brand new unit would need this kind of kit you know what I mean.

When the home was inspected last July when I purchased the house, the Temperature Differential was 15 degrees. What does that mean and how can I tell if the new unit is putting out the same? The a/c guy did come inside the house and took a reading of the temperature comming out of the vents. How can I get this differential from the temperature reading from the vents. And what should this differential be. Would this be a way of determining if the unit is not functioning as well as the older unit?

Thanks for all of your suggestions and help,
Todd Gibson
 
  #5  
Old 09-15-02, 05:21 PM
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no suprise there

goodman i$ the unit of choice for the home warranty guys. we have not done their work for over 10 years because they want the cheapest way out with no concern for the customer. in my opinion if the unit needed the hard start once it will again. they are cheap, less than one hour's wage for a tech. as for temp difference, check inlet temp at furnace vs. outlet temp also at furnace. this will tell you what the unit is actually doing. if you check at the registers (grilles) you can easily get false readings as heat may be gained through the duct system. look for 16 to 20 degree differential.
 
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Old 09-15-02, 06:47 PM
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Angry

Could be the tech knocked a duct loose or crushed one, while he was installing the TXV. I have seen TXV's installed and the piston was left in, creating additional restriction and high pressure. This would require the compressor to pump harder. Might explain why a start kit was needed. I sure would like to know what the amp draw is.

Another obvious thing to check out, the electric elements could be operating at the same time the a/c does. Was a new thermostat installed?

I agree with hvac4u, get the boss out there.
 

Last edited by 410a; 09-16-02 at 07:47 AM.
  #7  
Old 09-18-02, 04:26 PM
tgibson
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Repair Man's Findings

Well, I got a different A/C company to come out and do some research on the problem.

He said that there might be two things that is causing this..

#1: The condenser unit is a 3 ton while the coils are 3.5 ton.
#2: The old Bryant unit was a bigger unit than the replacment.

I did not think that the physical size of the condenser units made a difference. The Goodman is about 1/4 the physical size of the old Bryant unit.

He added some more Freon and is putting in a work order to replace the coils in the upstairs portion of the unit. I wish he would just change out that 3 ton and replace it with a 3.5 ton condenser unit to match the existing coils.

I just wonder if that Bryant unit was modified to match 3.5 ton coils. The model # shows that the old unit was a 3 ton. I don't know. I just know that the problem is still not solved and it's costing me on a daily basis.

He also stated that they should have had a bigger condenser put in because of the area it is cooling.

Again, no answer to the question, how come a 17 year old unit is out permorming a brand new unit.

Any takers?

Thanks,
Todd Gibson
 
  #8  
Old 09-18-02, 04:30 PM
tgibson
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Forgot one thing...

Ohh yea... he added a Kickstart device to the compressor. And the Temperature Diff after adding the Freon is only 14 degrees.

Side note: the compressor when running is only pulling 14.0-14.5 amps.

Thanks,
Todd Gibson
 
  #9  
Old 09-18-02, 05:47 PM
bigjohn
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See a pattern here? Unit is changed out, not working so well, guy comes and adds freon. Guy #2 comes out and adds freon. WHY? Why are these guys adding refrigerant? Is it a leak or are they seeing low suction pressure? I would like to know more about the metering device. Do you if it is a Thermostatic expansion valve or a piston? [fixed orifice] I'm thinking that a 17 year old Bryant probably had cap tubes and when the metering device change was made, the guy is trying to use the cap tubes as distribution tubes. This would cause excessive pressure drop at the metering device and not feed refrigerant to the cooling coil prorperly. Todd- go outside and feel the larger of the two pipes at the outdoor unit when it's running. Warm, cool or cold? Question- compressor is drawing 14.0 to 14.5 amps, compared to what? What is the full load amperage rating of the compressor? [look on the unit nameplate]The 14 degree TD is too low. I suggest that you stop the replacement of the indoor coil, call the home warranty co. and ***** that the repair doesn't work. Don't get involved in a technical argument with them, just compalin that the repair doesn't cool as well as the old unit did and you want it rectified.
 
  #10  
Old 09-18-02, 05:50 PM
Diceman
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You got screwed

Goodman sucks, good luck, you're gonna need it.
 
  #11  
Old 09-18-02, 11:09 PM
lynn comstock
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What a mess.

1) Your old unit had a 3-ton model number.
2) The factories list many coil sizes as approved matchups to a given outdoor unit. There is nothing wrong with a 3.5-ton coil matched to a 3-ton condensor. All manufacturers allow that. It gives a higher SEER rating (but less humidity removal).
3) The techs you have had are groping for answers. They just don't KNOW. Gropers change parts and equipment as a solution.
4) Adding gas is considered a magic bullet by many techs. (When they don't know what else to do.) There may NOT be a leak and your system may be OVERCHARGED with refrigerant causing high pressures, poor performance and high electicity use.
5) If the installing tech did not evacuate the system to remove the air that gets into an open system, the results are like 4).
6) Both 4) and 5) may be going on.
7) Many of the suggestions given before are valid as well.
8) You need to find a really competent tech.
*******************************
The most common problems that cause excessive running and power consumption:
1) Dirty air filter.
2) Dirty indoor coil.
3) Dirty outdoor coil.
4) Low refrigerant charge.
5) Excess refrigerant charge.
6) Disconnected or leaking ducts.
7) Damaged compressor.

A WORD OF CAUTION: you need an EPA license to even put gauges on your own AC. The minimum fine is $10,000.

ASK a Tech get ALL of the following nine items of DATA and tell you his opinion of the problem and solution:

Outdoor ambient- condenser air entering temperature
Outdoor condenser air leaving temperature
Return air dry bulb temperature- air temperature entering the indoor coil
Supply air temperature- air temperature leaving the indoor coil
The wet bulb temperature of the return air
Head (high side) pressure
Liquid line temperature (Small line at the outdoor unit)
Back (low side) pressure
Suction line temperature (Big line at the outdoor unit)

If the tech doesn't understand what you are asking for or tells you that he doesn't need the requested information because of his experience, don't have him/her do anything. Keep looking for a tech who understands your request and agrees that this information is important to reach a proper diagnosis.

THE UNIT MUST BE IN CONTINUOUS OPERATION FOR 12 MINUTES AND THE DATA COLLECTED IN A FIVE-MINUTE TIME SPAN. To get the wet bulb temperature, wrap a small wet tissue around the sensor or bulb and hold in the return air stream for 90 seconds. I recommend that you watch the data collection process. Ask questions to learn everything you can about why this information is important.

With that DATA, I can diagnose the proper or improper operation of your equipment and tell you what problem is or isn't. Without that hard information, all we can do is guess.
 
 

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