Measuring A/C Temp Solved, sort of...

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On 6/2/2015 2:25 PM, Terry Coombs wrote:

The heat pump my friend Kevin had, was used by smokers. My professional cleaning did so good, you couldn't even smell the stink when I got done.
And, golly did it ever stink.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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On Tuesday, June 2, 2015 at 1:52:56 PM UTC-4, Boris wrote:

It's not exactly crap. You have an 18 year old furnace and an 18 year old AC. They both rely on the same blower and main controller board. When you're replacing the whole AC system, you're already at about 90% of the labor to replace the whole furnace. All that's left is to disconnect the gas line and the electric and chuck the old one out. Not many people are going to opt to replace most of an 18 year old system, but then leave and rely on the rest of the old equipment. And if they do it that way, then later the blower or the controller board fails, the installer has an unhappy customer. Eqpt cost, the furnace part is less than the cost of the AC part. And also if the furnace part needs to be replaced later, then you have more labor cost, because now you have to take apart the AC system again.
Your symptoms could be a dying compressor. IDK why it would cost $2500 to replace just a condenser. It sounds about 2X high to me. But I'm also not sure I'd put even that into an 18 year old AC system. The cost of $10K for a whole new system sounds several thousand too high to me. When I went out for quotes a few years ago, I was getting $7K - $9K for a 5 ton AC, 120K BTU furnace and that was in The Peoples Republic of NJ, which is one of the most expensive places. If you shop around, I'll bet you can do a lot better. Also, the fact that the tech had to call around, including the manufacturer to try to diagnose the problem, wouldn't leave me with so much confidence in them.
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trader_4 wrote:

New furnace will have more efficient blower, probably VS or X13 type DC motor driven blower which is whole lot more efficient than old PSC type AC motor.
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On 6/2/2015 2:59 PM, trader_4 wrote:

CA is total expensive, also. I'm astounded that the tech (and telephone tech support) could not diagnose some thing so obvious. Me, I'm a fat, balding old guy who is running out of teeth. I'm no one special, just a common sense retread (polyester belted with suspenders) who thinks in simple terms.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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I guess that the furnace is either gas or oil ?
The copper tubes that get cold are carring the 'freon'. If no one has explained how it works, here is a very quick explination. The compressor has a piston in it that compresses the gas to a liquid, then to the outside unit that air blows across it and takes away the heat. Then pipes it to the inside coils where the liquid goes through a small restriction in the pipe . There it absorbs heat from the air and causes the liquid to boil and turn into gas. This makes the coils feel cool.
Unless you have a heat pump that reversed the flow and the tubes inside get hot in the winter it has nothing to do whit the furnace, just uses the same blower and duct work.
I don't recall you saying what part of the country you are in. If in an area that does not get below 25 deg C very many days of the year, you may want to look at a heat pump. Cost should not be much more. If in a cold area of the country, then a heat pump will not be very efficent.
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Gas.

Nope. that reversed the flow and the tubes

Yes, that's what I've surmised.

Sacramento, CA. high 90's to low 30's If in

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I put in 25 deg C, should have been F. If it never got below 25 deg C you probably would never need heat..
You may want to look at a heat pump. It probably won't cost much more and may be less expensive to run than the gas for heat.
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On 6/2/2015 1:16 PM, Boris wrote:

Hey, tell you want. If you decide to replace the entire unit, let me know what the quote is. I'll fly out have my tools shipped via ground, and do the job for much less than the replacement cost.
And visit my uncle in LA while I'm out.
I can provide at least one reference, fellow I did work for about a year ago. He bought a trailer and heat pump. I drove to South Carolina and serviced his system. Runs fine now, and even shocked the #### out of the seller (who made my friend sign an statement that the heat pump was totally beyond repair).
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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On 6/2/2015 12:24 PM, Boris wrote:

Have the fins been properly cleaned? That would be my first step. They lose efficiency when cruded up. There is a cleaner made just for that purpose.
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wrote:

I like to match my date's lipstick with the color of my car, but it doesn't make the car run any better.

I don't know enough to comment on the compressor but as you know, the furnace doesn't use freon. It's just their way of trying to get you to spend more. Do techs get a commission when customers spend money? At least more money than a simple repair? Probably.
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wrote:

I agree with the others in saying that the furnace/air handler do not necessarily need to be replaced. However, don't confuse the furnace/air handler with the inside part of the air conditioner - the evaperator coil. Those are commonly replaced when a new outside unit is installed.
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On 6/2/15 12:24 PM, Boris wrote:

I'd check the temperature of the tube taking the liquid freon out of the compressor unit with an infrared thermometer. The copper probably won't give you a good reading, but if you wrap it with electrical tape, you should be able to get a good IR reading from the tape.
If it's not much above the outdoor air temperature, the compressor radiator isn't the problem.
I'd be interested in the temperature between the compressor and the radiator. First, I'd google to try to find out what a reasonable temperature is.
On my compressor, I don't think I could get an IR reading with the compressor running. I'd tape the probe from an indoor-outdoor thermometer to the tube. (Actually, I'd use the probe that came with my multimeter because it's smaller.) I'd tape insulating material over it to keep air from cooling the probe.
If the freon going into the radiator is abnormally hot but it's good coming out, I'd suspect a restriction on the flow of freon somewhere in the system. I'm vague about air conditioning, but I believe there's a thermostatic valve on the evaporator. If it malfunctioned, I imagine that restriction could be severe enough to overheat your compressor.
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On 6/2/15 3:23 PM, J Burns wrote:

Come to think of it, I wouldn't bother to check the temperature of the tube coming out of the compressor. If the condenser is cooling properly and the compressor is too hot, I'd suspect a malfunction in a valve at the evaporator.
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On 6/2/15 3:33 PM, J Burns wrote:

How about your drier? Many times, a drier will last the life of the system, but not always. They can get clogged.
I've read that the water in freon can cause all kinds of problems. I wonder if one problem could be a buildup of ice in the valve on the evaporator that separates the high side from the low side.
When the compressor wasn't running, the ice would melt. Then the air conditioner would run normally until a buildup of ice blocked the valve. You'd lose your cooling, and I imagine the compressor would overheat.
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On 6/2/2015 4:12 PM, J Burns wrote:

With water in the system, it is very possible to block the flow of refrigerant. In that case, the refrigerant stops absorbing heat, and the compressor has much less work to do. So, no, doesn't over heat.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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On 6/2/2015 3:23 PM, J Burns wrote:

Some have TXV and some have orifice (which for some reason is called a piston). If there is a restriction, the house won't cool well, but also there will be much less heat coming into the compressor. I doubt that's the problem.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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On 6/2/15 10:46 PM, Stormin Mormon wrote:

This page says a blockage will overheat the compressor.
<http://www.achrnews.com/articles/91098-reasons-behind-compressor-overheating
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On 6/2/2015 11:35 PM, J Burns wrote:

Says it's one of several possible causes. The article said that low suction pressure can cause a higher than normal pressure ratio. What I've found, is that restrictions cause lower discharge pressure and temperature.
If you read down two paragraphs, or maybe three, you'll find my diagnosis listed.
- . Christopher A. Young learn more about Jesus . www.lds.org . .
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That doesn't sound like all that hot a temperature for teh compressor to me. But I'm just guessing. I know I've had compressors in the past that would run all day long and be so hot that you couldn't touch them without getting burned but they never stopped running. So maybe it's overheat protection is a little too touchy.
I also got the impression from my AC guy that part of having a proper amount of refrigerant in the system is so that there is a certain amount of COLD refrigerant that for whatever reason trickles into the compressor to keep it from getting too hot. I got the impression that a low charge meant there wasn't enough of the "left over cold refrigerant" to cool down the compressor and that could make the compressor run hot. Sooooo... if there is any truth to that I would hypothesize that if you were to have your AC guy shove some additional "freon" into your system, whether he thinks it needs it or not, that it might make the compressor run cooler and solve your problem.
wrote:

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Yes, the tech did say that freon also cools the compressor. He checked it, and said it was fine. But...I had to ask him to check it. This company, SierraPacific (Rancho Cordova, CA), is the company that installed solar pool heat on my dad's roof 30 years ago. It's been maintained and keeps the pool between 84 and 90 in the summer. I've got an annual maintenance contract with them. With the a/c, my dad never had a contract, and would just call any old company when service was needed. I did add to the solar contract, an HVAC maintenance contract last month, and they have been very responsive when I call them out. The last two visits were about 2 hours each doing diagnostics, with no charge. They come highly rated locally, and on Angie's List (for what it's worth),and drive around in expensive, well stocked vans. However, they are always trying to sell something.
I'm thinking I should clean the compressor fins and then see what happens. If no better, I may call another company out for a second opinion.
As you can tell, there's a pool at this house. All this reminds me of last year when I hired a pool guy (I live two hours away in the S.F. Peninsula) to take care of the pool. The first thing he told me was I needed a new sand filter. Funny, it always worked well, even though the zeo-sand was 8 year old on a ten year life span. He wanted $1000 to put in a new filter. I knew nothing about pool maintenance (I'd rather not have a pool, but this is Sacramento), but I taught myself, and cleaned up the filter for about $50. Works great now.
But I digress...
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