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Old 07-22-2013, 11:40 AM   #1
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Is NOW a good time to replace my 1986 AC?


We have a 4 BR single family house with a single Lennox 1-ton central AC from 1986. We have American Home Shield home warranty. Including today, it has been topped off with refrigerant 2 or 3 times in the four years we've been in the house. When it gets close to 100 degrees outside the AC can't keep up and I realize something's wrong. The air coming out of the vents was 71 providing about a 7 degree difference that day. After the fill, air was 62 degrees at the same vent today with 75 degrees at the intake.

HVAC techs have not been able to find the leak in the past. The guy from today found the leak in the evap coil with an electronic beeping detector. He said the evap coil needs to be replaced. Work order says, "System SH @45 UNSAT." Not sure what that means.

I am meeting their manager this afternoon to get an estimate and options including replacing just the coil and the whole system. Last year when my heater control board went out we discussed replacing our gas furnace heater with a more efficient unit but have not done anything about it. IIRC, the natural gas furnace is in the 60% efficiency range and approx 20 years old.

I think based on the age of the equipment now is probably a good time to replace everything. Is it? Has technology improved such that we'll save a noticeable amount on our electric bill with new equipment? I assume most or all of the cost will be mine.

Another issue is that we would like to redo our back yard patio and make it a nice place to hang out and host parties but you cannot have a conversation on the patio because the AC is so loud. The condenser unit sits on the patio right outside the family room window and disturbs our TV watching. Our windows are probably original (1965). I'm sure it was placed there because it is the shortest run to the indoor air handler in the basement. I'd like to move the condenser unit to the other (north) side of the house where we won't have to hear it or see it. It'll also be in the shade, if that matters. BUT it's about 50 feet further away from the air handler. Assuming the new lines would be run inside, the basement is partially finished and partially unfinished. The lines would have to run from the unfinished furnace room, across the finished ceiling about 20 feet and then into a small unfinished storage room about 8 ft wide and then across a crawl space with a concrete floor about 20 ft to the new location. How much more will this cost me?

Also, it's always warmer on the second floor during the cooling season and colder on the second floor during the winter. I try to balance it by closing off certain air vents but I still can't get the temps balanced. Is it a good idea to put the new unit in the attic? We have three separate attics in our house since our house has a one story section, a two story section, and a garage.


Last edited by mystic_cobra; 07-22-2013 at 11:49 AM.
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Old 07-22-2013, 12:16 PM   #2
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Is NOW a good time to replace my 1986 AC?


You should replace it for several reasons.

1) The coil is obsolete and yours is old school 8 SEER and the replacement is 13 SEER so it is a gross mismatch and won't work properly

2) The compressor is like a 1986 car engine with a ton of miles on it and quite worn out and probably only pumping about 85% of a new one.

the new units are a lot quieter unless you buy the cheap builders grade. there are 3 tiers: builders, regular and deluxe and they get a LOT quieter at the top end. A Lennox XC series 14 and higher you can run and have a conversation beside it w/o raising your voice. 50 feet is the maximum length of line w/o having to upsize it and that gets very expensive and is not recommended anyway. you would have to get prices from a dealer. the newer furnaces have stronger fans if you get an ECM motor so that will help push air upstairs. you need a EXPERIENCED high quality contractor to assess the ductwork to see if it needs upsizing or improving. you really get what you pay for price wise so stay away from the fly by night ers.

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Old 07-22-2013, 12:40 PM   #3
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Is NOW a good time to replace my 1986 AC?


Thanks for the reply. The contractor that AHS uses in my area has been in business 80 years and BBB accredited for 10 years. No rating listed, not sure what that means.

If I get a new AC unit I guess I'll need a whole new air handler and furnace, too? Time to get that whole house humidifier while I'm at it?
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Old 07-22-2013, 01:08 PM   #4
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Is NOW a good time to replace my 1986 AC?


I have a tough time believing that a 20 year old gas furnace is operating at 60% efficiency. But be that as it may, if you have been planning on replacing everything, now is a good time to do it. Since you are using gas I would look at a 90% + furnace. The overall savings from that alone would help pay back the cost of replacement.
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Old 07-22-2013, 01:56 PM   #5
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Is NOW a good time to replace my 1986 AC?


That 60% number came from the repairman so maybe he was trying to help sell me a new unit. I will check the model numbers and verify with my own research. But yes, we have natural gas in the house.
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Old 07-22-2013, 02:58 PM   #6
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Is NOW a good time to replace my 1986 AC?


Quote:
Originally Posted by mystic_cobra
That 60% number came from the repairman so maybe he was trying to help sell me a new unit. I will check the model numbers and verify with my own research. But yes, we have natural gas in the house.
No, he is trying to make money to pay bills. It is your money, look around. Lennox's Armstrong air line is good and outdoor units are quiet. Only difference is that it is Battleship gray, not Lennox Green on the equipment exterior.
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Old 07-22-2013, 03:02 PM   #7
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Is NOW a good time to replace my 1986 AC?


there are 2 types of efficiency, combustion and AFUE which you should Google. that actually tells you how much that old furnace costs to heat your house vs a higher efficiency unit. more like the Energuide stickers they put on firidges and appliances. combustion efficiency is just the burners not the operating cost of reheating air you bring in the house for combustion and leakage up the chimney. have none of that with a sealed combustion 90+ efficiency unit. I would do the whole pkg as you get a MUCH better price and everything fits better with the tin work and wiring etc than doing it piecemeal. some of the contractors who do home warranty work may be good with their regular work. the warranty jobs don't pay them very well or turn out well a lot of the time. if he is working for himself then I would not worry.
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Old 07-22-2013, 03:02 PM   #8
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Is NOW a good time to replace my 1986 AC?


As for the SH @ 45, they are talking about Super Heat. Unless you an gind the books on the equipment, it will state what Super Heat should be.

As for these home warranties, majority are not worth the paper they are on, and will always try to get you into the cheapest equipment for most of them.
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Old 07-22-2013, 03:19 PM   #9
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Is NOW a good time to replace my 1986 AC?


Do you have a natural gas water heater and does it vent through the same chimney flue as your furnace?
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Old 07-22-2013, 04:28 PM   #10
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Is NOW a good time to replace my 1986 AC?


Sounds like you could really benefit from a replacement. As for NOW being the best time I'd say if your system is working OK you might want to wait for a nice early fall week to have it done so you don't need to swelter or freeze while they work, even if they can do it in one day. Also, depending on your house and floor plan, running the pvc vent and intake pipes for a high efficiency furnace may be difficult and costly... or not. Just something to consider for the bids.
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Old 07-22-2013, 04:35 PM   #11
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Is NOW a good time to replace my 1986 AC?


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No, he is trying to make money to pay bills. It is your money, look around. Lennox's Armstrong air line is good and outdoor units are quiet. Only difference is that it is Battleship gray, not Lennox Green on the equipment exterior.
I understand that everyone has to make money to make a living. I will get some other estimates before I decide. I'll monitor the air temp daily to see if it is a fast leak or or a slow leak. It might go another year for all I know.
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Old 07-22-2013, 04:42 PM   #12
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Is NOW a good time to replace my 1986 AC?


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Do you have a natural gas water heater and does it vent through the same chimney flue as your furnace?
Yes, I have a natural gas water heater next to the furnace and it vents into the wall at the base of my chimney just like my furnace.

We talked about that today when the Manager was out this afternoon. He explained to me about adding the liner if they replace the furnace and the moisture in the chimney. I had no idea.
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Old 07-22-2013, 04:44 PM   #13
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Sounds like you could really benefit from a replacement. As for NOW being the best time I'd say if your system is working OK you might want to wait for a nice early fall week to have it done so you don't need to swelter or freeze while they work, even if they can do it in one day. Also, depending on your house and floor plan, running the pvc vent and intake pipes for a high efficiency furnace may be difficult and costly... or not. Just something to consider for the bids.
I don't remember him mentioning pvc vent/intake. My system only pulls air from inside the house. He did mention that the whole thing can be done in a day but I can see waiting a while til off-peak time for the comfort of all involved.
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Old 07-22-2013, 04:53 PM   #14
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Is NOW a good time to replace my 1986 AC?


He said the warranty company is likely going to offer a credit for the evap coil only of ~$300-400 and that the labor will be my cost for installation (~$400-800). He is going to give me a written estimate and include that basic option along with options to upgrade the whole AC (in and out) and a third option to include the complete AC and furnace. I also asked about moving the outside AC unit off the patio to the shady side of the house and quoted that at about $35 per foot for lines and electrical.

He explained that I won't get much, if any improvement in efficiency or cooling costs by replacing just the AC as the furnace blower is more important in that regard.

Does all of this sound right? He said their new furnace would be a programmable unit from Amana that they program. He also suggested the 14 SEER as it has a lifetime warranty. Said it gets you quicker repair service (2-3 days vs 10-30).

Who wants to bid on my job?
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Old 07-22-2013, 05:24 PM   #15
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As for these home warranties, majority are not worth the paper they are on, and will always try to get you into the cheapest equipment for most of them.
I'm still trying to wrap my head around the fact that the warranty company sent a technician who knows how to measure superheat and can find a leak.

I'd take whatever cash out I could get, maybe argue for more than the initial cash out offer (does the warranty say OP pays for installation and not the warranty company?). Then I'd start getting quotes for single fuel 95% furnace and A/C vs dual fuel 95% furnace and heat pump.
Maybe hire an energy audit before getting the quotes so you know how big the equipment should be.

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