Home Cental AC died

[wesalexleft]

I know this isnt "garage" related, but just wanted to get some cost opinions. Our 15 y/o central AC quit...compressor shorted to ground. It's an R-22 system, 5 ton, in a two story house. I have a "guy" who's always treated me well on repairs, and he's quoted me a new system for $7800.00 which includes a Lennox 14 SEER 5 ton unit, new evap coils, etc, and a new two stage 110K gas furnace. Does this sound about right installed? The house, built in the 70's is set up for one unit only and we both agreed it would be very tough(expensive) to convert it to a two unit AC system. In addition, I have a 7/8" suction line which kind of prohibits the newer high SEER units with over 1" suction lines. the lineset runs from the attic of the two story to outside and currently has a run over over 30' I'd guess. The current furnace it at least 15 y/o as well, so I'm guessing it wouldn't be much longer before I had a cracked heat exchanger, so having the whole thing priced.

If location is a factor, we're in the southeast...Memphis, TN area. He's been great as far as coming out to take a look the day of the failure, checking it out, and said he could start work on the new system tomorrow.

Thanks,

 

[Falcon67]

I had a rough SWAG from the company that just serviced our HVAC unit - a 3.5T heat pump would be in the 6K~8K range more or less. Not a lot of help, but something. I figure I could DIY the thing for 50~70% of that cost, assuming I could get a company to even purge and service the system.

 

[Steevo]

That sounds pretty fair for the entire A/C & heat system.
We paid that much for the A/C portion alone when ours failed a few years ago.

 

[brewchief]

Which model furnace? Is it an 80% or 90%?

 

[EdT]

I replaced both systems in my house about four years ago and, after a lot of research, determined that financially, for me, the fancier, high efficiency units did not have a reasonable payback. I discussed it with my "guy" and he said that he would install whatever I wanted, but that he usually recommends the simpler systems with fewer control boards and all because they are more reliable and cheaper to fix. So, evaluate your operating costs and see what the payback looks like. I only spend a couple of bucks a day on cooling so there was not a lot to work with in the first place. Your situation may be different. Also, remember that the efficiencies are "up to" and under ideal conditions. Your mileage may vary. Also, I don't know what kickbacks are still available, but I think most of the government ones went away.

 

[wesalexleft]

He didn't specify on the furnace other than what I have, but I'm assuming its going to be an 80%. I agree about price vs simplicity. The super high efficiency models would have to be trouble free beyond their lifespan for them to pay in my 70's home. I've upgraded windows, etc, but there's only so much that can be recouped in this 80% humidity here.

 

[brewchief]

Lennox offers two 2 stage 80% furnaces, EL280 is a two stage 80% with a constant torque motor, SL280 is a two stage 80% with a variable speed motor, the SL280 can be used with the Lennox icomfort thermostat that will give remote access via wifi so you can check or adjust your system from a computor, tablet or smartphone from anywhere in the world. The icomfort stat can also provide advanced dehumidification control by slowing the blower speed of the furnace to allow the A/C to remove more moisture.

No matter what furnace I always recommend installing a good media filter, we use either the Lennox healthy climate or Aprilaire filters.

Price would be about right in my area, your area may vary.

 

[theoldwizard1]

2 stage furnaces are expensive. Check the price difference between that and a single stage. Same with infinitely variable speed blower motor.

 

[indyokie]

I'm in Oklahoma City, lived here with standard stuff for 7 years, and when I added on a room 5 years ago, I installed a 16 SEER A/C 96% Gas Furnace. House was built in 1983. 3-1/2 tons and I did 85% of the labor Your price looks right like the other guys stated. It was the single best thing I have added to the house. The comfort level is exceptional and yes, I knew it was more parts more to go wrong...but that wouldn't stop me from buying a new car, they all have boards, they all have fans. Payback ? If you can buy the better unit, It's quiet, it's clean, and it is comfortable. It's in the Summer when the house is +/- 2 degrees and can stay there all day - good stuff. I wish you well in your purchase. I replaced all of my ductwork to be more in line with the airflow for our new system. Returns in rooms that never had them- that makes a huge help as well- perhaps something you can do with the installer

 

[Dennis93]

Sounds about right. Have no clue what SWAG means, but good luck finding a company that will come purge, vacuum, and fill your system once you've installed it. If you do find one, they will probably charge you what you saved since you can't in any way really do that without the proper equipment and they know that.

Also 5 ton is HUGE, I imagine your house is 2700 sq ft or larger. Surprised they didn't make it 2 zone. But yes on average here around 2500 sq ft houses have a 3-3.5 ton and cost about 5500 and some change. Also depends on your attic and the access and overall pain in the **** factor. The only advantage you are really looking at now is that instead of replacing 2 systems at around 4500 a piece you are getting one replaced at 7800.

 

[wb2vsj]

FWIW - I stumbled across this the other day. Not sure how "accurate" it is. Just fill in the blanks and you'll get a quick estimate


http://www.charlottehvacguide.com/

 

[pop pop]

Wes, Brewchief has hit on something I feel is really important in humid climates. You, like me, live there. Get the variable speed air handler and humidistat. I did this 8 years ago when we replace our entire system (Carrier) and love the results. We picked the middle range of the three available, not the most elaborate, but don't miss the chance to have humidity control. We keep ours at 50% and 78 degrees in the summer and you can get chill bumps. Especially when it is 95 and 90% humidity outside. It is solid state boards, but not one service call yet.
Your price doesn't seem out of line.

 

[CNGsaves]

I'm with BrewChief that you at least get 2 stage if you're going to settle for 80% furnace . . . . especially if you go with major brand like Lennox. For Memphis you'll need to go with system that best handles your environment there.

I'd got 15 yr old Lennox Pulse and it's 90% so when mine konks out I'll be looking at 95% or greater.

However, the reply from OKC guy who improved his ductwork at same time as HVAC replacement likely has the best setup. Ductwork when done properly really makes the system work all that much better.

I'd sure look for an A/C system that is better than 14 SEER that seems low as I'd shoot for 16 SEER . . . . but it also depends on how long you plan on staying in house before you invest heavily in HVAC system ; thus, you may be forced to update the lineset.

 

[wesalexleft]

Thanks for the quick link. It gave me a price of 7330.00 for the lowest efficiency and 8470.00 for the mid-range. I think I'll fall at the lower of the midrange, so I guess he's spot on for price. I know when my " guy" came out, the first worry he had were which units would fit through the attic access. This is a two story, and the evap and furnace are in the attic, so really two flights of stairs. The attic access is about 22.5" and we talked about removing springs on the pull-downs to get needed clearance. I think he's being limited to models by that as well. He seemed to know them by heart and mentioned a "C" unit which I assume is a sizing standard. Hopefully I'm good. My old comdenser unit was a 13 SEER, but was not matched to the evap coil, so he estimated i was seeing a true, 10-11 SEER and the new matched 14 SEER should be noticed.

 

[pseudorealityx]

The Lennox variable speed stuff with the dehumidification controls is a really nice setup.

The fan being able to run at lower speeds is a nice energy cost benefit...especially since it's a larger 5 ton unit.

 

[Milton Shaw]

I would recommend replacing the line set. The new unit will be R410a which is a lot higher pressure and use a different family of oil. Any oil left in line set will affect the new system and the older lines may be leak prone under three times the pressure they have been under for 20 years. That would let you go to the higher SEER unit with the larger lines. Do go full size on lines from unit to unit and make sure they don't have sags in them that would trap oil.

 

[wesalexleft]

Got with my guy first thing this morning about the variable speed/humidity control unit and he'd already set me up with the Lennox SL280 with dehumidifier capability. That looks great and thanks for all the input on here. I hadn't really "researched", since it just quit on me, but I'm liking this more and more now that I see whats available 15 years later than the last time I looked at them. I'm going to have to shop for the icomfort thermstat now...
As far as lineset, we talked about it, but this is a 2 story colonial brick and the existing lineset is run within the wall for much of the run in order to get it to the condenser. The guy said he could replace "most" of the lineset with a larger diameter in order to get to the higher SEER, but that it would still have a restriction where its within the walls. The only othe way, would be to have it exposed running down the house, or some MAJOR work, hence sticking with the 14SEER and the existing lineset due to the suction line.
Now over to the "what did you do in your garage today" which for me is going to be last night...slept in the garage. The window unit there is working great and although the rest of the family refused to sleep there, I was good with it on an air mattress. Nice view of the bikes too.

 

[pop pop]

Wes, if the lines are in sheetrock walls, interior access can be done fairly cheaply. Lots of mess with the drywall, but I'd think about it.

 

[Mike007]

I would recommend replacing the line set. The new unit will be R410a which is a lot higher pressure and use a different family of oil. Any oil left in line set will affect the new system and the older lines may be leak prone under three times the pressure they have been under for 20 years. That would let you go to the higher SEER unit with the larger lines. Do go full size on lines from unit to unit and make sure they don't have sags in them that would trap oil.

3X the pressure? Generally the suction pressure will be roughly double and the liquid will be less then 100 psi higher. These pressures will not be a problem as long as there are no soft-soldered joints in the line-set. Ive heard some stories about soft solder joints failing when the system is converted over to 410A.

And if it's a major expense/difficult to replace the line-set and it's brazed, there is no reason not to reuse the existing. Especially if it's mostly vertical. I believe in flushing an existing line-set when changing to 410A, but I do know guys who never flush, have been installing 410A for 10+ years and aren't reporting any issues. They just pull a good proper vacuum and thats it.

 

[acmikee]

change your line set.

reason your old compressor went to ground and has all of that contaminated oil in the lines..... the oils between 22 and 410 are different.

 

[danski0224]

I know this isnt "garage" related, but just wanted to get some cost opinions. Our 15 y/o central AC quit...compressor shorted to ground. It's an R-22 system, 5 ton, in a two story house. I have a "guy" who's always treated me well on repairs, and he's quoted me a new system for $7800.00 which includes a Lennox 14 SEER 5 ton unit, new evap coils, etc, and a new two stage 110K gas furnace. Does this sound about right installed? The house, built in the 70's is set up for one unit only and we both agreed it would be very tough(expensive) to convert it to a two unit AC system. In addition, I have a 7/8" suction line which kind of prohibits the newer high SEER units with over 1" suction lines. the lineset runs from the attic of the two story to outside and currently has a run over over 30' I'd guess. The current furnace it at least 15 y/o as well, so I'm guessing it wouldn't be much longer before I had a cracked heat exchanger, so having the whole thing priced.

Too many variables to comment on pricing.

But, you will NOT get the rated efficiency out of the new equipment if the airflow is not up to snuff.

Proper airflow is also critical for the variable speed motors because those will make every attempt to deliver what they are set for, to the point of self destruction. If the motor doesn't self destruct, your amp draw will be way higher than the plain old PSC motor, negating any energy efficiency gains.

A two hole total static pressure test can determine whether or not the existing total duct + coil + filter is too restrictive or not. Additional test ports can narrow down problem areas.

I assume that your speced equipment has an AHRI match? If not, you won't get the SEER rating, assuming that the airflow is good.

Did the person installing your equipment do a proper load calculation, or did they do an "old equipment label" calculation? 110k BTU in Memphis??? You live in a 3k+ SF house (80% AFUE) with no insulation?

Airflow is determined by the equipment requirements, so some "duct problems" can be reduced by installing properly sized equipment.

Does your current system have one air filter or two? If you have a 5 ton drive and only one air filter, I can guarantee that your airflow is not right and you are most likely getting only 4 tons (or less) of airflow at the equipment, before duct losses- which are very significant in a typical residential attic duct system.

As far as linesets go, there are tables that tell capacity losses for less than ideal installations. Changing them is always the right answer, but sometimes it isn't practical (homeowner doesn't want the mess) to impossible. There are flush kits and suction cleanup driers available.

Proper installation is key. I bet your existing condenser should have had an 1-1/8" lineset. Equipment failures due to poor installation are at a ~10 year to 15 year horizon, depending on just how badly it is installed. Almost anything will hold together long enough to make it through a 1 year warranty.

There are also specific piping practices when the evaporator is located over the condenser (different practices for the opposite situation).

Good luck.

 

[danski0224]

Have no clue what SWAG means

Scientific Wild A$$ Guess

I would recommend replacing the line set. The new unit will be R410a which is a lot higher pressure and use a different family of oil. Any oil left in line set will affect the new system and the older lines may be leak prone under three times the pressure they have been under for 20 years. That would let you go to the higher SEER unit with the larger lines. Do go full size on lines from unit to unit and make sure they don't have sags in them that would trap oil.

Any properly performed copper braze or solder joint has a tensile strength exceeding 410A operating pressures. Of course, the key words are "properly performed".

 

[mister_two]

Took a day off from work yesterday and had about 6 HVAC companies come out to get quotes on a central AC system.

It's a one bedroom condo in NJ with about 1100 sq feet. Two story condos, my unit is upstairs. The condo is about 30 years old, the current central AC is an original Bryant unit about 2 ton, R-22. I didn't know they still make R22 condensers. The heat furnace work fine so I just needed the condenser and the coil. The CHEAPEST way to go would have been to just replace it with another R22 condenser. But decided to upgrade to R410a with a new condenser and coil. Prices vary greatly HD and Costco quoted me the same Lennox 2 ton. HD price was 4k while Costco was 4400. HD also had a 24 month free financing. Another quote was 3600. One company quoted me a Carrier 2 ton with new coil, disconnect, flush the line, new pad for the condenser for 2500. I went with this deal.

Shop around.

 

[DoyleDee]

You can still get R22 condensers, they just come withought refrigerant. If it were me, I'd buy a new R22 unit and just replace that (the condenser only)- no new lineset needed and lower pressure. I'm not on board with 410a units..... higher pressures mean what?? easier to leak, and because it is a blended refrigerant-after a certain percentage is lost (leaks), most want to purge and refill for the correct blend.

Do what you wish, but for me this is what I would do. (R22 is no longer going to be produced.... or is it?? - what happened to R12?? and then they came out with "Freeze 12".
I'm just not buying it. In this economy, times can be hard..and money in my pocket makes me feel better about my own standing.

 

[danski0224]

You can still get R22 condensers, they just come withought refrigerant. If it were me, I'd buy a new R22 unit and just replace that (the condenser only)- no new lineset needed and lower pressure. I'm not on board with 410a units..... higher pressures mean what?? easier to leak, and because it is a blended refrigerant-after a certain percentage is lost (leaks), most want to purge and refill for the correct blend.

Do what you wish, but for me this is what I would do. (R22 is no longer going to be produced.... or is it?? - what happened to R12?? and then they came out with "Freeze 12".
I'm just not buying it. In this economy, times can be hard..and money in my pocket makes me feel better about my own standing.

So much misinformation.

Higher operating pressures do not create leaks.

R410-A is an azeotrope. Look it up.

A "new" R22 condenser is "13 SEER" and your old coil is not, resulting in a mismatched system.

Those "dry" units are exploiting a loophole and are classified as service replacement parts . You can't buy new R22 evaporator coils unless you find a NOS one or convert a 410 coil.

Major repairs to a residential 22 system is throwing good money after bad.

 

[edac]

I would go high efficiency on both units as they save on operating costs. that means a high efficiency air cleaner, to keep the new equipment clean. Now would be the time to consider splitting the system and installing two, redundancy is nice and makes future replacements more reasonable. Check with more local contractors.