Rheem 5 ton a/c condenser - small pin hole leak

[richard8]

Hello,

I have a Rheem 5 ton residential a/c condenser unit that sits outside the house.
This unit and all the similar ones in this neighborhood are approximately 19-20 years old.
This type of a/c condenser uses standard R-22 type freon.

I had this unit charged up with approximately six pounds of R-22 freon. This was done in July 2009. When rheem 5 ton was checked in the past three weeks (early May 2012). The Rheem 5 ton condenser was empty..

It did not need to have any freon added in 2010, nor 2011. This unit is usually used between May 15 - September 30.

Does anyone know of solutions to solve this problem.

What do you recommend or do not recommend.


Thanks for any advice.

[jimbo]

If the condenser is "empty" I would suspect a pinhole coil leak, but it still could just be a fitting on the charging ports, etc. An electronic leak detector would help narrow that down.

A 5 ton unit will take 6 to 8 pounds of R22. To the contractor, R22 is about $16 to $20 per pound. To the customer, that might be $25 to $50 per pound. Do you really want to put $400 worth of R22 in a 20 year old unit?? BY LAW, you can not just add refrigerant...you must determine the source of the leak. Can you say EPA and $25,000 fine in the same breath!!!!!!

Now, given the age, it is quite likely that you can not make a 13 SEER dry 22 unit work on your old, 10 seer or less, evaporator. For sure, you could not make an R410 condensing unit work. SO, you are looking at a new system as the proper course of action.

[richard8]

If the condenser is "empty" I would suspect a pinhole coil leak, but it still could just be a fitting on the charging ports, etc. An electronic leak detector would help narrow that down.

A 5 ton unit will take 6 to 8 pounds of R22. To the contractor, R22 is about $16 to $20 per pound. To the customer, that might be $25 to $50 per pound. Do you really want to put $400 worth of R22 in a 20 year old unit?? BY LAW, you can not just add refrigerant...you must determine the source of the leak. Can you say EPA and $25,000 fine in the same breath!!!!!!

Now, given the age, it is quite likely that you can not make a 13 SEER dry 22 unit work on your old, 10 seer or less, evaporator. For sure, you could not make an R410 condensing unit work. SO, you are looking at a new system as the proper course of action.

Thanks,

Is the information you mentioned valid for California state laws. What if the small .0001 " inch or less diameter hole is behind the stucco wall. Not in the condenser, or outside the house.
You are correct about R-22 pricing, it is usually tripled by the time it gets to the residential customer, and maybe 65 bucks by July 20 - Aug 29, since it is over 98 degrees outside..

It was mentioned to me since the leak takes 28-32 months, i.e. slow leak, it would be okay to just add freon R-22 and use. This is not me adding, since I am not licensed, not EPA certified, and illegal to purchase
the R-22 freon. This is information from licensed contractors.

What about stop leak alternatives, different solutions.

If that is not available.

How much is going price for R410 5 ton 13 seer, Good name brand, with decent warranty.
Do they need to install new evaporator coils, what about the copper line, is that all brand new too.


Thanks.

[Runs with bison]

In the past there was a given leak rate that determined when replacement was required. I want to say it was something like 1/2 charge per year or more. Yours is probably below that level unless the leak has increased greatly in the past year.

Makes sense to identify the source of the leak if you can. Some things can be replaced cheaply enough.

My neighbor's AC seems to have a rather high leak rate...if it leaks down enough again this summer I'm hoping it will be condemned, it's a noisy old thing and any replacement will be quieter.

EDIT: I should add that there is a good chance your 5 ton is oversized by a large margin, but that would take some investigation to determine.

[jimbo]

If it has gone empty just since September, that is not a small leak! California laws do not apply...this is EPA regs.
I would still make the point that since you will be paying quite a bit of labor for trouble shooting and repairs...do you want to come out of that process with a 20 year old unit? By next year, R22 will cost more than gold bars!

Bison makes a good point about size.....how many square feet are you cooling with this?

It does all boil down to $$$$. A reputable contractor will give you a some cost comparisons. Now is the time to act quickly. If you wait to the peak of the cooling season..it becomes harder to get good work a reasonable price.

[Runs with bison]

If it has gone empty just since September, that is not a small leak!

Unless it actually had a verifiable full charge in Sept. (which I doubt) and is truly "empty" now, which I also doubt, the leak has instead happened over three years dating back to the last charge in 2009. I had a unit back in Texas that leaked enough that it had to be topped off at least every other year. The wt. charged will give some indication. My neighbor's unit now is leaking at what appears to be a similar rate requiring top offs every other year or so.

Anything other than a simple evap coil, valve, or tubing replacement is going to get too expensive to justify on a 20 year old unit, especially since more than likely the compressor will fail within a few years and the whole thing will have to be done anyway. I'm not even sure if the evap. coils can be replaced anymore (HVAC folks will know.) It's also a crapshoot as to whether a given repair would for certain end the leak down...

Not sure what SEER level the old unit is, probably no more than 10 actual even if it is stamped higher. Replacing a SEER 10 with a nominal SEER 16-18 unit gave me a measured reduction of over a third in cooling costs--this is adjusted for temperature and baseline electric use over the course of a summer. It won't pay for anything quickly, but with our electricity costs the difference is about $150-200/yr. Couple that with no more maintenance cost for several years.

At any rate, when replacement is considered, the heating side will also have to be analyzed as well. With furnaces the AC size typically determines the air handler frame size.

[richard8]

Unless it actually had a verifiable full charge in Sept. (which I doubt) and is truly "empty" now, which I also doubt, the leak has instead happened over three years dating back to the last charge in 2009. I had a unit back in Texas that leaked enough that it had to be topped off at least every other year. The wt. charged will give some indication. My neighbor's unit now is leaking at what appears to be a similar rate requiring top offs every other year or so.

Anything other than a simple evap coil, valve, or tubing replacement is going to get too expensive to justify on a 20 year old unit, especially since more than likely the compressor will fail within a few years and the whole thing will have to be done anyway. I'm not even sure if the evap. coils can be replaced anymore (HVAC folks will know.) It's also a crapshoot as to whether a given repair would for certain end the leak down...

Not sure what SEER level the old unit is, probably no more than 10 actual even if it is stamped higher. Replacing a SEER 10 with a nominal SEER 16-18 unit gave me a measured reduction of over a third in cooling costs--this is adjusted for temperature and baseline electric use over the course of a summer. It won't pay for anything quickly, but with our electricity costs the difference is about $150-200/yr. Couple that with no more maintenance cost for several years.

At any rate, when replacement is considered, the heating side will also have to be analyzed as well. With furnaces the AC size typically determines the air handler frame size.

Thanks,

The furnace portion is an 11 year old Lennox, 100k BTU, in the attic of a two story house.
The condenser, is a Rheem 19-20 year old 5 ton unit. Installed for all the houses in this neighborhood in
1992-1993.

The furnace was replaced under warranty due to fire damage lawsuit 11 years ago.


If I choose to replace condenser, do I need to replace evaporative coils also.
What about the copper tubing, and other lines.

Does the evaporative coils and sheet metal need to replaced if upgrading
to R-410 type freon,

Does anyone know if Goodman, Payne are good manufactures. What about pricing,
warranty.

[jimbo]

If I choose to replace condenser, do I need to replace evaporative coils also.
What about the copper tubing, and other lines.

Does the evaporative coils and sheet metal need to replaced if upgrading
to R-410 type freon,

Does anyone know if Goodman, Payne are good manufactures. What about pricing,
warranty.

If your evap coil is 20 years old, you probably need to replace it regardless. If it is just 10 years old, you could make a new 13 SEER 22 condenser work. If you switch to R410, it may still be possible. They will want to replace an indoor piston with a TXV, and of course the coil and lines will need to be flushed. All of that adds $$$$$$$

Goodman is a good solid brand. Payne is the economy brand of Carrier, and has made some quality strides this year.

[Dana]

I'm still trying to wrap my head around the notion that any mid-sized home in WA that that actually HAS a 5 ton cooling load. The crusty old school "lessee, 2500' divided by 500 foot-a-ton comes ta..." oversizes things even for barely insulated homes in Florida with ducts in the attic flying uninsulated above the flimsy R11 batts in the attic.

With ducts inside of conditioned space, reasonable R values, and double-paned window (preferably low-E, at least on the west side, if unshaded) 1000'/ton is going to be a better rule of thumb, even for FL. In WA the latent loads are a fraction of the southeastern US, and the 1% outside design temps lower too. And if "Washington"== Washington D.C., even 2.5 tons would usually be enough at current code-min if the ducts aren't in the attic. Before specifying a replacement, run Manual-J heating & cooling load calc using realistic design temps and building parameters. Don't put your thumb on the scale with 68F inteirior temp or using outside design temps 5-10F above the ACCA/ASHRAE published 1% data. Most homes (even in the hot'n'dusty Columbia Basin towns, if WA) won't need more than 2 tons cooling, and right-sizing it will be more comfortable, less expensive up front, and it's easier on the equipment by letting it run longer & fewer cycles.

Old habits die hard, expect push-back from the HVAC companies, but even if you have to pay a home-energy nerd $500 to run a legit Manual-J for you, it'll save that much on the equipment (or more), and you'll be more comfortable in the end.

When the ridiculous 6-ton York that came with my house dies it'll be replaced with a 1.5-2 ton ductless, provided I live that long. The thing barely runs 20 hours/year in a hot year, and since most of my load is latent the dehumidifier in the basement uses more annual power. But maybe with climate change it'll see a higher annual duty cycle soon. :-) Since a ductless will modulate output down to a fairly low output, it'll be more likely to work out for me having it cycle on at minimum speed for a few hours on most warmer days, yet still keep up when it's in the 90s. A 2-ton bang/bang controlled unit wouldn't work nearly as well, but even that would be a huge improvement on the oversized status-quo.

[Runs with bison]

Forgive my lack of experience on this, but I'm not sure how replacing just the condenser is feasible, do they do that or just slap in a new condenser and compressor outside? I can't see this being cost effecting with an old compressor.

One of the things to keep in mind when considering doing this piecemeal is the manufacturer warranties. The warranties I've read have indicated that unless the whole system was replaced with their matched kit (outdoor unit, plus indoor coil and air handler), then they wouldn't be responsible for major components of the warranty. That was kind of an overriding factor for me when looking at major components with 5/10/lifetime warranties.

The SEER 13 unit might very well be SEER 10 with no TXV...that's what my 1994/1995 unit was. That came up when I was considering an evap coil replacement soon after moving in--this was due to the high airflow DP I was seeing across the inexplicably narrow coil. (Turned out the evap coil was some sort of aftermarket job, probably installed as part of scale up of capacity of the unit in the first year because it was undersized for the poor distribution/insulation they had at the time. Figured that out because the outside unit was a year newer than the home build/mortgage/occupancy.)

Have some actual calcs done for the home. 5 tons sounds awfully big.

Another thing to ask before believing or disbelieving a capacity quote is this: When the unit is properly charged and running well, and the weather is near its hottest, does the unit run continuously and barely hold set point? (And for AC I consider a reasonable set point to be something like 78-79 F...others might prefer cooler temps.) If you find that instead it is only running 1/2 - 2/3 of the time in late afternoon on a very hot day then it is way oversized.

[jimbo]

Bison...I think we are all in agreement about needing to confirm the sizing. On the other hand, many customers expect to be able to come home at 4 in the afternoon when the system has been off all day and the house is 100....they want to be able to blast that sucker on high to cool off!!!!!!!!!!

[Dana]

Another thing to ask before believing or disbelieving a capacity quote is this: When the unit is properly charged and running well, and the weather is near its hottest, does the unit run continuously and barely hold set point? (And for AC I consider a reasonable set point to be something like 78-79 F...others might prefer cooler temps.) If you find that instead it is only running 1/2 - 2/3 of the time in late afternoon on a very hot day then it is way oversized.

On the ridiculously oversized system at my house it only runs one cycle/day, usually for less than an hour. Due to southwest shading factors, by the time it trips the setpoint the entire house is already in shade, or soon will be. The fact that it doesn't run longer makes for poor latent-load control, but it does dry it out in the brief period it's running.

jimbo: Even if the unit is right-sized as opposed to 3-4x oversized, if the house is 100F when the client comes home the temperature and humidity still drop rapidly at least in to the mid-80s. In a newer-tighter homes with low-E glazing (or no west-windows) the peak cooling loads are a fraction of what previous rules of thumb were indicating. The nice thing about a ductless AC is that the turndown ratio between max/min output is huge, and you can get away with oversizing for a more rapid cool-down without taking a hit in average-load comfort & efficiency- the part-load efficiency is quite a bit better than at full blast. But even 50% oversizing would allow rapid cool down without the short-cycling at part load that comes with ridiculous oversizing factors.

[richard8]

Hello,

What is the approximate cost of a 5 ton 13 seer, R410A unit condensor costs.

What is costs with thermal expansion valve, new copper tubing, and evaporative coils.

If the leak, i.e. pin hole is .0001 or smaller, and it takes 30 months to go to empty.

Is stop leaks an alternative.

[jimbo]

A Goodman unit, middle of the road, will run your contractor $1450 or so. He will need to nick you $2400 I suppose.