House AC Issues..?

Sep 16, 2005 24 Replies

Hi Folks..



I'm having an issue with one of the AC systems in my house.. For some reasons only the upstairs unit seems to be leaking freeon.. But I've had a tech come over, and check for leaks, using a device amde by Infinicon-Tekmate, that emits a beeping sound when freeon is detected.. However, the tech wasn't able to detect any leaks using that.. Then he tried using the bubble detector solution, but wasn't able to find any leaks with that either.. He did this in both places, in the attic near the coil, and outside by opening the unit near the compressor..



He said that the only other place that the freeon could be leaking is in the pipes from the upstairs unit to outside, which would involve drilling a hole in the wall, pulling the pipe out, and replacing, and then repairing the whole in the wall..



However, when the tech replaces the freeon (with upto 2 pounds of freeon), the AC is ice cold again, and the last time he recharged it, it lasted for 2 weeks. Hopefully this time it will last longer, and the summer in the SouthEast will be over..



I've also replaced the filters and vacuumed the vents..



Has anyone seen this before.. where the freeon leaks over a period of say 2 weeks, but can't be detected, and upon recharging, it works fine.. for another 2 weeks. ?



Thanks in advance for your help..


That's a pretty well written description. IFF the tech was reliable, then you have a leak in the walls, it seems funny he wasn't able to detect it anywhere. If it's leaking into the walls, there has to be an exit point for it and it'll be detectable there.

If it's actually "freon" as you said, that has a pretty good odor and at the loss rate you indicate, you should be able to smell it yoruself, even.

How does he/you know, if the detector was functioning and being used, correctly?

Also, if this is in the attic, I don't know why a hole would have to be made in a wall. It should be pretty easy to pull out the old and fish in a new pipe. IMO at least; no expert here, just an avid diy'er.

Just my two cents; I know it isn't my money, but if I were you I think I'd try another service and if they came up with the same results, consider replacing what needs to be done. It's still cheaper than paying housecalls for freon every two weeks in your climate.

Thanks Dr.. !!

Now is the UV dye injected into the freeon systems, and if not, how exactly is it done..

Thanks

Dr. Hardcrab wrote:

Thanks..

Well.. the tech is working for a company that is certified. and so on.. But as to his reliability, I guess only time will tell.. unfortunately..

I didn't know that freeon had an odor.. I thought it was one of those odorless gases..

Regarding whether the detector was working properly, the tech did complain about the batteries, and so I replaced them with 2 new ones of my one, that I just bought the day before, and it still have the same results..

Thanks

P> That's a pretty well written description. IFF the tech was

Thanks..

Well, it looks like I will be trying another service..

Is the description below referring to the specs of a Tek-Mate ?

Features: >

Thanks

Travis Jordan wrote:

This is Turtle.

If the Tek-Mate operating correctly, is operated correctly, and operator knows how to read the results. If it does not show a leak , there is no leak in your hvac system. so if your system does have a leak that let's it run out of freon in 2 weeks --- you need another Tek-Mate or a new operator.

..4 oz./yr sensitivity of the Tek-mate, i could be wrong but i was told it was like 1/8 oz. per year leak it will pick up.

TURTLE

If it's losing the charge that quick, then you need to call another company to find it and repair it. There are other ways other than using those electrocnic "sniffers". Many of those give false (or no!) readings. I've had better luck with ultraviolet dye.....

Not to nitpick, but

"Pop" wrote

Smell? Orderless and tasteless. Add a flame to it and you will get a smell. (O.K., and it DOES taste cold....;-] ). If it's leaking that fast, you may even HEAR it....

I'd like to see you "fish" a 3/8 and an insulated 3/4 inch copper tube up 2 stories through several inch-and-a-half holes. Not an easy task. In fact it's damn near impossible. ESPECIALLY if the original installed strapped the lines to any of the studs in the wall.....

How right you are.....

Either the Tek-Mate is broken, or it was turned off. With your leak rate it should have been beeping anywhere in the vicinity of the leak!

Features:

a.. 0.4 oz./yr. sensitivity to CFCs, HCFCs, and HFCs

It's my understanding that freon (like methane or propane) is odorless. In the real world, we use odorizing chemicals so we can smell them (mixed in with the natural gas or propane).

In the case of "smelling freon" that would be the lubricating oil you smell.

Yes, it's very possible. there are a bunch of places freon could leak, and not be easy to detect. It's very possible there is a leak in the lineset. However, as the other fellow wrote, you'd think he could have detected the leak where the tubes go in and out of the wall.

I'd also suggest to call a second service company. Ask them to come over and find the leak for you.

Your description "add two pounds and it's cold as ice for two weeks" is classic description of freon leak.

Yes. His Tek-Mate's sensor was probably bad.

The most common places for leaks in a system are the service valves at the condenser (make sure the caps with o-rings are installed over the schrader valves), the lineset (specifically, any brazed joints including

90 degree couplings, if such were used), then the evaporator coil. I'd really be surprised if there was a leak in the lineset inside a wall, although this sometimes happens when nails are hammered through wallboard into the lineset.

Hung any new pictures recently?

Your understanding is mistaken.

R-12, R-22, and R-134a all have a distinct solvent or medicinal type odor.

It isn't strong enough for practical leak detection, however.

Your leak is fast enough that a leak detector should easily find it. Yet yours doesn't. So I'd look at the evaporator, which is the easiest place to miss such a detection.

DuPont and I would describe the odor as 'slight ethereal, but most people can't smell it in concentrations below about 20%.

formatting link
Physical Data

Boiling Point : -40.8 C (-41.4 F)

Vapor Pressure : 151 psig @ 25 C (77 F)

Vapor Density : 3.03 (Air=1.0) @ 25 C (77 F)

% Volatiles : 100 WT%

Evaporation Rate : >1 (CCl4=1.0)

Solubility in Water : 0.3 WT% @ 25 C (77 F)

pH : Neutral

Odor : Slight ethereal

Form : Liquified Gas.

Color : Clear, Colorless.

Liquid Density : 1.194 g/cm3 @ 25 C (77 F)

Yeah.. That's probably what it was..

Since I did replace his batteries with new ones that I just bought, his sensor on his device was probably bad..

Thanks

Travis Jordan wrote:

Actually, I did, not recently, but about 2 and a half months ago (around the end of June, or at the very latest, the 1st week of July) And the first AC issues I started noticing were in the last week of August, and that's when I had the freeon replaced..

It was only one nail though, and not a big one, just for a cloth painting hanging on light cylinder shaped piece of wood..

Hope that's no it.. If it is, can I just remove the wall hanging, the nail, and then maybe the replace the freeon, and see if it leaks out even faster, since the nail isn't even there to stop it..

The odd thing is that, I put the nail in say in the 1st week of July, and the freeon supposedly leaked out in the end of August. But everytime I've had it replaced, it leaks out in about 11 to 11 days..

Does that then make sense.. ?

Thanks

Sam

Travis Jordan wrote:

Thanks..

Where is the evaporator ? Would be upstairs in the attic near the coil, or outside the house, where the line comes out, in the compressor unit / AC unit ?

Thanks

Richard J K> user writes:

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