[pcumming]

Why HVAC people want to replace unit and not coil?

I have 2 10 seer outside condensor units. One 2 ton coil, one 2.5 ton coil. 2-50k BTU gas furnaces. Comfortmaker. Gas Furnace and blower sit on bottom, above that is evap coil, and above that is the plenum if I have my terminology correct. Not cooling like it should for past few years. Been topping off the R22 in both units and that has helped quite a bit. Some summers have to top it off 2x.

Units (attic and they stand vertical) are 12 years old. Had 2 people come out. One person sniffed and said leak is outside at compressor. Other person said leak is in coil. Well they both could be right, wrong, or partially right.

I think the best bet might be to put UV dye in the systems and look at it with UV light and determine exactly where the leak(s) are.
***Comments?

In talking to a few neighbors (same issues) and the 2 HVAC people that came to my house, it appears the HVAC guys want to put in 2 new units including boxed evap coil, new furnace (2) with blower and I assume new higher seer compressor/condensers outside.

Their thinking is that with a 12 year old unit, something else is apt to go wrong soon, so might as well spend the money and replace everything.

Well I think there would be a pretty decent differential in cost between replacing 2 coils VERSUS 2 entirely new units.

**What should a coil replacement cost with labor?

Thanks
PC
Charlotte, NC

 

[beenthere]

The cost varies with the area, and how easy it is to do.

Dye is not a good thing to put into a refrigeration system. I know, it says its made for it. But its not harmless like they tell you.

A tech with some skill can locate the leaks with a sniffer and pin point it with soap.

 

[Marty1Mc]

The cost varies with the area, and how easy it is to do.

Dye is not a good thing to put into a refrigeration system. I know, it says its made for it. But its not harmless like they tell you.

A tech with some skill can locate the leaks with a sniffer and pin point it with soap.

Interesting statement. I would like to know more about that. I have used dye in automotive applications for years without issues. I have trusted it much more than the sniffers I have and I have a few very expensive ones.

 

[beenthere]

Dye's mix with the oil and travel with it. Thats what they are suppose to do, and they do quiet well at it. They also change the viscosity of the oil, and tend to absorb moisture. So it can reduce the ability for the oil to mix with the refrigerant. And moisture in a refrigeration system is a bad theng. And in a system where the motor in in the compressor, it helps to eventually produce acid, because of the higher moisture content.

Automotive doesn't have the acid problem. Since they belt drive.

 

[Doc Holliday]

I came across a system that had dye in it once. The refrigerant was green and thick. It took all night to clean out the line set and the piston and I was originally just there for a condenser change out.