[dfphoto]

Hi group, I bought a condo 3 years ago sad to say been in construction hell the entire time. Very stupid of me, beyond that I have an AC issue, two years ago there was no AC I feared the worst and had the AC guy come out and he said needed 1-2lb of freon. After that all was good, but two years of construction issues and sanding drywall for months, I had a duct guy come to vacuum. He turns the AC on and nothing but a fan... we go up on the roof and notice A. all my insulation is rotted to hell, B. the refrigerant line (copper is all green, and some of the worst soldering I've seen. C. I see about 1/2"-3/4" line from the compressor for 3 inches then a crap solder down to a smaller size for 6" and then back to the 1/2"-3/4" (sorry forgot the size at the top of my mind.

I see the run from my compressor location across the roof to a mass exit down the condo roof I am wondering if people generally replace this line, and if I should either replace the weird short piece or is that a normal install. ( I doubt that).

Finally, I grew up by the beach and never had AC before so is a freon recharge a normal situation or could there be a leak. We noticed the pipe started sweating and within minutes froze (the duct guy called the AC guy and his comment was either low freon or too much freon.

The duct guy pointed out the crappy solder job and thought there could be a pin hole leak at one point in the solder job that did look like a weak point.

I'll have photos tomorrow. but would like your thoughts.

Thanks David

 

[roughneck]

Refrigerant is not a consumable substance, the refrigeration circuit is a sealed system. If it's low then it was either not charged properly from the start or it has a leak. Freezing up or running with an incorrect charge can damage or destroy the system.
"Green" copper is somewhat normal outside, especially near the coast. It's just oxidation. The suction line should be insulated to prevent sweating.
Improperly sized linesets can cause turbulence or velocity issues within the pipe, which can cause system damage.

 

[supers05]

I echo roughneck above. If the 6" piece is only 1 size smaller, it'll be fine though. 6" is not really enough to cause a significant pressure drop. (It will cause turbulence, but there's enough pipe inside the unit to compensate for that.)

If you had called me out to look at that, I'd only fix the piping if there's a leak and I'm welding anyways. (especially if it was that spot)

The insulation can be bought at homedepot and like stores. (you'll probably only find plumbing sizes, which will be slightly too big, but tape and insulation glue fix that)

Again, don't run that system until you have had it checked out.

Cheers!

 

[DOUG1111]

Check your E-vap coil- might be packed with drywall dust??? Dirty E-vap coil may fool someone thinking low on refrigerant.

 

[user_12345a]

^To add to that, you have to insist on a superheat test - ideally subcooling too.

Tells the tech exactly what's going on in the system; low airflow and a lot of other problems can cause low pressure even when there's no leak.

Low pressure just means low pressure. Adding enough refrigerant can stop the freezing but doesn't fix the problem - in fact it can cause compressor failure when combined with low airflow.

Your "duct guy" obviously doesn't know refrigeration theory and u shouldn't take his advise; too much gas will never cause freezing. I think lots of professionals in every field aren't thorough -> educate yourself or be burned, incompetence is everywhere.

 

[beenthere]

Has the indoor unit ever been ran while you were there sanding drywall. If so, the indoor coil could also be plugged with drywall dust. Beside the system also being low on charge from a leak somewhere.

The section of copper that is smaller. May be from when some one removed a filter drier, and used the smaller copper to make a coupling section to replace the filter drier.