Suggestions for better cooling

[aw]

Called a large local on-time service company because the unit was only getting a 14 degreee split and generally not cooling the house below 79. He took some readings at the condenser and said your pressure it too high..around 300 or so. He cuts off the old line dryer, blows out the piston, installs a new dryer and re-charges. Everything is the same as far as I can tell. Nothing has changed performance wise.

System:

3 Ton 1994 Resco condenser with a 2003 Carrier air handler/heater in the attic.

He did not write any of the pressures/voltages etc on the paper work.

Any suggestions for the next guy?
I know a 10 year old condenser is in its twilight, but is there anything that can be done to squeeze out a better temp split?

[Edmund Forsthe]

gee i would of tried cleaning condenser first. maybe a bit overcharge did it work after he got done. what type of metering device

[dec]

Originally posted by aw
. He cuts off the old line dryer, blows out the piston, installs a new dryer and re-charges. Everything is the same as far as I can tell. Nothing has changed performance wise.


Now thats what I call a true go and blow.......

[Irascible]

Looking at your previous posts I see that Mark suggested a coil cleaning. Did that happen? I'm talking about using foaming agents that are so strong they'll burn your skin. Use that stuff properly and you'll have one clean coil. You'd be amazed at how often a coil can look clean on the outside and have tons of junk packed in the fins.

A ten year old unit could be on its last legs. But it could last another 20 years. Don't let the propagandists convince you that 10 is automatically ancient.

It sounds like you need to find a good contractor. My sympathies. I routinely say that 80% of contractors are either incompetent, crooked or both. I'm known around these parts as an optimist.

[aw]

The coil was cleaned by the tech...I believe with the garden hose.

The metering device is not a TXV...it is inside the sheet metal cabinet.

Coils look clean on the outside like you said. Did the sheet of paper test as mentioned and it sucks to the coil.

As far as a ten year old unit being on its last legs, is it possible to keep rebuilding? I know at some point parts and labor will pay for a new unit as well as increased efficientcy.

I think the contractor that worked on my unit was too incompetent to know what being crooked is.

[Irascible]

A garden hose alone is worthless without a special cleaner in some cases.

Replacing instead of fixing over and over is a valid thing to do. But I find that quite often the machine doesn't really need to be fixed over and over. It needs to be fixed once correctly. If you've had bad luck in that regard then I understand the desire for a new unit. But what if the problem doesn't have anything to do with the outside unit? You'd end up having to replace the whole system just to make sure you covered all your bases. You're better off with a good tech that can diagnose the real problem. Once you get that then repairing can once again be an attractive option, or not depending on what the good tech recommends.

[tinknocker service tech]

it is possible someone is trying to overcome something. maybe a restiction in the system or dirty coils or lack of air flo. when he had the system down did he check the screen by the orfice or just try to blow it out. most of the time blowing it out does not work the screen should be removed and cleaned then put back in

[aw]

Looked into this a little more last night around 11:00 pm when the outside temp here is around 80-85.

Got the split I want during the day...17.7.

So from night to day it goes from 17.7-14.

[docholiday]

You know, this is a mismatched system and who knows if the piston in the carrier coil is the right one for the outdoor unit installed?

There are other issues that need to be addressed. In fact, all we have a temperature differences, maybe, the return duct is in the attic and sucking hot air. In the evening, the attic air is cooler and is not having the same effect.

In the evening the pressure is lower and therfore the coil is cooler.

You also would need to know the airflow. If it is high you may not see the temperatre drop you want. If the RH is high, you may see a low temperature drop. If the unit is unsersized the latent load is cutting into the sensible load of the coil.

If on the other hand, this system worked before but not this year, then I would check the coils and clean them, and also inspect the ductwork.