On 3 Mar 2006 03:59:54 -0800, "katrina"
wrote:

At least 4 times wihin the past of couple of years, i had called A/C
maintenance people to take a look at my a/c unit for not giving cool
air. They all found freon level was too low. Filled the freon,
tightened the valve here and there. But few weeks later, the same
problem again. One a/c guy said coil was leaking and gave me an
estimate of $3000 to replace it. i called other a/c guy for his
opinion. He said there was nothing wrong with coil system. Coil is in
my attic. i did notice, attic gets cool when i run the a/c although
there is no a/c vent in attic. then i found out there was cold blow of
air coming from joints around the coil system box. is it normal to get
cool air blowing out from coil system? I taped all those joint
openings. i also hear some hoarse/dry noise coming out of the coil in
the attic that i do not hear from another coil system in the first
floor (we have two a/c system, one for each floor). Eveytime a/c guys
show up they fill up the freon, clean the shrubs around compressor,
tightens the valves, but the problem does not go away. i wanted to put
this problem here before calling a/c guy for the fifth time. what
should i ask him? why they can not fix the leak which is the obvious
problem? How do i find out the leak and fix it?


Yes, plenum leaks tend to occur over time as do leaks in the duct
distribution system. Go through the whole thing and check and tape
all. When you do be sure to not compress or remove the insulation or
you will potentially get condensation that will leak onto your ceiling
and stain or ruin it (assuming you have attic duct work).

Depending on the size of the unit $3000 is a little strong for
replacing the evap coil. If it is an old unit you might want to
replace the whole thing with a high efficiency unit, take the tax
credit and let the energy savings pay for the balance. I just
replaced a whole 5 ton packaged heat pump for $3900.

At the very least, get a second opinion from some one else if your AC
guy is not getting the job done.

Frank