wrote:

I've been reading deja articles for hours on separate days - but I
would like some quick advice if possible. I'll try to keep the story
short.

Moved into a condo; very old Lennox upflow heating/2-ton air
conditioning unit. 900 sq ft open space (no bedrooms/doors)

The air that comes out of the registers is _somewhat_ cold - but not
cold as I like it to be. As a result, I can only maintain the indoors
temperature at about 78, no lower. I would like to get down to 70 if
possible (outside temp 80-95).

It appears that the previous owner did not have an air filter where the
air got sucked in by the fan... so I put in a new filter. Due to the
way the unit is positioned (basically inside a closet) - I'm not sure
if having a filter is causing a problem by possibly restricting intake
of air.


How much space is below the furnace closet floor?
Lack of Return Air Grille Area could very well be restricting the
airflow to & through the cooling coil!

Check thoroughly for hot air leaks from the attic down through the wall
petitions to under the air handler!
These are common problems I have found over the years of servicing A/C
systems.
If you have room put large return air filter grilles along the sides
under the furnace closet floor, do so.
This will allow you to have more open air return area for the lint
loading of filters. (See Linked page.)
If you can use the other return filter grilles, if airflow is then not
adequate, remove the furnace filter.


There is no icing on the pipes at the outside condenser unit as I can
see. The alum fins on the condenser unit looks ok, free of debris. I
had a guy come out and fill it with a pound of R22, he said it was low.
I did notice some improvement, I can go down to about 76 now, but
still I would like to go down further to 70. Am I asking the unit too
much?

What else can I check to narrow down the issue. From reading some
posts, how do I check evap coils (this coil is different than the
condenser right?) & condensor/coil water drain (not sure where this is
located)?

I realize that the AC guy is supposed to be doing this stuff for me,
but to make a long story short I do not get to choose who comes by to
diagnose the unit. In the event I do have to shell out money, I would
like to be informed. Thanks for any suggestions


Well, if your "Design Conditions" are similar to mine": 88-dry bulb,
73-wet bulb , around 49% Relative Humidity, then "a mere half ton
6,000-Btu/hr" window shaker with a floor fan setup like mine would get
you to 76-F and to 50% RH even on high humidity days. Your unit is
2-tons or 24,000-Btu/hr, 4 times the capacity of mine!
http://www.udarrell.com/aircondition...harting.h tml


What do you want to bet that your 2-tonner is not getting anywhere near
2-tons of heat transfer from the indoor air to the outdoors!
Also, it must not be reducing the humidity sufficiently or you would
feel very comfortable at 76-F.

My 6,000-Btu/hr Whirlpool remote control room A/C only cost around
$130.00 and cools well within the comfort zone around 920 sq. ft. on the
hottest days imaginable, 112 Heat Index days! Am I a happy camper, you
bet I am!

With the power disconnected check the blower wheel blades; if they are
filled with lint then the evaporator coil is plugged and insulated too.
No system should be charged with refrigerant until it is confirmed that
the evaporator has an optimal heatload being absorbed by it!

The condenser may appear to be clean to you, but could be blocked
between the fins and/or the fins cold be insulated by wrong cleaning
methods such as using oil based detergents when it was cleaned in the
past. (It is very old!) Both coils should be thoroughly cleaned with a
good coil cleaner; the evaporator should be thoroughly cleaned with a
good evaporator cleaner.

Only then, should the system charge be balanced:
http://www.udarrell.com/ac-trouble-s...ubcooling.html

Leave all, these jobs to a good tech! - udarrell

--
Factors in the Correct Sizing of Residential Air Conditioning Systems -
Recommended Procedures for Proper Duct Sizing of Residential Air Conditioning Systems
http://www.udarrell.com/proper_cfm_b...syste ms.html