central air cool not cold

[4uzindian]

i have a residensual home with a new arcoaire unit out side. the unit in the attic is from 1998 .the out door unit has checked two times and is charged . the air coming out the vents is about 68 70 degreces. the tech said he'd like to see it at 59 or 60 .could it be bad or dirty ev coils or could the coils be bad.

[niobrara]

Filter clean, coils clean evap and condenser,Air conditioning is the removal of heat. Now model number please.  Is this a 410 a unit with a 22 coil ?

[jumptrout51]

Possible causes ;
dirty evaporator coils
dirty/clogged blower wheel blades
fan motor running too slow
air handler not sealed and sucking in hot attic air
electric heat strip malfunction causing heater to be energized
insulation missing from refrigerant low side tubing

[JWWebster]

If all of what Jumpy said is fine then the A-coil might need to be adjusted.

If superheat is high and sub-cooling is high:
Could have blockage in coil, orifice or line set.

If superheat is low and sub-cooling is low:
Orifice could be too big, there is no orifice in the unit of the orifice is stuck and refrigerant is by-passing it.


Superheat is telling you what is going on in the evaporator.

High Superheat = Starved Evaporator

Low Superheat = Flooded Evaporator

Read more

[4uzindian]

to  niobrara : soon as it's cool enough i'm going to chek and clean ev coils.the outside unit model is arcoaire #R2A330GKC1 . the attic unit is from 1998 comfort maker model # EXM36F19A1 . don't know what 410 or 22 coil is. soon as ido this i will post . TO  JUMPTROUT51:i'll check and clean what i can.   to  jwwebster:your answer is obviusly for a tech. i'll do what i can .then i'll post . what is the a coil ? i hope to get to this this week  so i will be posting. thank's for the reply.                                                                                                                               

[jumptrout51]

The "A" coil is the evaporator coil inside the air handler.
Why was the condensing unit changed out?
What symptoms?
Check all the things I posted and let us know what you find out.

[4uzindian]

to all: i'm not a tech so superheat and such i can't test.what i did today is tape up two small openings in the duct that goes into the air handler unit where the a- coil resides. i didn't compare temp output from room ceiling vents. but it seems a little better than yesterday. i'm in trenton nj. so were in a heat wave . the attic is around 110 112 degrece. friday morning i hope to take off the panel to get to the a- coil. i'll spray it with the coil cleaner and flush with hose. my next move i'm thinking i'll wrap the whole condesing unit with visquen plastic and tape.this could take a while ? i'm going to do the jumpp trout stuff first. as for jwwebster i'd need a tech for those kind of test. TO JWwebster im not to yours yet but how do you adjust the a- coil ? would that be by adding or taking out the freon charge ? back tomorow hopefully.

[JWWebster]

If you want the system tuned properly so that the new condenser matches the old air handler you gonna need to check superheat and subcooling to see what is going on with it. Here is Dr Z with a nice Video:

[4uzindian]

friday 7-6 .didn't get to a coils today hopefullt saturday. will post again. i'll watch the video.

[JWWebster]

Get you some NO RINSE coil cleaner. Remove as much of the lint, hair, and dust you can with a soft bristle brush. Go by directions on can. Basically you turn off the system. Apply the spray. Let it foam up and pull out deep down grime. Be ready with towels if you do not want it to go everywhere. Wait 10 minutes then turn the unit back on. The foam will go down the drain and clear it out also. Go by directions on can. Get it online or at an HVAC distributer near you.

http://www.grainger.com/Grainger/NUCALGON-Aerosol-Evaporator-Coil-Cleaner-2RZW3

[4uzindian]

first i'd have to pay a tech to check super heat and sub cooling. i do understand you explanation on the two measurements. it has to be one of these.i'm thinking about calling a tech. today i re sealed some small openings in the duct work behind the evap coils. i put my hand on the evap coils they were just about cool. i know they should be cold.it's 100 today in trenton. the outside unit was 12 years old and was diagnosed with a bad compressor.the fan is blowing strong.the coils were clean. when all was working there was a lot of water coming out the drain outside. now theres hardly any. iused that coil cleaner you mentioned last season. about the evap unit in attic. how cold should the evap coils be. also the small line going into the evap should it be cold or hot?it's 3:30 pm outside small line is hardly warm the big line is slightly cool and seaty. water is just dripping from drain pipe. upstairs small line is slightly warm big line is slightly cool.

[JWWebster]

The small line is the high side. It should be hot. The larger line should be cold.

[4uzindian]

sunday: the lines are not the temp they should be. you think i should call a tech and let him try to adjust the unit ?

[JWWebster]

Yep. Might need a sharp HVAC person on this one though. Better get a pro.

[4uzindian]

i'm most likely going to get a tech to try and fix this. i'll surley post to let you know. thanks very much for your answers and time. i will call afeww differt places and see who i think sounds like they can fix everything. i'm going to lay off this post for right now. thank's again.