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omoeseso
08-09-2009, 12:06 AM
I just recently moved to Miami from West Palm Beach because my girlfriend is attending the university of miami school of law. Well that all being said i still live in west palm beach because i work for an air conditioning company. Im not a service technician but i work in the office... Unfortunately the air conditioning company that i work for does not go down this far. So my landlord had an A/C guy come to the house and check it out. These are my issues.

I live in a 2 story duplex on the 2nd floor the house was built in the 40's i have noticed that the attic has no insulation whats so ever!!! My squarefootage is 700 and theres a 5 year old 2Ton Rheem in here. After the A/C guy left here this is the information he gave me.

Outlet 68 degree's
Inleft to A/H 83 degree's
81 at the Tstat but set to 77degrees
Anbient tempature 92 degrees

Pressures 85low, 254high.

Iv never heard of this but.
54
-71
= 19 degree superchoat.

He says that A/C is running to manufacture specs. And doesnt the TD seem a little low? Also we are having an insulation company blow R30 this thursday. Maybe the heat low is high during the day because there is no insulation. I dunno thats why im turning to you guys for your help. The A/C runs all day during the day and will only keep the tempature till about 11am then it goes up in the afternoon. Then finally at 1am in the morning it will turn off when it goes to 76degrees and operate normally.

amd
08-09-2009, 01:18 AM
Temperature drop in itself can not be used to determine if a system is running at capacity.

High indoor humidity can reduce the temp drop; wetbulb return/supply temperatures and airflow measurements are required to calculate system capacity.

The blower speed might be too high.

Iv never heard of this but.
54
-71
= 19 degree superchoat.

If you meant superheat, 19 might be a little high at 83F if it's dry; I can't tell without the wetbulb return air temp. The other numbers look okay.

Edit: I assumed that the metering device is fixed; if it's a TXV you could have a major problem.

Also we are having an insulation company blow R30 this thursday.

That will make a huge difference.

The A/C runs all day during the day and will only keep the tempature till about 11am then it goes up in the afternoon. Then finally at 1am in the morning it will turn off when it goes to 76degrees and operate normally.

For the record, running continuously for several hours is normal during hot weather.

udarrell
08-09-2009, 10:53 AM
Clipped...
So my landlord had an A/C guy come to the house and check it out. These are my issues.

I live in a 2 story duplex on the 2nd floor the house was built in the 40's i have noticed that the attic has no insulation whats so ever!

My squarefootage is 700 and theres a 5 year old 2Ton Rheem in here. After the A/C guy left here this is the information he gave me.

Five years old, appears to be a 10-SEER?

Outlet 68 degree's
Inleft to A/H 83 degree's 15-F indoor temp-split
81 at the Tstat but set to 77degrees
Anbient tempature 92 degrees

Pressures 85-psig suction.
254-psig head 119-F Condensing Temp minus 92-F outdoor temp= 27-F Temp-rise. A bit high for a 10 or 12-seer, but could be okay depending on indoor humidity level.

I never heard of this but.
54 -71= 17-F degrees superheat.
-------------
Suction 85-psig is 51-F SST SLT 71 = 20-F Superheat.
High for 92-F outdoor temp.

Is unit & both SA & RA in the attic; not well enough insulated.
Blower CFM too high?

Could be drawing hot attic air into Return-Air.

Could be a little low on charge when heatload is higher, starving E-Coil.

Liquid-line Subcooling would reveal that, but NO liquid-line temp taken!

He says that A/C is running to manufacture specs. And doesnt the TD seem a little low? (See above items that need checking.)

Also we are having an insulation company blow R30 this thursday. Maybe the heat load is high during the day because there is no insulation. I dunno thats why I'm turning to you guys for your help. The A/C runs all day during the day and will only keep the tempature till about 11am then it goes up in the afternoon. Then finally at 1am in the morning it will turn off when it goes to 76degrees and operate normally.
The insulation will help a lot, but seal everywhere possible to reduce air infiltration, but only to safe levels. - Darrell

omoeseso
08-09-2009, 11:43 AM
The A/H is vertical in a closet. A few days after we moved in i noticed the crappy filter they in the unit was really dirty. I ordered from work antimicrobial sponge filter. The evap coil was a little dirty so i brushed some of the debris away.

Im not sure what seer the system is but maybe u will know by the model and serial numbers

Model #14AJ06501C01 OR RCBA2457G
SERIAL # M520500409

Like i said at night time it seems to work fine. But during the day it just runs and runs and runs and doesnt keep temp... I dont know maybe the fan speed is just set real high. If i need to adjust witch wires on the fan switch do i need to change around?

beenthere
08-09-2009, 12:30 PM
Put a regular blue fiberglass air filter in.
And see if that makes a difference.