Weak Central Air Cooling problem

- L
- Lin0
  
  Contact options for registered users
posted
17 years ago

Sat, Jul 1, 2006 1:01 PM

everyone,

I ran into a post here and it concerns my problem of my A/C not cooling my home down sufficiently:

Quote: I would consider 30F condenser dT to be the upper limit on older low SEER units, beyond which there is an airflow problem. On the newer high SEER units, I would draw the line at 25F dT.

The lower limit would depend primarily upon load. I would think it should be about 15F dT or above.

Here is the list of temps I use for online trouble shooting.

Low side:

Evap air in temp =3D 66=B0F Evap air out temp =3D 48=B0F SST (saturated suction temp) - Where is this measured and how? Suction line temp near compressor =3D 35=B0F

High side: (I'll get these soon)

Cond air in temp - Cond air out temp SCT (saturated condensing temp) Liquid line temp near condenser

------------------------------------------------------

description of my system:

2 Ton Copeland Hermetic Recipricating compressor (inside a 1987 seer 8 condenser) 1980 Tappan furnace 1953 brick ranch style house, with insulated attic and insulated basement, about 1100 sq ft

Performed a test yesterday with monitoring temperatures becuase it was very calm and stable outdoor air temps today

Outdoor air temp was 81 from 1pm to 5pm Inside air temp started at 76.8=B0F @1pm inside air temp ended at 75.2=B0F @5pm ATTIC AIR TEMP was over 103=B0F during all the hours Every half hour the main floor temp only dropped about .18=B0F during these hours. Humidity on main floor was 42% at 1pm, and dropped to 38% by 5pm

What would you guys call a low seer unit?

couple more things: the temps that are listed in the quoted text are from my current setup, I just inserted them thats all. I replaced the furnace blower motor. The compressor is new (few days) Basement temp is very close to main floor temp (couple degrees difference(which I think rules out any bad ducting leaks)) AND when the return air is 72=B0F, the output air from any room vent is

57=B0F

Are these okay temps? I want my house temps to fall at little higher rate when the system runs. Like for example, it never shut off in those

5 hours as my target temp was 72=B0F !!!

~Will

Loading thread data ...

- D
- DIDO
  
  Contact options for registered users
Vote on answer
posted
17 years ago

Sat, Jul 1, 2006 3:25 PM

I ran into a post here and it concerns my problem of my A/C not cooling my home down sufficiently:

Quote: I would consider 30F condenser dT to be the upper limit on older low SEER units, beyond which there is an airflow problem. On the newer high SEER units, I would draw the line at 25F dT.

The lower limit would depend primarily upon load. I would think it should be about 15F dT or above.

Here is the list of temps I use for online trouble shooting.

Low side:

Evap air in temp = 66°F Evap air out temp = 48°F SST (saturated suction temp) - Where is this measured and how? Suction line temp near compressor = 35°F

In my opinion what you have is not enough of air flow accros the cooling coil, it also looks that perhaps is some what overcharged but your suction temperature will change if you can increase air flow Dido say that!

High side: (I'll get these soon) Cond air in temp - Cond air out temp SCT (saturated condensing temp) Liquid line temp near condenser