I replaced an old condenser with another old condenser. I didn't buy new because I wanted to get another summer out of this AC before replacing the entire system. Inside I have a Goodman evap coil with a fixed piston and outside a Lennox Elite condenser both rated at 4 tons. As for the size of the piston in the evap coil, I went off of Goodmans sizing chart for their pistons and installed a .080 piston. I paid someone to braze the old lineset to the condenser. I vacuumed and pressure tested the lineset before releasing the refrigerant (R410a) into the system. After running the system, I could tell the air was not getting very cold and took some measurements.
The temperature at the supply vent closest to the evap coil was 70 degrees. The temp at the return register, right next to the air handler, was 76 degrees. The temp outside was around 77 degrees. The low side reading on the my manifold gauge read 120 psig which would be about 40 degrees inside the evap coil. There is no restriction in air flow.The difference in temperature between the air entering the evap coil vs the air coming out of the coil is only about 6 degrees. I think this difference should be around 20 degrees.
Do you guys think the problem could be the size of the fixed piston I installed. If I put a larger piston in the evap coil, it would allow more refrigerant in. With more refrigerant running through the coil it would allow more heat to be absorbed from the air moving over the coils. Not sure if the way I'm thinking about this is correct or not. I would appreciate any suggestions. Thanks for any help.
The temperature at the supply vent closest to the evap coil was 70 degrees. The temp at the return register, right next to the air handler, was 76 degrees. The temp outside was around 77 degrees. The low side reading on the my manifold gauge read 120 psig which would be about 40 degrees inside the evap coil. There is no restriction in air flow.The difference in temperature between the air entering the evap coil vs the air coming out of the coil is only about 6 degrees. I think this difference should be around 20 degrees.
Do you guys think the problem could be the size of the fixed piston I installed. If I put a larger piston in the evap coil, it would allow more refrigerant in. With more refrigerant running through the coil it would allow more heat to be absorbed from the air moving over the coils. Not sure if the way I'm thinking about this is correct or not. I would appreciate any suggestions. Thanks for any help.
