A/C up to par?

tima2381

I'm in a new house (~ 1700 sqf) with Goodman A/C system (CSCF4860N6AA coil, GSC130421AA compressor). On a hot, sunny day like today, with outside temp 94F, the A/C runs continuously to keep the inside temp at 75F. This seems not as good as what I've had before. At the return, I measure the incoming air temp as 73F. At the nearest register, I measure the output air temp as 60F, and that's about an 8' duct run with R4.4 flexible duct. At a vent perhaps twice the distance, I measure 61F. At a vent much farther away, I get 64F. So I'm getting a maximum drop of 13F and a minimum of 9F. At night, the maximum drop is about 18F. Does any of this indicate a problem?

bigMikeB

I would think if the charge was correct and the airflow was right you would get a 20F split across the system. There maybe issues with the ducts being insulated poorly. A 13F change is pretty poor performance.

tima2381

Let me ask you something else. When room doors are shut, I feel a powerful draft coming from beneath them and really all around their perimeter. The master bedroom is located on the other side of the house, and the draft is really noticeable there. (Inside the room with the door closed, the noise level increases quite a bit due to this.) I don't seem to recall this sort of thing in places I've lived in previously.

I have a single 24x24" return located in a hallway and 10 6x12" registers. Is this mismatched, and could it affect the efficiency? If so, what could be done to solve it?

bigMikeB

The doors should be trimmed to allow air to move more freely. One return is the way most residential companies save some work and lower their price. You need air in (return) to get air out (supplies). Yes, it is a factor in changing the temp in the house faster.

wardb

my Lennox 80UHG(x) HVAC puts out cold air, but the amoutn of air comming out of the vents is VERY low. I notice in the install book there is a heat speed and cooling speed to the blower. could the blower be on the wrong speed. It sounds like it is going like crazy?

MechanicalDVR

It is possible but not probable. Is the filter clean? Has the unit put out more airflow in the past? If it has done better in the past, the coil maybe dirty. Has the duct work been changed? More info is needed before anymore can be said.

__________________
100% Union and proud of it.