a/c unit

[cobia13]

i recently had a 3 1/2 ton a/c unit installed (trane). i have two zones. house (1) & sun porch (2). when it hot outside 90 +, i can not get the house below 78. i have the thermo set at 75. there is a return on the sun porch that also draws air along with the return in the house. i have had the installer look at the installation many times and i can't get an answer why the house will not get cool. thay have said that the thermo on the porch should be set a fews degrees above what the house is set out. this way, hot air will not be drawn thru the unit. it ain't working. any ideas?thks in advance

Ivan

 

[Steve]

I wouldn't try to cool a "sun porch". Instead have plenty of opening windows. Save your cooling capacity for the house.

Have you tried shutting off the vents to the sun porch?

 

[cobia13]

i haven't tried that because when the house (zone 1) is running and zone 2 is not, there is a air duct flapper valve that shuts off zone 2. if the temp in the sunroom goes above what the thermostat is set at in will open and cool the room. it will cool the sun porch great but it isn't worth a flip when it comes to cooling the house.
rgrds
ivan