I put in a 4 ton 14 Ser Trane unit. Temp is 73 inside- How do I get it to 64 deg?- Vent temp is 58 degrees?
Answers:
A 4-ton unit provides anywhere from 44000 to 48000 BTU of cooling. If your house gains very close to this amount of heat due to sun or other load, you will not likely be able to cool it to 64. Remember a unit is sized to cosely match what is gained. Too much cooling power causes a spike in indoor humidity and that makes you feel clammy instead of cool. To little cooling power and you get hotter and hotter.
A VERY GOOD reason NOT to cool to 64 degrees is condensation. Surfaces at 64 degrees will ALMOST always cause condensation to form when outside air of almost any relative humidity and temperature over 74 degrees hits it. That means, when the air leaks in around your light fixture because remember that is a hole to your HOT attic, it will condense there and MOLD will grow. You will be wondering why you have mold everywhere and it will be because you are watering it and nurturing it. :)
If you really need ONE room with a low temperature for medical reasons or something, I would do as another suggested and buy a window UNIT WITH OUTSIDE AIR. OUTSIDE AIR is important here. That means a window unit that also introduces a litle bit of outside air as it cools.
That way, you will be blowing more air into the room than you are taking out causing positive pressure in the room keeping that attic air we talked about earlier from wanting to come in. You'll be sucking air in form the holes. That will help you from having MOLD EVERYWHERE.
Good luck with it all.
BTW-
I have 10 tons of ac in my house but use a mini split in my master suite to keep it a chilly 68 even when it 106 outside. How expensive is to replace a flat roof of a building that uses a membrane?