We just had a new inside and outside unit put in. And it is so hot. They have came back to our house and said everything is fine. But it gets 83deg in the middle of the day. Our ac only cools it down at night.

Is the unit large enough for the house? If it's too small, then it doesn't matter if it's in perfect working order, it won't cool the place down.

Well our house is 1400 sq ft. And the unit is 2.5 ton. Both outside and inside

House will cool down to desired temp. Call installer back and insist the check it out properly. Something is not right and they should take care of it.

I would call them back out and have then check the temperature differential across the evaporator coil, there should be 20 degrees, also tell them to come in the mid afternoon when it is hot.