The Carrier guy said he doesn't need to know any of that information and I was looking to install a greenspeed. all he said to me was he recommends a performance model and it is more common. he asked me to send him the house plans.

The Whestinghouse said I needed a 3 ton without a load cals.

I cant get a response from anyone when I ask them to do a load cals.

What do I do when I can't install it myself.

I know I need a 2 ton for cooling and a 2 ton for heating, I would like to have a 2.5 ton for heating in the northing environment.

I have a heat gain of 21475 and a heat loss of 24672. this is baesd on 7 degrees. so a 2 ton is all I need.

Everyone here seems to go by rule of thumb.