I just completed my first try at the HVAC-Calc Residential 4.0 for a new home. My results came out as:
Sensible gain: 53,545
Latent gain: 14,030
Total heat gain:67,575 (5.5 tons)
Total heat loss: 33,464

I have been trying to determine if a zoned system is a good option, and that is one reason why I wanted to do a Manual J calculation, to see if one unit could handle the house. Based on my first try the heat gain is too much for one 5 ton AC unit.

Here's my question (don't laugh too hard):

When the program asks for how many people are in a particular room I estimated maximum head count for each room at any particular time, although it is highly unlikely that that many people would ever be in the house at the same time. For example, I put 5 in the kitchen, 4 in the nook, 10 in the family room, 8 in the dining room, 2 in a hallway, etc.

The total heat gain for the "people" component is 29,150, and that is what prompts the question. 29,150 represents 43% of the total gain, so I'm thinking maybe I should not use the total capacity for each room simultaneously.

If I have mistakenly loaded up each room too high then perhaps the total heat gain may fall into a 5 ton range.