The HAP System Design Load application allows you to estimate the cooling and heating loads for commercial buildings in order to facilitate HVAC system design. It works together with other HVAC programs and it helps you to select the system fans, central cooling and heating coils, air terminal equipment, space heating coils, preheat coils, and central chiller. Also, it can analyze the return plenum loads, the impact of duct leakage, the morning pulldown loads, the effects of thermostat throttling range on zone cooling loads, the building orientations at any of 16 principal exposures and so on. You can find all its feature on the official web page. In order to use the software, you will need to check its user manual. You can find it in the Help menu, or you can request it from the developer.