Hvac is full of challenging subject. But don’t think it’s tough subject. Once if your understand the methodology and Concept you can easily beat all the challenges.

Need to study the complete building properties suppose if your failed the cooling load calculation it will be trouble in future.

Also need to calculate all the Hvac related calculation and choose the right equipments. The following things you should take care

  1. Cooling load
  2. External static pressure
  3. Pump head
  4. Pressurization calculation.
  5. Proper duct design with velocity or head loss based sizing.