Field-Ready · System Review
How It All Connects
Plants, air handlers, terminal units, and zones: the full chain from energy source to conditioned space.
One Building, One System
You have spent the last four series learning individual pieces: VAV boxes, reheat coils, RTUs, built-up AHUs, hot water plants, chilled water plants. Each lesson treated them as their own thing. That made sense at the time. But on a real job, none of these exist in isolation.
A VAV box needs conditioned air. That air comes from an AHU. The AHU needs cold water to cool it and hot water to heat it. The cold water comes from a chiller. The hot water comes from a boiler. When the zone is cold and the VAV reheat coil fires, it is drawing from the same hot water loop as the AHU preheat coil across the building. All of it is connected. All of it is running at the same time.
The diagram below shows a simplified version of that complete picture: one chilled water plant, one hot water plant, one AHU, and two VAV boxes serving two zones. This is the skeleton of most commercial buildings you will commission.
Nothing here is new. You have seen every one of these components. This is just the first time you are looking at all of them at once.