What is a “Building”, System” and “Zone”, “Multiple zones” as defined in HLCP?
Energyplus input is from a thermal model made by the user, from the building geometry inputs. Output is of the thermal model only. A “zone” is a thermal, not a geometric, concept. A “zone” is an air volume at a uniform temperature plus all the heat transfer and heat storage surfaces bounding or inside of that air volume. EnergyPlus calculates the energy required to maintain each zone at a specified temperature for each hour of the day. Since EnergyPlus performs a zone heat balance, the first step in preparing a building description is to break the building into zones. The objective of this exercise is to define as few zones as possible without significantly compromising the integrity of the simulation. Geometrical Zones: (Pic courtesy Energyplus) Thermal Zones: (Pic courtesy Energyplus) The minimum number of zones in a general simulation model will usually be equal to the number of systems serving the building. Thermal model: Sketched by HVAC engineer.
