HVAC tab in model data - Compact HVAC
This data is only visible at zone level and only when the Manual sizing model option is selected. The Cooling capacity can either be entered by hand or can be autosized using the Cooling Design Calculations. If, immediately prior to a Simulation the Cooling capacity has not been entered (neither by hand nor from a previous Cooling Design Calculation) then a Cooling design autosizing simulation is started to calculate the capacity. The Plant sizing building model option controls the way this works.
You can change cooling capacities by hand if you wish but you should bear in mind that, by default, if Model Options change, all heating and cooling capacities are reset to zero. Set the Plant sizing model option to 2-Manual to avoid this happening.
A single set of cooling plant data is required per building and all unitary zones in the building refer to this data when plant fuel consumption is calculated.
This data is only visible at building level (even for Unitary single zone systems), that is all unitary cooling systems in the building must use the same fuel. Select the type of fuel used to generate the heating energy - choose from:
| Interface Fuel Name | Fuel in results |
| 1-Electricity from grid <default value> | Electricity |
| 2-Natural Gas | Gas |
| 3-Oil | Oil |
| 4-Coal | Solid fuel |
| 5-LPG | Bottled gas |
| 6-Biogas | Bottled gas |
| 7-Anthracite | Solid fuel |
| 8-Smokeless Fuel (inc Coke) | Solid fuel |
| 9-Dual Fuel Appliances (Mineral + Wood) | Other |
| 10-Biomass | Other |
| 11-Waste Heat | Other |
You should select 1-Electricity from grid you wish the results displayed in DesignBuilder to agree with those calculated by EnergyPlus directly and displayed on the Summary tab of the Simulation screen.
This data is only visible at building level, that is all Unitary cooling systems have the same CoP. The cooling system coefficient of performance is used to calculate the fuel consumption required to meet cooling demand. The value represents the total seasonal efficiency of the entire cooling system and should include the effect of all energy consumption associated with building cooling such as fan and pump energy, chiller inefficiency, control equipment etc.
You should enter a value of 1 if you wish the results displayed in DesignBuilder to agree with those calculated by EnergyPlus directly and displayed on the Summary tab of the Simulation screen.
This data is only visible at building level, that is all Unitary cooling systems have the same distribution loss. An additional loss accounting for the loss of cooling to outside due to distribution of chilled fluids through the building. It acts in combination with the CoP to increase the fuel consumption based on the cooling load.
You should enter a value of 0 if you wish the results displayed in DesignBuilder to agree with those calculated by EnergyPlus directly and displayed on the Summary tab of the Simulation screen.
This schedule data is used in conjunction with the cooling setpoint temperatures on the Activity tab to define the time-varying cooling setpoint schedule in the zone. The operation schedule defines the times when full and setback setpoints should be met and the setpoint data on the Activity tab define the actual setpoint values. See Defining setpoint temperature schedules for more on this.