Direct expansion systems
Direct expansion systems include variable refrigerant flow (VRF) systems and multisplit systems which are connected to the corresponding direct expansion terminal units.
Other direct expansion systems such as 1x1 splits or compact units are modelled as stand-alone terminal units and do not require the introduction of an air-conditioning system in the specific section.
VRF
Generic
Characteristics
- With heat recovery (3 pipe) (optional)
- Fuel type (Electricity / Natural gas / LPG / Diesel / Coal / Biomass / Densified biomass (pellets))
Cooling
- Gross rated total capacity (optional)
Allows users to specify a value for the gross rated total capacity of the cooling unit. - Nominal cooling COP
- Advanced configuration
- Minimum outdoor temperature in cooling mode
- Maximum outdoor temperature in cooling mode
Heating
- Gross rated capacity (optional)
Allows users to specify a value for the gross rated capacity of the unit in heating mode. - Gross rated heating COP
- Advanced configuration
- Rated heating capacity sizing ratio
- Minimum outdoor temperature in heating mode
- Maximum outdoor temperature in heating mode
Refrigerant pipes
- Vertical height used for piping correction factor
- Equivalent piping length used for piping correction factor in cooling mode
- Equivalent piping length used for piping correction factor in heating mode
Condenser
- Condenser type (Air cooled / Water cooled / Evaporatively cooled)
Heat recovery mode
- Minimum outdoor temperature in heat recovery mode
- Maximum outdoor temperature in heat recovery mode
Control
- Minimum part load ratio
- Control of the operating mode (Load priority / Zone priority / Thermostat offset priority / Master thermostat priority)
- Zone name for master thermostat location
Defrost mode
- Defrost strategy (Resistive / Reverse cycle)
- Resistive defrost heater capacity
- Control (Timed / On demand)
- Heat pump defrost time period fraction
- Defrost mode maximum outdoor temperature
Compressor crankcase heater
- Crankcase heater power per compressor
- Number of compressors
- Ratio of compressor size to toal compressor capacity
- Maximum outdoor temperature for crankcase heater
DManufacturer
Outdoor unit
- Open BIM Database unit selection
Allows users to select a variable refrigerant flow system outdoor unit from the manufacturers and models available in the Open BIM Database.
Refrigerant circuit
- Equivalent pipe length between the outdoor unit and furthest indoor unit
The length of the refrigerant pipes is used to correct the output of the VRF system, according to the manufacturer's instructions. - Maximum height difference between the outdoor unit and indoor units
The height difference between units is used to correct the power of the VRF system, according to the manufacturer's instructions. The height difference is indicated with a positive sign if the outdoor unit is installed above the indoor units and a negative sign if the outdoor unit is installed below the indoor units. - Control of the operating mode (Load priority / Zone priority / Thermostat offset priority / Master thermostat priority)
- Zone name for master thermostat location
Multisplit
Manufacturer
Outdoor unit
- Open BIM Database unit selection
Allows users to select a variable refrigerant flow system outdoor unit from the manufacturers and models available in the Open BIM Database.
Refrigerant circuit
- Control of the operating mode (Load priority / Zone priority / Thermostat offset priority / Master thermostat priority)
- Zone name for master thermostat location
- Total pipe length
