1. Refrigerant Properties
The DuPont Refrigerant Expert DUPREX 3.0 uses the most recent version of the NIST Standard Reference Database 23, REFPROP Version 8.0 to calculate thermodynamic and transport properties of refrigerants. This program, developed by the National Institute of Standards and Technology (NIST) provides tables and plots of the thermodynamic and transport properties of industrially important fluids and their mixtures with an emphasis on refrigerants and hydrocarbons.
It is based on the most accurate pure fluid and mixture models currently available. It implements three models for the thermodynamic properties of pure fluids: equations of state explicit in Helmholtz energy, the modified Benedict-Webb-Rubin equation of state, and an extended corresponding states (ECS) model. Mixture calculations employ a model that applies mixing rules to the Helmholtz energy of the mixture components; it uses a departure function to account for the departure from ideal mixing. Viscosity and thermal conductivity are modeled with either fluid-specific correlations, an ECS method, or in some cases the friction theory method.
2. Conversion Tool
This excel based program allows you to make conversions between a wide array of measurement units.
Conversion Tool is pre-configured with over 2000 units in more than 78 categories, which range from those that are common, such as length, volume, velocity, mass, and pressure, to more specialized categories like specific heat mass flow rate which are important parameters in defining the working of HVAC.
Excel format of the conversion tool
3. Pipe Cal
Proper piping is one of the most crucial elements in deciding the performance of an air conditioner. It not only acts as a means for refrigerant to reach compressor from evaporator, but also provides the way for oil to drain back to the compressor.
Three primary issues that drive pipe sizing are velocity, pressure drop, and refrigerant charge. When determining the size of suction lines, the line must be kept large enough to minimize pressure drop, which minimizes capacity loss, but small enough to keep velocities to enable oil to return to the compressor.
Liquid lines must be large enough to minimize pressure drop, but small enough that the extra refrigerant they hold will not damage the compressor.
Keeping note of these factors, Pipe Cal- calculates pipe sizing and capacity deration using Haaland equation.
This software can calculate:
- Equivalent length of elbow and pipe
- Suction tube
- Liquid tube
- Quantity of suction U-trap
- Refrigerant charge to be added
- Capacity deration
