A Python library for HVAC engineering:
- cooling and heating load calculations of buildings
- estimation of energy needs and energy consumption
- design and analysis of air and hydronic distribution systems
- air conditioning process calculations
- simulation and analysis of heat exchangers (limited for now to plain fin-and-tube heat exchangers)
- simulation and analysis of single-stage vapor compression machines and VRF systems
- sizing of refrigerant piping
- correlations for convection heat transfer coefficients and friction factors
Example scripts and notebooks can be found under docs/examples. More examples
will be added over time.
Note
This project replaces the older project HVAC, which is no longer under
development and will be no longer maintained.
At this moment the following subpackages are part of hvac:
air_conditioning
A package about air-conditioning processes and systems.
cooling_load_calc
A package for doing cooling load calculations of a building, based upon ASHRAE's
Radiant-Times-Series (RTS) method.
It uses a lumped capacitance model to take the thermal inertia of flat, opaque
building components and the interior thermal mass of a zone into account.
This package uses the subpackage sun, also included in the main package
hvac. This subpackage is used to calculate the solar radiation incident on
exterior surfaces and the solar heat gain through windows.
Subpackage sun implements the equations in chapters 1 and 2 of Duffie,
J. A., Beckman, W. A., & Blair, N. (2020). SOLAR ENGINEERING OF THERMAL
PROCESSES, PHOTOVOLTAICS AND WIND. John Wiley & Sons.
heating_load_calc
A package for doing the heating load calculation of a building based on the
method of European standard EN 12831-1 (July 2017).
energy_estimation
Estimation of the energy consumption of a building using the bin table method.
fluid_flow
A package about fluid flow in pipes and ducts and for designing and analyzing
pipe and duct network systems. It includes a large number of fittings taken
from Crane's TECHNICAL PAPER NO. 410M and SMACNA's HVAC SYSTEMS DUCT DESIGN
MANUAL.
refrigerant_piping
Package for sizing refrigerant lines (suction line, discharge line, and liquid
line) between an outdoor unit and indoor unit of an air conditioning system.
heat_transfer
This package implements a number of correlations for calculating convection
heat transfer coefficients and friction factors for different geometries. Most
correlations were taken from Nellis G. F. , & Klein S. A. (2021).
INTRODUCTION TO ENGINEERING HEAT TRANSFER. Cambridge University Press.
heat_exchanger
Originally (and still) part of the subpackage heat_transfer, but a rewritten
package has also been added as a subpackage of the main package
hvac. It implements the effectiveness-NTU method for both dry and wet
external heat transfer surfaces, and it contains rating and sizing procedures
for some fin-tube heat exchangers, which are applicable to single-phase fluid
flow, and which are implementations of the procedures described in Shah,
R. K. , & Sekulic, D. P. (2003). FUNDAMENTALS OF HEAT EXCHANGER
DESIGN. John Wiley & Sons.
vapor_compression
Furthermore, subpackage heat_transfer.heat_exchanger.fin_tube also contains
a model for a plain fin-tube, counter-flow air evaporator and similar air
condenser. These models are used together with a model for a fixed or variable
speed compressor in the module machine of subpackage vapor_compression.
Purpose of this module is to simulate the steady-state performance of a
single-stage vapor compression machine (air conditioning machine, heat pump).
Several application examples have been included in the folder vapor_compression
of docs/examples.
vrf_system
This subpackage can be used to model a VRF-system in relation to the building
in which it is installed, with the purpose to estimate its energy consumption
during a typical heating or cooling season. An example of such an energy
consumption estimation and a comparison between different candidate VRF-systems
in relation to the same building have been included in the folder vrf_system
of docs/examples.
Besides the aforementioned application-oriented packages, hvac also includes a
number of more basic subpackages which are used throughout the modules of
hvac:
First of all, hvac is heavily based on third-party library pint for
working with physical quantities in Python. Module pint_setup.py inside hvac
does the necessary setup for using Pint's Quantity class throughout the
package. When you write a script using package hvac, simply write from hvac import Quantity to work with physical quantities in your script.
Subpackage fluids contains a number of modules with classes that act like
object-oriented wrappers around third-party libraries CoolProp and aipws.
The principal classes of fluids, that are used extensively throughout
the code, are Fluid and HumidAir, which encapsulate CoolProp's API and
allow to accept Quantity objects.
Finally, subpackage charts contains a package matplotlibwrapper, being a
tiny wrapper around third-party library matplotlib, meant to ease the drawing
of some frequently used chart types. It also contains a module to plot
refrigeration cycles on the log-p-h diagram of a refrigerant and a module to
plot air conditioning processes on a psychrometric chart.