Simple Simple

Your dream house come true!

A simple Building Energy Model written in Python.

Conceptual Model

The model is derived from the hourly dynamic model in ISO 13790. It has only one capacity and one resistance.

Compared to the ISO 13790 there is

• no internal heat gain,
• full shading of the building, no direct or indirect sun light,
• no windows or doors,
• no ventilation,
• immediate heat transfer between air and surface.

θ_m,t = θ_m,t-1 × (1 - Δt / C_m × H_{tr, em}) + Δt / C_m × (Φ_{HC, nd, t-1} + H_{tr, em} × θ_{e, t-1})

Output Variables

• Φ_{HC, nd, t}: cooling or heating power at time t

State Variables

• θ_{m, t}: building temperature [℃] at time t

Parameters

• θ_{e, t}: outside temperature [℃] at time t
• A_f: conditioned floor area [m²]
• C_m: capacity of the building's heat mass [J/K]
• Δt: time step size [s]
• H_{tr, em}: heat transmission to the outside [W/K]
• θ_{int, C, set}: cooling set point temperature [℃]
• θ_{int, H, set}: heating set point temperature [℃]
• Φ_{C, max}: maximum cooling power [W]
• Φ_{H, max}: maximum heating power [W]

User Guide

Installation

You need Python 3.6 and pip installed.

Install from GitHub (needs Git):

$ pip install git+git://github.com/timtroendle/simple-simple

If you don't have Git installed, download and extract the repository and then execute:

$ cd <simple-simple-directory>
$ pip install -e .

Usage Example

from datetime import timedelta
from simplesimple import Building

conditioned_floor_area = 100
building = Building(
    heat_mass_capacity=165000 * conditioned_floor_area,
    heat_transmission=200,
    maximum_cooling_power=-10000,
    maximum_heating_power=10000,
    initial_building_temperature=16,
    time_step_size=timedelta(minutes=10),
    conditioned_floor_area=conditioned_floor_area
)

# simulate one time step
print(building.current_temperature) # returns 16
print(building.thermal_power) # returns 0
building.step(outside_temperature=20, heating_setpoint=18, cooling_setpoint=26)
print(building.current_temperature) # returns ~16.4
print(building.thermal_power) # returns 10000

Developer Guide

Installation

Best install simplesimple in editable mode:

$ pip install -e .

Run the test suite

Run the test suite with py.test:

$ py.test