Source code for pythermalcomfort.models.work_capacity_iso
from __future__ import annotations
import numpy as np
from pythermalcomfort.classes_input import WorkCapacityStandardsInputs
from pythermalcomfort.classes_return import WorkCapacity
[docs]
def work_capacity_iso(
wbgt: float | list[float],
met: float | list[float],
) -> WorkCapacity:
"""Estimate work capacity due to heat based on ISO standards as described by Brode
et al.
Estimates the amount of work that will be done at a given WBGT and
intensity of work as a percent. 100% means work is unaffected by heat. 0%
means no work is done.
The function definitions / parameters can be found in: 1. Bröde P, Fiala D,
Lemke B, Kjellstrom T. Estimated work ability in warm outdoor environments
depends on the chosen heat stress assessment metric. International Journal
of Biometeorology. 2018 Mar;62(3):331 45.
For a comparison of different functions see Fig 1 of Day E, Fankhauser S, Kingsmill
N, Costa H, Mavrogianni A. Upholding labour productivity under climate
change: an assessment of adaptation options. Climate Policy. 2019
Mar;19(3):367 85.
Parameters
----------
wbgt : float or list of floats
Wet bulb globe temperature, [°C].
met : float or list of floats
Metabolic heat production in Watts
Returns
-------
WorkCapacity
A dataclass containing the work capacity. See
:py:class:`~pythermalcomfort.classes_return.WorkCapacity` for more details. To access the
`capacity` value, use the `capacity` attribute of the returned `WorkCapacity` instance, e.g.,
`result.capacity`.
"""
# Validate inputs
WorkCapacityStandardsInputs(wbgt=wbgt, met=met)
wbgt = np.asarray(wbgt)
met = np.asarray(met)
met_rest = 117 # assumed resting metabolic rate
wbgt_lim = 34.9 - met / 46
wbgt_lim_rest = 34.9 - met_rest / 46
capacity = ((wbgt_lim_rest - wbgt) / (wbgt_lim_rest - wbgt_lim)) * 100
capacity = np.clip(capacity, 0, 100)
return WorkCapacity(capacity=capacity)