ladybug_comfort.parameter.pmv module

Parameters for specifying acceptable thermal conditions using the PMV model.

class ladybug_comfort.parameter.pmv.PMVParameter(ppd_comfort_thresh=None, humid_ratio_upper=None, humid_ratio_lower=None, still_air_threshold=None)

Bases: ComfortParameter

Parameters of PMV comfort.

Parameters:

• ppd_comfort_thresh – A number between 5 and 100 that represents the upper threshold of PPD that is considered acceptable. Default is 10, which characterizes most buildings in the ASHRAE-55 and EN-15251 standards.

• humid_ratio_upper – A number between 0 and 1 indicating the upper limit of humidity ratio that is considered acceptable. Default is 1 for essentially no limit.

• humid_ratio_lower – A number between 0 and 1 indicating the lower limit of humidity ratio considered acceptable. Default is 0 for essentially no limit.

• still_air_threshold – The air speed threshold in m/s at which the standard effective temperature (SET) model will be used to correct for the cooling effect of elevated air speeds. Default is 0.1 m/s, which is the limit according to ASHRAE-55.

Properties:

• ppd_comfort_thresh

• humid_ratio_upper

• humid_ratio_low

• still_air_threshold

ToString()

Overwrite .NET ToString.

discomfort_reason(pmv, ppd, humidity_ratio=0)

Determine the reason why conditions are comfortable or not.

Values are one of the following:

• -2 = too dry

• -1 = too cold

• 0 = comfortable

• +1 = too hot

• +2 = too humid

duplicate()

Get a copy of this object.

classmethod from_dict(data)

Create a PMVParameter object from a dictionary.

Parameters:

data – A PMVParameter dictionary in following the format below.

{
'type': 'PMVParameter',
'ppd_comfort_thresh': 20,
'humid_ratio_upper': 0.12,
'humid_ratio_lower': 0,
'still_air_threshold': 0.2
}

classmethod from_string(pmv_parameter_string)

Create an PMVParameter object from an PMVParameter string.

is_comfortable(ppd, humidity_ratio=0)

Determine if conditions are comfortable or not.

Values are one of the following:

• 0 = uncomfortable

• 1 = comfortable

set_ppd_comfort_thresh_from_comfort_class(comfort_class)

Set the PPD threshold given the EN-15251 comfort class.

thermal_condition(pmv, ppd)

Determine whether conditions are cold, neutral or hot.

Values are one of the following:

• -1 = cold

• 0 = netural

• +1 = hot

to_dict()

PMVParameter dictionary representation.

property comfort_model

Return the name of the comfort model to which the parameters belong.

property humid_ratio_lower

A number representing the lower boundary of humidity ratio below which conditions are considered too dry to be comfortable. The default is set to 0 kg wather/kg air.

property humid_ratio_upper

A number representing the upper boundary of humidity ratio above which conditions are considered too humid to be comfortable. The default is set to 0.03 kg wather/kg air.

property ppd_comfort_thresh

The threshold of the percentage of people dissatisfied (PPD) beyond which the conditions are not acceptable. The default is 10%.

property still_air_threshold

A number representing the wind speed beyond which the formula for Standard Effective Temperature (SET) is used to determine PMV/PPD (as opposed to Fanger’s original equation). The default is set to 0.1 m/s.