def calc_m_ve_required(bpr, tsd, region):
"""
Calculate required outdoor air ventilation rate according to occupancy
Author: Legacy
Date: old
:param tsd: Timestep data
:type tsd: Dict[str, numpy.ndarray]
:return: updates tsd
"""
m_ve_required_people = (tsd['ve'] / 3.6) * physics.calc_rho_air(
tsd['T_ext'][:]) * 0.001 # kg/s
if region in {'SG'}:
# 0.6 l/s/m2 minimum ventilation rate according to Singapore standard SS 553
# [https://escholarship.org/content/qt7k1796zv/qt7k1796zv.pdf]
m_ve_required_min = 0.6 * bpr.rc_model['Af'] * physics.calc_rho_air(
tsd['T_ext'][:]) * 0.001 # kg/s
m_ve_required = [
req_min if 0.0 < req_peop < req_min else req_peop for req_min,
req_peop in zip(m_ve_required_min, m_ve_required_people)
]
m_ve_required = np.asarray(m_ve_required) # convert list to array
else:
m_ve_required = m_ve_required_people
tsd['m_ve_required'] = m_ve_required
return
def calc_Eauxf_ve(tsd):
"""
calculation of auxiliary electricity consumption of mechanical ventilation and AC fans
:param tsd: Time series data of building
:type tsd: dict
:return: electrical energy for fans of mechanical ventilation in [Wh/h]
:rtype: float
"""
# TODO: DOCUMENTATION
# FIXME: Why only energy demand for AC? Also other mechanical ventilation should have auxiliary energy demand
# FIXME: What are the units
# m_ve_mech is
fan_power = P_FAN # specific fan consumption in W/m3/h, see globalvar.py
# mechanical ventilation system air flow [m3/s] = outdoor air + recirculation air
q_ve_mech = tsd['m_ve_mech']/physics.calc_rho_air(tsd['theta_ve_mech']) \
+ tsd['m_ve_rec']/physics.calc_rho_air(tsd['T_int'])
Eve_aux = fan_power * q_ve_mech * 3600
tsd['Eaux_ve'] = np.nan_to_num(Eve_aux)
return tsd
def calc_qm_lea(p_zone_ref, temp_zone, temp_ext, u_wind_site,
dict_props_nat_vent):
"""
Calculation of leakage infiltration and exfiltration air mass flow as a function of zone indoor reference pressure
Parameters
----------
p_zone_ref : zone reference pressure (Pa)
temp_zone : air temperature in ventilation zone (°C)
temp_ext : exterior air temperature (°C)
u_wind_site : wind velocity (m/s)
dict_props_nat_vent : dictionary containing natural ventilation properties of zone
Returns
-------
qm_lea_in : air mass flow rate into zone through leakages (kg/h)
qm_lea_out : air mass flow rate out of zone through leakages (kg/h)
"""
# get default leakage paths from locals
coeff_lea_path = dict_props_nat_vent['coeff_lea_path']
height_lea_path = dict_props_nat_vent['height_lea_path']
# lookup wind pressure coefficients for leakage paths from locals
coeff_wind_pressure_path = dict_props_nat_vent[
'coeff_wind_pressure_path_lea']
# calculation of pressure difference at leakage path
delta_p_path = calc_delta_p_path(p_zone_ref, height_lea_path, temp_zone,
coeff_wind_pressure_path, u_wind_site,
temp_ext)
# calculation of leakage air volume flow at path
qv_lea_path = calc_qv_lea_path(coeff_lea_path, delta_p_path)
# Eq. (65) in [1], infiltration is sum of air flows greater zero
qv_lea_in = qv_lea_path[np.where(qv_lea_path > 0)].sum()
# Eq. (66) in [1], exfiltration is sum of air flows smaller zero
qv_lea_out = qv_lea_path[np.where(qv_lea_path < 0)].sum()
# conversion to air mass flows according to 6.4.3.8 in [1]
# Eq. (67) in [1]
qm_lea_in = qv_lea_in * calc_rho_air(temp_ext)
# Eq. (68) in [1]
qm_lea_out = qv_lea_out * calc_rho_air(temp_zone)
# print (qm_lea_in, qm_lea_out)
return qm_lea_in, qm_lea_out
def calc_qm_vent(p_zone_ref, temp_zone, temp_ext, u_wind_site,
dict_props_nat_vent):
"""
Calculation of air flows through ventilation openings in the facade
Parameters
----------
p_zone_ref : zone reference pressure (Pa)
temp_zone : zone air temperature (°C)
temp_ext : exterior air temperature (°C)
u_wind_site : wind velocity (m/s)
dict_props_nat_vent : dictionary containing natural ventilation properties of zone
Returns
-------
qm_vent_in : air mass flow rate into zone through ventilation openings (kg/h)
qm_vent_out : air mass flow rate out of zone through ventilation openings (kg/h)
"""
# get properties from locals()
coeff_vent_path = dict_props_nat_vent['coeff_vent_path']
height_vent_path = dict_props_nat_vent['height_vent_path']
coeff_wind_pressure_path = dict_props_nat_vent[
'coeff_wind_pressure_path_vent']
# calculation of pressure difference at leakage path
delta_p_path = calc_delta_p_path(p_zone_ref, height_vent_path, temp_zone,
coeff_wind_pressure_path, u_wind_site,
temp_ext)
# calculation of leakage air volume flow at path
qv_vent_path = calc_qv_vent_path(coeff_vent_path, delta_p_path)
# Eq. (62) in [1], air flow entering through ventilation openings is sum of air flows greater zero
qv_vent_in = qv_vent_path[np.where(qv_vent_path > 0)].sum()
# Eq. (63) in [1], air flow entering through ventilation openings is sum of air flows smaller zero
qv_vent_out = qv_vent_path[np.where(qv_vent_path < 0)].sum()
# conversion to air mass flows according to 6.4.3.8 in [1]
# Eq. (67) in [1]
qm_vent_in = qv_vent_in * calc_rho_air(temp_ext)
# Eq. (68) in [1]
qm_vent_out = qv_vent_out * calc_rho_air(temp_zone)
# print (qm_lea_in, qm_lea_out)
return qm_vent_in, qm_vent_out
def calc_m_ve_leakage_simple(bpr, tsd):
"""
Calculates mass flow rate of leakage at time step t according to ventilation control options and
building systems properties
Estimation of infiltration air volume flow rate according to Eq. (3) in DIN 1946-6
Author: Gabriel Happle
Date: 01/2017
:param bpr: Building properties row object
:type bpr: cea.demand.thermal_loads.BuildingPropertiesRow
:param tsd: Timestep data
:type tsd: Dict[str, numpy.ndarray]
:return: updates tsd
"""
# 'flat rate' infiltration considered for all buildings
# get properties
n50 = bpr.architecture.n50
area_f = bpr.rc_model['Af']
# estimation of infiltration air volume flow rate according to Eq. (3) in DIN 1946-6
n_inf = 0.5 * n50 * (DELTA_P_DIM / 50)**(
2 / 3) # [air changes per hour] m3/h.m2
infiltration = H_F * area_f * n_inf * 0.000277778 # m3/s
tsd['m_ve_inf'] = infiltration * physics.calc_rho_air(
tsd['T_ext'][:]) # (kg/s)
return
def calc_m_ve_leakage_simple(bpr, tsd, gv):
"""
Calculates mass flow rate of leakage at time step t according to ventilation control options and
building systems properties
Estimation of infiltration air volume flow rate according to Eq. (3) in DIN 1946-6
Author: Gabriel Happle
Date: 01/2017
:param bpr: Building properties row object
:param tsd: Time series data dict
:param gv: globalvars
:return: updates tsd
"""
# 'flat rate' infiltration considered for all buildings
# get properties
n50 = bpr.architecture.n50
area_f = bpr.rc_model['Af']
# estimation of infiltration air volume flow rate according to Eq. (3) in DIN 1946-6
n_inf = 0.5 * n50 * (gv.delta_p_dim/50) ** (2/3) # [air changes per hour] m3/h.m2
infiltration = gv.hf * area_f * n_inf * 0.000277778 # m3/s
tsd['m_ve_inf'] = infiltration * physics.calc_rho_air(tsd['T_ext'][:]) # (kg/s)
return
def calc_qm_lea(p_zone_ref, temp_zone, temp_ext, u_wind_site, dict_props_nat_vent):
"""
Calculation of leakage infiltration and exfiltration air mass flow as a function of zone indoor reference pressure
Parameters
----------
p_zone_ref : zone reference pressure (Pa)
temp_zone : air temperature in ventilation zone (°C)
temp_ext : exterior air temperature (°C)
u_wind_site : wind velocity (m/s)
dict_props_nat_vent : dictionary containing natural ventilation properties of zone
Returns
-------
qm_lea_in : air mass flow rate into zone through leakages (kg/h)
qm_lea_out : air mass flow rate out of zone through leakages (kg/h)
"""
# get default leakage paths from locals
coeff_lea_path = dict_props_nat_vent['coeff_lea_path']
height_lea_path = dict_props_nat_vent['height_lea_path']
# lookup wind pressure coefficients for leakage paths from locals
coeff_wind_pressure_path = dict_props_nat_vent['coeff_wind_pressure_path_lea']
# calculation of pressure difference at leakage path
delta_p_path = calc_delta_p_path(p_zone_ref, height_lea_path, temp_zone, coeff_wind_pressure_path, u_wind_site,
temp_ext)
# calculation of leakage air volume flow at path
qv_lea_path = calc_qv_lea_path(coeff_lea_path, delta_p_path)
# Eq. (65) in [1], infiltration is sum of air flows greater zero
qv_lea_in = qv_lea_path[np.where(qv_lea_path > 0)].sum()
# Eq. (66) in [1], exfiltration is sum of air flows smaller zero
qv_lea_out = qv_lea_path[np.where(qv_lea_path < 0)].sum()
# conversion to air mass flows according to 6.4.3.8 in [1]
# Eq. (67) in [1]
qm_lea_in = qv_lea_in * calc_rho_air(temp_ext)
# Eq. (68) in [1]
qm_lea_out = qv_lea_out * calc_rho_air(temp_zone)
# print (qm_lea_in, qm_lea_out)
return qm_lea_in, qm_lea_out
def calc_qm_vent(p_zone_ref, temp_zone, temp_ext, u_wind_site, dict_props_nat_vent):
"""
Calculation of air flows through ventilation openings in the facade
Parameters
----------
p_zone_ref : zone reference pressure (Pa)
temp_zone : zone air temperature (°C)
temp_ext : exterior air temperature (°C)
u_wind_site : wind velocity (m/s)
dict_props_nat_vent : dictionary containing natural ventilation properties of zone
Returns
-------
qm_vent_in : air mass flow rate into zone through ventilation openings (kg/h)
qm_vent_out : air mass flow rate out of zone through ventilation openings (kg/h)
"""
# get properties from locals()
coeff_vent_path = dict_props_nat_vent['coeff_vent_path']
height_vent_path = dict_props_nat_vent['height_vent_path']
coeff_wind_pressure_path = dict_props_nat_vent['coeff_wind_pressure_path_vent']
# calculation of pressure difference at leakage path
delta_p_path = calc_delta_p_path(p_zone_ref, height_vent_path, temp_zone, coeff_wind_pressure_path, u_wind_site,
temp_ext)
# calculation of leakage air volume flow at path
qv_vent_path = calc_qv_vent_path(coeff_vent_path, delta_p_path)
# Eq. (62) in [1], air flow entering through ventilation openings is sum of air flows greater zero
qv_vent_in = qv_vent_path[np.where(qv_vent_path > 0)].sum()
# Eq. (63) in [1], air flow entering through ventilation openings is sum of air flows smaller zero
qv_vent_out = qv_vent_path[np.where(qv_vent_path < 0)].sum()
# conversion to air mass flows according to 6.4.3.8 in [1]
# Eq. (67) in [1]
qm_vent_in = qv_vent_in * calc_rho_air(temp_ext)
# Eq. (68) in [1]
qm_vent_out = qv_vent_out * calc_rho_air(temp_zone)
# print (qm_lea_in, qm_lea_out)
return qm_vent_in, qm_vent_out
def calc_m_ve_required(bpr, tsd):
"""
Calculate required outdoor air ventilation rate according to occupancy
Author: Legacy
Date: old
:param tsd: Timestep data
:type tsd: Dict[str, numpy.ndarray]
:return: updates tsd
"""
m_ve_required_people = (tsd['ve']/3.6) * physics.calc_rho_air(tsd['T_ext'][:]) * 0.001 # kg/s
if control_heating_cooling_systems.has_3for2_cooling_system(bpr) \
or control_heating_cooling_systems.has_central_ac_cooling_system(bpr):
# 0.6 l/s/m2 minimum ventilation rate according to Singapore standard SS 553
# air conditioning systems supply the higher rate between minimum flow per area and required ventilation for
# people during occupied hours. The minimum flow rate ensures dilution of pollutants inside the building
# This applies to buildings with air-conditioning systems for cooling
# [https://escholarship.org/content/qt7k1796zv/qt7k1796zv.pdf]
m_ve_required_min = constants.MIN_VENTILATION_RATE * bpr.rc_model['Af'] * physics.calc_rho_air(tsd['T_ext'][:]) * 0.001 # kg/s
# we want this not to affect the air flows during the heating season
m_ve_required = []
for t in range(0, HOURS_IN_YEAR):
if 0.0 < m_ve_required_people[t] < m_ve_required_min[t] and \
control_heating_cooling_systems.is_cooling_season(t, bpr):
m_ve_required.append(m_ve_required_min[t])
else:
m_ve_required.append(m_ve_required_people[t])
#m_ve_required = [req_min if 0.0 < req_peop < req_min else req_peop for req_min, req_peop in zip(m_ve_required_min, m_ve_required_people)]
m_ve_required = np.asarray(m_ve_required) # convert list to array
else:
m_ve_required = m_ve_required_people
tsd['m_ve_required'] = m_ve_required
return
def calc_m_ve_required(tsd):
"""
Calculate required outdoor air ventilation rate according to occupancy
Author: Legacy
Date: old
:param tsd: Timestep data
:type tsd: Dict[str, numpy.ndarray]
:return: updates tsd
"""
rho_kgm3 = physics.calc_rho_air(tsd['T_ext'][:])
tsd['m_ve_required'] = np.array(tsd['ve_lps']) * rho_kgm3 * 0.001 # kg/s
return
def calc_m_ve_required(bpr, tsd):
"""
Calculate required outdoor air ventilation rate according to occupancy
Author: Legacy
Date: old
:param bpr: Building properties row object
:param tsd: Time series data dict
:return: updates tsd
"""
tsd['m_ve_required'] = (tsd['ve']/3.6) * physics.calc_rho_air(tsd['T_ext'][:]) * 0.001 # kg/s
return
def calc_qm_arg(factor_cros, temp_ext, dict_windows_building, u_wind_10, temp_zone, r_window_arg):
"""
Calculation of cross ventilated and non-cross ventilated window ventilation according to procedure in 6.4.3.5.4
in [1]
:param factor_cros : cross ventilation factor [0,1]
:param temp_ext : exterior temperature (°C)
:param dict_windows_building : dictionary containing information of all windows in building
:param u_wind_10 : wind velocity (m/s)
:param temp_zone : zone temperature (°C)
:param r_window_arg : fraction of window opening (-)
:returns: window ventilation air mass flows in (kg/h)
"""
# initialize result
q_v_arg_in = 0
q_v_arg_out = 0
qm_arg_in = qm_arg_out = 0 # this is the output for buildings without windows
# if building has windows
if dict_windows_building:
# constants from Table 12 in [1]
# TODO import from global variables
rho_air_ref = 1.23 # (kg/m3)
coeff_turb = 0.01 # (m/s)
coeff_wind = 0.001 # (1/(m/s))
coeff_stack = 0.0035 # ((m/s)/(mK))
# default values from annex B in [1]
coeff_d_window = 0.67 # (-), B.1.2.1 in [1]
delta_c_p = 0.75 # (-), option 2 in B.1.3.4 in [1]
# get necessary inputs
rho_air_ext = calc_rho_air(temp_ext)
rho_air_zone = calc_rho_air(temp_zone)
area_window_tot = calc_area_window_tot(dict_windows_building, r_window_arg)
h_window_stack = calc_effective_stack_height(dict_windows_building)
# print(h_window_stack, area_window_tot)
# volume flow rates of non-cross ventilated zone according to 6.4.3.5.4.2 in [1]
if factor_cros == 0:
# Eq. (47) in [1]
# FIXME: this equation was modified from the version in the standard (possibly wrong in preliminary version)
# TODO: check final edition of standard as soon as possible
q_v_arg_in = 3600 * rho_air_ref / rho_air_ext * area_window_tot / 2 * (
coeff_turb + coeff_wind * u_wind_10 ** 2 + coeff_stack * h_window_stack * abs(
temp_zone - temp_ext)) # ** 0.5
# Eq. (48) in [1]
q_v_arg_out = -3600 * rho_air_ref / rho_air_zone * area_window_tot / 2 * (
coeff_turb + coeff_wind * u_wind_10 ** 2 + coeff_stack * h_window_stack * abs(
temp_zone - temp_ext)) # ** 0.5
# print(coeff_turb + coeff_wind * u_wind_10 ** 2 + coeff_stack * h_window_stack * abs(temp_zone - temp_ext))
elif factor_cros == 1:
# get window area of cross-ventilation
area_window_cros = calc_area_window_cros(dict_windows_building, r_window_arg)
# print(area_window_cros)
# Eq. (49) in [1]
q_v_arg_in = 3600 * rho_air_ref / rho_air_ext * ((
coeff_d_window * area_window_cros * u_wind_10 * delta_c_p ** 0.5) ** 2 + (
area_window_tot / 2 * (
coeff_stack * h_window_stack * abs(
temp_zone - temp_ext))) ** 2) ** 0.5
# Eq. (50) in [1]
# TODO this formula was changed from the standard to use the air density in the zone
# TODO adjusted from the standard to have consistent units
# TODO check final edition of standard as soon as possible
q_v_arg_out = -3600 * rho_air_ref / rho_air_zone * ((
coeff_d_window * area_window_cros * u_wind_10 * delta_c_p ** 0.5) ** 2 + (
area_window_tot / 2 * (
coeff_stack * h_window_stack * abs(
temp_zone - temp_ext))) ** 2) ** 0.5
# conversion to air mass flows according to 6.4.3.8 in [1]
# Eq. (67) in [1]
qm_arg_in = q_v_arg_in * calc_rho_air(temp_ext)
# Eq. (68) in [1]
qm_arg_out = q_v_arg_out * calc_rho_air(temp_zone)
return qm_arg_in, qm_arg_out
def calc_qm_arg(factor_cros, temp_ext, dict_windows_building, u_wind_10, temp_zone, r_window_arg):
"""
Calculation of cross ventilated and non-cross ventilated window ventilation according to procedure in 6.4.3.5.4
in [1]
Parameters
----------
factor_cros : cross ventilation factor [0,1]
temp_ext : exterior temperature (°C)
dict_windows_building : dictionary containing information of all windows in building
u_wind_10 : wind velocity (m/s)
temp_zone : zone temperature (°C)
r_window_arg : fraction of window opening (-)
Returns
-------
window ventilation air mass flows in (kg/h)
"""
# initialize result
q_v_arg_in = 0
q_v_arg_out = 0
qm_arg_in = qm_arg_out = 0 # this is the output for buildings without windows
# if building has windows
if dict_windows_building:
# constants from Table 12 in [1]
# TODO import from global variables
rho_air_ref = 1.23 # (kg/m3)
coeff_turb = 0.01 # (m/s)
coeff_wind = 0.001 # (1/(m/s))
coeff_stack = 0.0035 # ((m/s)/(mK))
# default values from annex B in [1]
coeff_d_window = 0.67 # (-), B.1.2.1 in [1]
delta_c_p = 0.75 # (-), option 2 in B.1.3.4 in [1]
# get necessary inputs
rho_air_ext = calc_rho_air(temp_ext)
rho_air_zone = calc_rho_air(temp_zone)
area_window_tot = calc_area_window_tot(dict_windows_building, r_window_arg)
h_window_stack = calc_effective_stack_height(dict_windows_building)
# print(h_window_stack, area_window_tot)
# volume flow rates of non-cross ventilated zone according to 6.4.3.5.4.2 in [1]
if factor_cros == 0:
# Eq. (47) in [1]
# FIXME: this equation was modified from the version in the standard (possibly wrong in preliminary version)
# TODO: check final edition of standard as soon as possible
q_v_arg_in = 3600 * rho_air_ref / rho_air_ext * area_window_tot / 2 * (
coeff_turb + coeff_wind * u_wind_10 ** 2 + coeff_stack * h_window_stack * abs(
temp_zone - temp_ext)) # ** 0.5
# Eq. (48) in [1]
q_v_arg_out = -3600 * rho_air_ref / rho_air_zone * area_window_tot / 2 * (
coeff_turb + coeff_wind * u_wind_10 ** 2 + coeff_stack * h_window_stack * abs(
temp_zone - temp_ext)) # ** 0.5
# print(coeff_turb + coeff_wind * u_wind_10 ** 2 + coeff_stack * h_window_stack * abs(temp_zone - temp_ext))
elif factor_cros == 1:
# get window area of cross-ventilation
area_window_cros = calc_area_window_cros(dict_windows_building, r_window_arg)
# print(area_window_cros)
# Eq. (49) in [1]
q_v_arg_in = 3600 * rho_air_ref / rho_air_ext * ((
coeff_d_window * area_window_cros * u_wind_10 * delta_c_p ** 0.5) ** 2 + (
area_window_tot / 2 * (
coeff_stack * h_window_stack * abs(
temp_zone - temp_ext))) ** 2) ** 0.5
# Eq. (50) in [1]
# TODO this formula was changed from the standard to use the air density in the zone
# TODO adjusted from the standard to have consistent units
# TODO check final edition of standard as soon as possible
q_v_arg_out = -3600 * rho_air_ref / rho_air_zone * ((
coeff_d_window * area_window_cros * u_wind_10 * delta_c_p ** 0.5) ** 2 + (
area_window_tot / 2 * (
coeff_stack * h_window_stack * abs(
temp_zone - temp_ext))) ** 2) ** 0.5
# conversion to air mass flows according to 6.4.3.8 in [1]
# Eq. (67) in [1]
qm_arg_in = q_v_arg_in * calc_rho_air(temp_ext)
# Eq. (68) in [1]
qm_arg_out = q_v_arg_out * calc_rho_air(temp_zone)
return qm_arg_in, qm_arg_out
