enex_analysis.cop

Heat pump Coefficient of Performance (COP) models.

Provides empirical COP correlations for: - Air source heat pumps (cooling and heating modes) - Ground source heat pumps (modified Carnot model)

Functions

calc_ASHP_cooling_COP(T_a_int_out, ...)

Calculate the Coefficient of Performance (COP) for an Air Source Heat Pump (ASHP) in cooling mode.

calc_ASHP_heating_COP(T0, Q_r_int, Q_r_max)

Calculate the Coefficient of Performance (COP) for an Air Source Heat Pump (ASHP) in heating mode.

calc_GSHP_COP(T_a_iu_in_K, T_f_out_K, ...)

Calculate COP for a Ground Source Heat Pump using the EnergyPlus Coil:*:WaterToAir:EquationFit model (Equation-Fit Method).
enex_analysis.cop.calc_ASHP_cooling_COP(T_a_int_out, T_a_ext_in, Q_r_int, Q_r_max, COP_ref)[source]

Calculate the Coefficient of Performance (COP) for an Air Source Heat Pump (ASHP) in cooling mode.

Reference: https://publications.ibpsa.org/proceedings/bs/2023/papers/bs2023_1118.pdf

Parameters:

  • T_a_int_out (float) – Indoor air temperature [K]

  • T_a_ext_in (float) – Outdoor air temperature [K]

  • Q_r_int (float) – Indoor heat load [W]

  • Q_r_max (float) – Maximum cooling capacity [W]

  • COP_ref (float) – Reference COP at standard conditions

Returns:

COP value

Return type:

float

Note

COP is calculated based on: - PLR: Part Load Ratio - EIR: Energy input to cooling output ratio

enex_analysis.cop.calc_ASHP_heating_COP(T0, Q_r_int, Q_r_max)[source]

Calculate the Coefficient of Performance (COP) for an Air Source Heat Pump (ASHP) in heating mode.

Reference: https://www.mdpi.com/2071-1050/15/3/1880

Parameters:

  • T0 (float) – Environmental temperature [K]

  • Q_r_int (float) – Indoor heat load [W]

  • Q_r_max (float) – Maximum heating capacity [W]

Returns:

COP value

Return type:

float

Note

COP is calculated based on PLR (Part Load Ratio).

enex_analysis.cop.calc_GSHP_COP(T_a_iu_in_K, T_f_out_K, dV_a_ratio, mode)[source]

Calculate COP for a Ground Source Heat Pump using the EnergyPlus Coil:*:WaterToAir:EquationFit model (Equation-Fit Method).

Reference:

EnergyPlus Engineering Reference, Ch.16.5.10.2 (Eq. 16.412-16.418, Tang 2005) Dataset: TCH072_GLHP (ClimateMaster 6-ton, Ground Loop HP) Source: EnergyPlus/datasets/WaterToAirHeatPumps.idf

Rated conditions (from IDF comment, 15% methanol antifreeze):

Cooling: 70.29 kBtu/h @ 77°F (25°C) entering water, EER=14.35 Heating: 56.14 kBtu/h @ 32°F (0°C) entering water, COP=3.42

Parameters:

  • T_a_iu_in_K (float) – Indoor air inlet dry-bulb temperature [K] (= T_a_room). For cooling, internally converted to wet-bulb (T_wb) via CoolProp assuming RH = 50%.

  • T_f_out_K (float) –

    Source-side inlet water temperature [K] = T_f_out (water returning from borehole TO the heat pump,

    i.e., T_w,in in EnergyPlus notation).

  • dV_a_ratio (float) – Load-side air volumetric flow ratio: V_a / V_a_ref [-] V_a_ref = Q_rated / (rho_a * c_a * 10K) [m³/s]

  • mode (str) – “cooling” or “heating”

  • Units

  • -----

  • Temperatures (K)

  • rates (Flow)

  • Heat/Power (W)

Returns:

COP (dimensionless). Polynomial model is unconditionally stable— no ValueError on temperature inversion.

Return type:

float