{ "status": "ENGINEERING_ARITHMETIC_NOT_HARDWARE_VALIDATION", "generated_by": "compact-hardware-calculations.py", "constants": { "rho_kg_m3": 1.18, "cp_J_kg_K": 1005.0, "CFM_to_m3_s": 0.00047194745, "mm_H2O_to_Pa": 9.80665 }, "minimum_bulk_airflow": [ { "power_to_air_W": 8, "bulk_air_rise_K": 8, "minimum_CFM": 1.786727, "minimum_m3_h": 3.035669 }, { "power_to_air_W": 8, "bulk_air_rise_K": 12, "minimum_CFM": 1.191152, "minimum_m3_h": 2.023779 }, { "power_to_air_W": 8, "bulk_air_rise_K": 15, "minimum_CFM": 0.952921, "minimum_m3_h": 1.619024 }, { "power_to_air_W": 12, "bulk_air_rise_K": 8, "minimum_CFM": 2.680091, "minimum_m3_h": 4.553504 }, { "power_to_air_W": 12, "bulk_air_rise_K": 12, "minimum_CFM": 1.786727, "minimum_m3_h": 3.035669 }, { "power_to_air_W": 12, "bulk_air_rise_K": 15, "minimum_CFM": 1.429382, "minimum_m3_h": 2.428535 }, { "power_to_air_W": 18, "bulk_air_rise_K": 8, "minimum_CFM": 4.020137, "minimum_m3_h": 6.830256 }, { "power_to_air_W": 18, "bulk_air_rise_K": 12, "minimum_CFM": 2.680091, "minimum_m3_h": 4.553504 }, { "power_to_air_W": 18, "bulk_air_rise_K": 15, "minimum_CFM": 2.144073, "minimum_m3_h": 3.642803 }, { "power_to_air_W": 25, "bulk_air_rise_K": 8, "minimum_CFM": 5.583523, "minimum_m3_h": 9.486466 }, { "power_to_air_W": 25, "bulk_air_rise_K": 12, "minimum_CFM": 3.722349, "minimum_m3_h": 6.324311 }, { "power_to_air_W": 25, "bulk_air_rise_K": 15, "minimum_CFM": 2.977879, "minimum_m3_h": 5.059449 }, { "power_to_air_W": 30, "bulk_air_rise_K": 8, "minimum_CFM": 6.700228, "minimum_m3_h": 11.383759 }, { "power_to_air_W": 30, "bulk_air_rise_K": 12, "minimum_CFM": 4.466818, "minimum_m3_h": 7.589173 }, { "power_to_air_W": 30, "bulk_air_rise_K": 15, "minimum_CFM": 3.573455, "minimum_m3_h": 6.071338 } ], "bypass_sensitivity": [ { "power_W": 18, "delta_air_K": 12, "assumed_useful_fraction": 0.6, "useful_CFM": 2.680091, "fan_CFM_if_only_60_percent_reaches_hot_path": 4.466818 }, { "power_W": 25, "delta_air_K": 12, "assumed_useful_fraction": 0.6, "useful_CFM": 3.722349, "fan_CFM_if_only_60_percent_reaches_hot_path": 6.203914 } ], "pad_example_not_total_thermal_resistance": [ { "thickness_mm": 0.5, "conductivity_W_mK": 3, "assumed_contact_area_mm2": 400, "pad_R_K_W": 0.416667, "pad_drop_at_10W_K": 4.166667 }, { "thickness_mm": 1.5, "conductivity_W_mK": 3, "assumed_contact_area_mm2": 400, "pad_R_K_W": 1.25, "pad_drop_at_10W_K": 12.5 } ], "junction_path_budget_example": { "ambient_C": 35, "local_air_rise_K_assumed": 12, "junction_project_target_C": 75, "SoC_power_W_assumed": 10, "max_effective_junction_to_local_air_K_W": 2.8, "warning": "Not datasheet thetaJA; package/TIM/spreading/heatsink all contribute. Verify in actual assembly." }, "filter_face_velocity_at_3CFM": [ { "two_equal_filters_each_side_mm": 40, "gross_total_area_m2": 0.0032, "gross_face_velocity_m_s": 0.442451 }, { "two_equal_filters_each_side_mm": 60, "gross_total_area_m2": 0.0072, "gross_face_velocity_m_s": 0.196645 } ], "bottom_gap_gross_entry_area": [ { "case_side_mm": 90, "gap_mm": 3, "four_sides_area_mm2": 1080, "ratio_to_40mm_fan_square": 0.675, "warning": "Upper geometric estimate; feet, furniture and grilles reduce open area." }, { "case_side_mm": 90, "gap_mm": 8, "four_sides_area_mm2": 2880, "ratio_to_40mm_fan_square": 1.8, "warning": "Upper geometric estimate; feet, furniture and grilles reduce open area." }, { "case_side_mm": 90, "gap_mm": 12, "four_sides_area_mm2": 4320, "ratio_to_40mm_fan_square": 2.7, "warning": "Upper geometric estimate; feet, furniture and grilles reduce open area." } ], "independent_equal_fan_acoustic_addition_same_RPM": [ { "count": 1, "added_dB": 0.0 }, { "count": 2, "added_dB": 3.0103 }, { "count": 3, "added_dB": 4.771213 } ], "fan_catalog_conversions": { "Noctua_NF_A4x10_5V_PWM": { "free_air_m3_h": 8.9, "free_air_CFM": 5.24, "zero_flow_mmH2O": 1.95, "zero_flow_Pa": 19.122967, "three_max_input_W_excludes_controller": 1.05 }, "Noctua_NF_A4x20_5V_PWM": { "free_air_m3_h": 9.4, "free_air_CFM": 5.53, "zero_flow_mmH2O": 2.26, "zero_flow_Pa": 22.163029 }, "Delta_EFB0405HA": { "free_air_CFM": 6.92, "zero_flow_mmH2O": 3.28, "zero_flow_Pa": 32.165812 } }, "cube_volume_L": { "57": 0.185193, "90": 0.729, "105": 1.157625, "120": 1.728, "324": 34.012224 }, "hypothetical_three_port_network": { "status": "TEACHING_MODEL_ONLY_NOT_A_PRODUCT_FAN_CURVE_OR_PREDICTED_CASE_PERFORMANCE", "fan_curve": "p_f(Q) = 20 - 4*Q, pressure Pa, flow CFM, only 0<=Q<=5", "system_curve": "Each branch pressure loss K*Q*abs(Q); no leakage/turn interaction/reverse active-fan flow", "one_top_fan_two_passive_inlets": { "case_pressure_Pa": -2.28849, "bottom_CFM": 1.069694, "left_CFM_signed": 1.069694, "top_exhaust_CFM": 2.139388, "K_bottom_Pa_per_CFM2": 2.0, "K_left_Pa_per_CFM2": 2.0, "K_outlet_Pa_per_CFM2": 2.0 }, "bottom_and_top_fans_left_passive": { "case_pressure_Pa": -0.0, "bottom_CFM": 2.316625, "left_CFM_signed": 0.0, "top_exhaust_CFM": 2.316625, "K_bottom_Pa_per_CFM2": 2.0, "K_left_Pa_per_CFM2": 2.0, "K_outlet_Pa_per_CFM2": 2.0 }, "bottom_left_intake_and_top_exhaust": { "case_pressure_Pa": 9.619102, "bottom_CFM": 1.488061, "left_CFM_signed": 1.488061, "top_exhaust_CFM": 2.976123, "K_bottom_Pa_per_CFM2": 2.0, "K_left_Pa_per_CFM2": 2.0, "K_outlet_Pa_per_CFM2": 2.0 }, "two_fans_more_restrictive_top_can_reverse_left_port": { "case_pressure_Pa": 0.438617, "bottom_CFM": 2.283396, "left_CFM_signed": -0.468304, "top_exhaust_CFM": 1.815093, "K_bottom_Pa_per_CFM2": 2.0, "K_left_Pa_per_CFM2": 2.0, "K_outlet_Pa_per_CFM2": 4 }, "warning": "Do not select a fan or enclosure size from these invented numerical operating points." } }