EngineerHub category // Household Tools
Household Engineering Tools
Use engineering methods for practical home decisions—from heating, solar and EV charging to backup power, ventilation, humidity and condensation risk.
14 calculator / tools1 interactive simulator16 pages total
Household tools translate engineering calculations into practical home decisions while keeping the assumptions visible. The collection covers energy use, heating, solar and storage, EV charging, backup power, ventilation, indoor humidity and resilience. Results are intended for screening and comparison; electrical, structural and code-sensitive work should still be checked by a qualified professional.
Choose a tool below by purpose. Individual pages include their own assumptions, equations, references and limitations where applicable.
Calculators & tools
14 pages
Air Purifier CADR CalculatorCalculate required air purifier CADR from room dimensions and target clean-air changes. Compare EPA room-size guidance and candidate purifier capacity.→Bathroom Fan Runtime & Shower Humidity CalculatorEstimate post-shower bathroom humidity, condensation risk and exhaust-fan runtime. Includes delivered airflow guidance and SI/US units.→Bedroom CO₂, Humidity & Ventilation CalculatorEstimate overnight bedroom CO2, humidity and condensation risk from room size, sleepers and ventilation. See wake-up levels and required outdoor airflow.→EV Charging Schedule & Tariff CalculatorCreate a low-cost EV charging schedule using departure time, electricity tariff, solar, household demand and home main-fuse headroom.→Fridge and Freezer Power-Outage PlannerTwo-mode planner: USDA/FSIS outage reference guidance for refrigerators/freezers plus a conservative backup-power sizing estimate from appliance running and starting watts.→Generator Sizing ToolEstimate home generator size from monthly electricity use or appliance running and starting watts. Includes surge checks, safety guidance and examples.→Home Battery Storage Sizing CalculatorEstimate home battery capacity, backup runtime and inverter power from monthly electricity use or a detailed appliance list.→Home Battery Payback & Solar Self-Consumption CalculatorEstimate battery payback, solar self-consumption, TOU arbitrage and the marginal value of adding another battery module.→Home Heat Pump Size & Running Cost CalculatorEstimate air-source or ground-source heat-pump size, design heat loss, cold-weather output, annual electricity use and home heating cost in SI or US units.→Home Main Fuse & EV Charger CalculatorCheck whether an EV charger, heat pump, sauna and other loads fit your home electrical service. Supports European 230/400 V, UK and North American 120/240 V systems.→Home Solar Panel Size CalculatorEstimate how many solar panels your home needs from electricity use, roof space and region. Compare monthly output, annual savings and payback.→Sump Pump and Backup Runtime CalculatorCalculate sump pump cycle time, duty cycle and short-cycling risk from basin geometry and flow rates, then estimate battery backup runtime during a power outage.→Well Pump Backup Runtime & Recovery CalculatorCalculate pressure tank drawdown using Boyle's Law, well pump cycle time, and battery backup runtime for household water usage during a power outage.→Window Condensation & Mould-Risk CalculatorCheck whether a measured cold window, frame or wall will condense. Calculate dew point, surface humidity and practical moisture-control actions.→
Worked examples
1 page
Interactive simulators
1 page