EngineerHub category // Building Energy
Building Energy & Services
Estimate building heat loss, HVAC and ventilation needs, lighting, hot water, humidity risk and envelope performance for preliminary building-services work.
23 calculator / tools1 interactive simulator24 pages total
The building-energy collection is aimed at building physics and building-services questions: envelope heat transfer, heating and cooling loads, ventilation, humidity, emitters, hot water and lighting. It overlaps intentionally with HVAC and household tools, but this page keeps the building as the system boundary and groups the tools most useful for whole-room or whole-building decisions.
Choose a tool below by purpose. Individual pages include their own assumptions, equations, references and limitations where applicable.
Calculators & tools
23 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.→Boiler Size Calculator for Homes & BuildingsEstimate boiler capacity from floor area or a detailed building-envelope and ventilation heat-loss calculation, including combi hot-water demand.→Building Heat Loss CalculatorTwo-mode building heat-loss calculator: a fast screening estimate and a detailed component method with wall, window, door, roof, floor and infiltration breakdown.→Cooling Coil CalculatorEstimate sensible, latent and total cooling-coil duty from entering/leaving air temperature and humidity ratio using a constant-air-property approximation.→Dehumidifier Sizing CalculatorSize a portable or whole-space dehumidifier using ENERGY STAR room guidance or a psychrometric moisture-load model.→Heat Recovery Effectiveness CalculatorCalculate sensible effectiveness of an air-to-air heat recovery ventilator from supply and exhaust airstream temperatures, plus recovered heat and energy savings.→Heating Coil CalculatorCalculate sensible heating coil duty from airflow rate and entering/leaving air temperature, with water or electric coil sizing context.→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.→Humidification CalculatorEstimate water addition rate and minimum thermal steam-generation load required to raise air humidity ratio from entering to target conditions.→HVAC BTU Load CalculatorEstimate heating and cooling capacity in BTU/h, kW and tons with basic room sizing or an advanced envelope, ventilation, solar and internal-gain model.→Insulation / U-Value / R-Value CalculatorBuild a layered wall, roof or floor visually and calculate U-value, SI/US R-value, heat loss, inside surface temperature, dew point and added insulation needed.→Psychrometric Calculator & Interactive ChartDetailed ASHRAE-based psychrometric calculator and interactive chart for dry-bulb, wet-bulb, dew point, RH, humidity ratio, enthalpy, specific volume, vapor pressure and altitude effects.→Radiator Balancing WizardCalculate required flow rate and balancing valve Kv setting for up to 6 radiators from heat output, system temperature drop and available pressure at each valve.→Radiator Sizing CalculatorSize a radiator from room heat loss and water temperatures. Estimate ΔT50 catalogue rating, correction factor and hydronic flow in SI or US units.→Room Lighting Lux Layout & Reflectance CalculatorEstimate luminaire count and a regular room layout with the lumen method using room index, a manufacturer-provided utilization factor, maintenance factor and luminaire spacing-to-height…→Room Overheating & Solar-Shading CalculatorEstimate room overheating from windows, weather and internal heat. Combine shading, smart ventilation, reduced gains and active cooling.→Thermal Storage Sizing CalculatorSize ice or chilled-water thermal storage from a target cooling load and duration, comparing required mass, volume and tank size for each storage medium.→Ventilation, Airflow & ACH CalculatorCalculate room airflow, CFM, m3/h, air changes per hour and ideal airing time. Compare ventilation with room volume, occupants and a removal target.→Wall Heat Transfer CalculatorCalculate steady-state wall heat transfer, U-value, thermal resistance, heat flux, surface temperatures and layer-by-layer temperature drops. Supports SI and US customary units.→Water Heater / Hot-Water Sizing CalculatorSize storage or tankless water heating from peak-hour demand, tank temperature, recovery power, temperature rise and simultaneous flow.→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.→
Interactive simulators
1 page