EngineerHub category // Thermal & HVAC
Thermal Engineering & HVAC
Calculate heat transfer, size HVAC equipment, explore psychrometrics, compare cooling systems and study steam, refrigeration and thermal processes.
39 calculator / tools4 interactive simulators9 study materials52 pages total
This collection brings together practical thermal-engineering and HVAC tools for heat and mass transfer, air and water systems, boilers, cooling towers, condensers, refrigeration, humidity control and building climate calculations. Use the calculators for preliminary sizing and checks, then open the simulators and study material when you want to see how the underlying system behaves.
Choose a tool below by purpose. Individual pages include their own assumptions, equations, references and limitations where applicable.
Calculators & tools
39 pages
Data Center Water Usage & WUE CalculatorEstimate data-center cooling-water use, WUE, freshwater demand, tower evaporation, blowdown and discharge from IT load, PUE and cooling architecture.→Bathroom Fan Runtime & Shower Humidity CalculatorEstimate post-shower bathroom humidity, condensation risk and exhaust-fan runtime. Includes delivered airflow guidance and SI/US units.→Battery-Room Hydrogen Ventilation CalculatorEstimate hydrogen generation from stationary aqueous batteries and calculate battery-room exhaust ventilation, air changes, accumulation time, and existing-ventilation concentration.→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 Efficiency / Stack-Loss CalculatorEstimate boiler combustion efficiency from stack temperature, ambient temperature, CO2 percentage and an empirical Siegert fuel factor.→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.→Chiller COP / EER CalculatorConvert between chiller COP, EER and kW/ton, and compute electrical input power or cooling output from any one known efficiency metric.→Condensate Return Savings CalculatorEstimate sensible feedwater-heating energy and fuel-cost savings from returning hot condensate instead of replacing it with cold makeup water.→Condenser Cooling & Circulating Water CalculatorModel condenser cooling in power plants: circulating-water flow, condenser vacuum, heat rejection, cooling-tower performance and turbine backpressure.→Condenser Heat Load & Effectiveness CalculatorCalculate condenser heat load, cooling-water flow, outlet temperature, terminal temperature difference and thermal effectiveness in SI or US units with selectable flow-rate units.→Cooling Coil CalculatorEstimate sensible, latent and total cooling-coil duty from entering/leaving air temperature and humidity ratio using a constant-air-property approximation.→Cooling Tower CalculatorFree cooling tower calculator using Merkel theory. Compare wet, natural-draft, mechanical, hybrid and dry cooling performance, water use and operating cost.→Cooling-Tower Visible-Plume PredictorPredict whether warm, moist cooling-tower exhaust can form a visible condensation plume when mixed with ambient air. Includes a psychrometric mixing plot and SI/US units.→Dehumidifier Sizing CalculatorSize a portable or whole-space dehumidifier using ENERGY STAR room guidance or a psychrometric moisture-load model.→Dew Point CalculatorCalculate dew point temperature from air temperature and relative humidity using the Magnus formula. Includes Celsius and Fahrenheit units.→Fan Laws CalculatorApply the fan affinity laws to estimate corresponding-point flow, pressure and power when speed changes for the same fan and impeller diameter.→Fan Power CalculatorCalculate fan air power, shaft power and electrical input power from airflow rate, pressure rise, and fan and motor efficiency.→Heat Exchanger CalculatorSimulate heat exchanger duty, outlet temperatures, effectiveness, NTU, LMTD, fouling and preliminary shell-and-tube performance in SI or Imperial units.→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.→Heat Exchanger Fouling & Cleaning CalculatorEstimate heat-exchanger fouling resistance, U-value and duty loss, annual energy cost, cleaning payback and net benefit. Includes SI/US units and clear assumptions.→Heating Coil CalculatorCalculate sensible heating coil duty from airflow rate and entering/leaving air temperature, with water or electric coil sizing context.→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.→HVAC Duct Size & Pressure Drop CalculatorA complete duct sizing toolkit with six modes: solve diameter, solve pressure loss, rectangular-to-equivalent-diameter conversion, airflow/velocity, friction rate, and fitting losses.→Pipe Freeze Time & Heat-Trace Sizing ToolEstimate when stagnant water in an insulated pipe may begin to freeze, the idealized full-freeze time, and the heat-trace output needed for freeze protection.→Pipe Insulation Thickness CalculatorEstimate cylindrical pipe insulation thickness needed to meet a target heat loss using conductivity, temperatures and outside heat transfer.→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 Overheating & Solar-Shading CalculatorEstimate room overheating from windows, weather and internal heat. Combine shading, smart ventilation, reduced gains and active cooling.→Simplified Heat Transfer EstimatorEstimate simplified conduction and convection heat transfer using thermal resistance, U-value, area and temperature difference.→Steam Boiler CalculatorCalculate steam boiler heat duty, fuel input, fuel mass flow, feedwater requirement, annual energy use and fuel cost.→Steam Enthalpy CalculatorCalculate water and steam enthalpy, entropy, specific volume and heat capacity using IAPWS-IF97 Regions 1 and 2.→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.→Wet Bulb Temperature CalculatorCalculate wet bulb temperature from dry bulb temperature and relative humidity using the Stull (2011) approximation. Includes evaporative cooling potential, validity checks, HVAC guidance,…→
Interactive simulators
4 pages
Boiling & Critical Heat Flux SimulatorEngineering boiling simulator for nucleate pool boiling, Zuber critical heat flux, CHF margin, heater sizing, flow-boiling energy balance, two-phase flow regimes, boiling number and…→Rankine Cycle Simulator & CalculatorCalculate Rankine cycle efficiency, heat rate, steam quality and power in SI or US units with IAPWS-IF97 properties, reheat, regeneration and live T-s/h-s diagrams.→Refrigeration Cycle SimulatorExplore a reversed-Carnot refrigeration benchmark and an assumed fraction-of-Carnot COP to estimate compressor work and condenser heat rejection from evaporating and condensing temperatures.→Steam Power Cycle SimulatorInteractive steam power cycle simulator: explore boiler pressure, turbine efficiency, condenser backpressure, steam quality, cooling-water flow and T-s states.→
Study materials
9 pages
Dry Cooling Tower (Air-Cooled Condenser)Learn how dry cooling towers (air-cooled condensers) reject heat without evaporation, including heat transfer, efficiency, advantages and limitations.→Heat Transfer Formula SheetHeat transfer formula sheet for conduction, thermal resistance, convection, radiation, overall U-value, LMTD, transient cooling and heat-exchanger effectiveness, with units and worked…→HVAC Formula SheetHVAC formula sheet covering building transmission, sensible and total air heat, humidity ratio, moisture removal, air changes, fan power and COP/EER with ASHRAE-based equations and examples.→Hybrid (Wet/Dry) Cooling TowerLearn how hybrid wet/dry cooling towers reduce visible plume and water consumption by combining dry and evaporative cooling. Free engineering reference from EngineerHub.→Learn HVACA complete educational HVAC guide: how heat moves through buildings, humidity and psychrometrics, dew point, sensible and latent load, ventilation and air changes, and how cooling systems…→Learn Heat TransferConduction, convection and radiation, thermal resistance networks, and heat-exchanger sizing by LMTD and effectiveness–NTU.→Mechanical Forced Draft Cooling TowerLearn how mechanical forced draft cooling towers work, including airflow, heat rejection, fan arrangement, advantages, disadvantages and typical engineering applications.→Mechanical Induced Draft Cooling TowerLearn how mechanical induced draft cooling towers operate, including counterflow cooling, fan placement, heat transfer, performance and engineering applications.→Natural Draft Cooling TowerLearn how natural draft cooling towers work, why hyperbolic shells are used, and where they are applied in nuclear and thermal power plants. Free engineering reference from EngineerHub.→