Equipment Electricity Cost
Estimate electricity use from input power, equipment count and operating time. Apply your energy rate and a separately entered monthly charge.
Use equipment electricity cost →CALCULATORS BY INDUSTRY
HVAC calculators
Work through heat, airflow, efficiency and operating-energy comparisons.
20 free tools. No signup. Methods, examples and source links on every page.
Power Conversion
Convert a known power value between watts (W), kilowatts (kW), mechanical horsepower (hp) and Btu IT per hour. Calculating electrical power from volts and amps is a different task that may also need power factor and phase details.
Use power conversion →Water Flow Unit Conversion
Convert a steady volumetric flow between liters per minute, liters per second, cubic meters per hour and U.S. gallons per minute.
Use water flow unit conversion →Fuel Cost per Input Energy
Turn your fuel unit price and heat content into input-energy cost, including a separate delivered-purchase perspective.
Use fuel cost per input energy →Useful Heating Cost
Use an entered output/input efficiency and matching fuel heat content to estimate metered fuel use and annual operating cost.
Use useful heating cost →Heat Pump vs Boiler Cost
Hold useful heat constant, apply an entered seasonal COP and boiler efficiency, then compare rounded energy and fixed operating costs.
Use heat pump vs boiler cost →Boiler Efficiency Cost Scenario
Compare two output/input boiler efficiencies against the same useful-heat requirement and fuel-energy price.
Use boiler efficiency cost scenario →Cooling Energy Cost
Convert entered useful cooling energy through a matching COP or EER convention to an electrical-energy cost.
Use cooling energy cost →Natural Gas Volume to Energy
Apply a supplied gas billing-volume factor and heating value, with explicit energy-unit conventions.
Use natural gas volume to energy →Cooling Efficiency Unit Converter
Convert equivalent steady-state COP, EER and electrical kW per refrigeration ton on the same rating basis.
Use cooling efficiency unit converter →Cooling Tower Concentration Ratios
Conductivity cycles = circulating conductivity ÷ makeup conductivity.
Use cooling tower concentration ratios →Cooling Tower Water Balance
Accounted makeup requirement is the sum of evaporation, blowdown, drift, leakage and overflow during one common period.
Use cooling tower water balance →Fan Affinity Law Scenario
Let r be new speed divided by positive reference speed.
Use fan affinity law scenario →Fan Air Power
Air power in kW = actual cubic metres per second × pressure rise in Pa ÷ 1,000.
Use fan air power →Heat Exchanger Thermal Duty
Signed heat removed in kW = mass flow in kg/s × enthalpy drop in kJ/kg.
Use heat exchanger thermal duty →Heat Exchanger LMTD
Counterflow terminal approaches are hot-in minus cold-out and hot-out minus cold-in.
Use heat exchanger lmtd →Heat Exchanger UA Scenario
Effective UA in kW/K = entered thermal duty in kW ÷ (applicable correction factor × reviewed LMTD in K).
Use heat exchanger ua scenario →Measured Heat Pump COP
Coefficient of performance is useful heating or cooling output divided by electrical input on matching energy and time boundaries.
Use measured heat pump cop →Pump Affinity Law Scenario
For an ideal fixed-geometry centrifugal-pump similarity scenario, r = new speed / reference speed.
Use pump affinity law scenario →Planar Thermal Conduction
Area-normalized resistance in m²·K/W is the sum of each layer’s thickness in metres divided by conductivity in W/(m·K).
Use planar thermal conduction →Before you use these calculations
Use the system boundary and units stated on the page.
Enter suitable measured flows, temperatures and seasonal efficiencies.
Sizing, comfort, ventilation compliance and refrigerant selection require separate review.
Start with the example, replace the assumptions with your measurements, then change one input to see its effect. Save or export the scenario if you need to keep its basis.
How Case calculators are built and checked →Read practical calculation guides or browse another industry.