Calculator catalog
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Found 37 calculators
Air flow from air changes per hour
Calculates air flow from air changes per hour and room volume.
ACH from air flow
Calculates air changes per hour from air flow and room volume.
Fan power from flow and pressure rise
Calculates auxiliary fan power from volumetric flow rate, pressure rise, and efficiency.
Simple absolute humidity
Calculates auxiliary absolute humidity from water vapor pressure and temperature without climate tables.
Air heating power from flow and delta T
Estimates air heating power from volumetric flow rate and temperature difference.
Water heating power from flow and delta T
Estimates water heating power from volumetric flow rate and temperature difference.
Ventilation heat loss
Calculates a helper sensible heat-loss estimate for an air stream from density, specific heat, flow rate and temperature difference.
Humid air enthalpy
Calculates a helper simplified humid-air enthalpy from dry-bulb temperature and humidity ratio.
Air cooling power from flow and delta T
Estimates sensible air cooling power from volumetric flow rate and temperature difference.
Magnus dew point
Calculates a helper dew-point estimate for humid air from temperature and relative humidity; it does not replace HVAC condition validation.
Humidity ratio from temperature and RH
Calculates humidity ratio from temperature, relative humidity, and atmospheric pressure using the Magnus approximation.
Stull wet-bulb temperature
Estimates wet-bulb temperature with the empirical Stull equation over its limited temperature and RH range.
Two-stream moist-air mixing
Mixes two dry-air streams by humidity-ratio and moist-air enthalpy balances.
Cooling water flow rate from power
Calculates cooling-water volumetric flow from power, density, specific heat, and temperature difference.
Total cooling load from sensible and latent load
Sums sensible and latent cooling load without automatic equipment sizing.
Condensate rate from humidity-ratio difference
Calculates condensate mass flow from dry-air mass flow and humidity-ratio decrease.
Cooling energy from power and time
Calculates cooling energy from cooling power and time using the same relation as the thermal calculator.
Wall heat loss from U-value
Estimates heat loss through a wall from U-value, area, and temperature difference.
Required flat insulation thickness
Calculates required flat insulation thickness from conductivity, area, temperature difference, and allowed heat loss.
Pipe insulation heat loss
Calculates heat loss through a cylindrical pipe insulation layer using a simplified radial-conduction model.
Wall internal surface temperature
Calculates internal surface temperature from indoor temperature, heat flux, and internal surface resistance.
Condensation temperature margin
Calculates the difference between surface temperature and dew-point temperature without automatic building-compliance assessment.
Heat-loss energy through partition
Calculates heat-loss energy through a partition from U-value, area, temperature difference, and time.
Duct air velocity
Calculates duct air velocity from volumetric flow rate and cross-sectional area.
Duct area from flow and velocity
Calculates duct cross-sectional area from volumetric flow rate and air velocity.
Rectangular duct equivalent diameter
Calculates a helper equivalent diameter for a rectangular duct from its side lengths, without HVAC equipment selection.
Room volume
Calculates room volume from length, width, and height.
Room air change time
Calculates one air-change time from room volume and air flow.
Occupancy ventilation flow
Calculates air flow from occupant count and flow per person.
Room heat load from area
Estimates room heat load from floor area and a user-provided load index.
Room cooling load from area
Estimates room cooling load from floor area and a user-provided load index.
Room occupant sensible heat
Calculates occupant sensible heat from occupant count and sensible heat per person.
Room occupant latent heat
Calculates occupant latent heat from occupant count and latent heat per person.
Room total internal heat gain
Sums heat gains from occupants, lighting, and equipment.
Full psychrometrics
Moist-air properties with the Buck equation: RH, W, dew point, wet bulb, vapor pressure, enthalpy, density, comparison and air-stream mixing.
Interactive psychrometric chart
Tdb-W chart with saturation boundary, RH curves, enthalpy and specific-volume lines, state points and HVAC processes.
Sanitary system design
Two pipe-sizing modules: pressurized Hazen-Williams and gravity Manning with velocity, loss and utilization checks.