Allday HVAC Calc

Dmitrii Pankov

About this app

The application can be useful for HVAC engineers and contains 3 modules.

Psychrometric Calculator - this module determines air properties based on input values such as dry-bulb temperature, wet-bulb temperature, and relative humidity. It provides results like humidity ratio, specific volume, enthalpy, and vapor pressure in both SI and IP units.

Pipe Calculator - this module is used to calculate velocity and pressure loss in pipelines and to select pipeline diameters for a given maximum velocity and pressure loss. The module supports interdependent calculations of flow rate, heat load, and fluid temperatures: when any three of these parameters are specified, the fourth is calculated automatically. It can also be used as a reference for heat transfer fluid properties and pipe characteristics.

Duct Calculator - the module is used to calculate the speed and pressure loss in round, rectangular and oval air ducts when moving wet or dry air through them, as well as to select their sections for a given maximum speed and maximum pressure loss. Additionally, the heating or cooling power is calculated for a given air flow rate, or reverse calculations: air flow rate for a given power; temperature of incoming or outgoing air for a given power and flow rate. It can also be used as a reference material for determining the properties of wet and dry air at different pressures and temperatures.

Also in the description sections are the reference formulas by which the calculations are made.

Web version: calc.ashrae-meteo.info

What’s new

In the "Calculate Flow from Known Power" section of the Pipe module, added the ability to calculate Power (Q) based on flow rate, as well as Inlet/Outlet temperatures (Tin/Tout) based on Q and flow rate.

App-wide improvements include higher precision, smarter unit conversion, and dynamic recalculations, along with UI enhancements for a smoother experience. Overall, this version delivers better accuracy, improved performance, and important bug fixes for increased stability.