Facilities HVAC VAV Box Reheat Energy Waste Rate Diagnostic Calculator

Quick Answer

Calculate Facilities HVAC VAV Box Reheat Energy Waste Rate Diagnostic

Result Interpretation

Facilities HVAC VAV Box Reheat Energy Waste Rate Diagnostic Calculator computes Reheat energy waste rate in kW using the defined engineering formula and the input values provided.

Worked Example

Verified calculation

Given:

Zone air specific enthalpy = 46.7
Return air specific enthalpy = 49.1
Supply air specific enthalpy = 28.3
Supply air mass flow rate = 0.45

Expected Result:

Reheat energy waste rate = -9.36

Engineering Interpretation:

Under the given input conditions, the calculated result is: Reheat energy waste rate = -9.36 kW.

The actual numerical result is computed by the Runtime engine using the persisted tool definition. The values shown here come from automatically validated test cases.

Formula / Method

reheat energy waste rate = supply air mass flow rate * (supply air specific enthalpy - zone air specific enthalpy) - supply air mass flow rate * (return air specific enthalpy - zone air specific enthalpy)

Formula family: formula_facilities_facilities_hvac_reheat_energy_waste_diagnostic

Variables

Symbol	Label	Role	Description
m_dot_air	Supply air mass flow rate	INPUT	Supply air mass flow rate
h_supply	Supply air specific enthalpy	INPUT	Supply air specific enthalpy
h_return	Return air specific enthalpy	INPUT	Return air specific enthalpy
h_zone	Zone air specific enthalpy	INPUT	Zone air specific enthalpy
reheat_energy_waste_rate	Reheat energy waste rate	OUTPUT	Reheat energy waste rate

Calculation Steps

Enter the supply air mass flow rate in kg/s.
Enter the supply air specific enthalpy in kJ/kg.
Enter the return air specific enthalpy in kJ/kg.
Enter the zone air specific enthalpy in kJ/kg.
Step 1: Compute reheat energy waste rate.
Read the reheat energy waste rate (kW) from the results.

Engineering Summary

Calculate Facilities HVAC VAV Box Reheat Energy Waste Rate Diagnostic

Frequently Asked Questions

What does this calculator calculate?

The Facilities HVAC VAV Box Reheat Energy Waste Rate Diagnostic Calculator estimates Reheat energy waste rate based on the input parameters you provide

Why is supply air mass flow rate important in this calculation?

supply air mass flow rate is directly proportional to reheat energy waste rate. When you enter supply air mass flow rate in kg/s, the calculator uses it in the engineering formula to compute the output

How should I interpret the result reheat energy waste rate?

The calculator outputs reheat energy waste rate in kW. The result is computed directly from the input values using the defined engineering formula

What units should I use for the inputs?

Enter each value in the units shown next to the input field: Supply air mass flow rate (kg/s), Supply air specific enthalpy (kJ/kg), Return air specific enthalpy (kJ/kg), Zone air specific enthalpy (kJ/kg). Make sure all inputs use the specified units for consistent results

What assumptions does this calculator use?

This calculator uses automatically validated engineering formulas. Results are approximate and should be validated against site-specific conditions, applicable codes, and professional engineering judgment