## How is enthalpy calculated?

Use the formula ∆H = m x s x ∆T to solve. Once you have m, the mass of your reactants, s, the specific heat of your product, and ∆T, the temperature change from your reaction, you are prepared to find the enthalpy of reaction. Simply plug your values into the formula ∆H = m x s x ∆T and multiply to solve.

**What is enthalpy in HVAC?**

Enthalpy is defined as the amount of internal energy within a system combined with the product of its pressure and volume. When dealing with the term in the HVAC industry, we usually assume that the process is at a constant pressure and, as such, the change in enthalpy is equal to the heat absorbed or released.

**What is entropy in HVAC?**

Entropyis the measure of the disorder of a system. Sometimes defined as the energy of a system that is not available to do work. Systems decrease in energy and increase in entropy over time. The process is not reversible. Temperature Scalesare used to measure temperature, not directly heat.

### What is enthalpy of moist air?

The enthalpy of moist air is the sum of the enthalpy of the dry air and the enthalpy of the water vapour.