Water Damage Restoration Technician (WRT) Certification Practice Test 2026 – Your All-in-One Guide to Mastering the Exam!

Vapor pressure, dew point, and humidity ratio are all key concepts in understanding the moisture content in the air and how it relates to water damage restoration.

Vapor pressure is the pressure exerted by water vapor in the air. It varies with temperature and represents the amount of moisture that the air can hold. As temperature increases, the capacity of air to hold moisture also increases, resulting in a higher vapor pressure.

The dew point is the temperature at which air becomes saturated with moisture, meaning it cannot hold any more water vapor, and condensation begins to form. A higher dew point indicates a higher amount of moisture in the air, which correlates to higher vapor pressure.

The humidity ratio, also known as the mixing ratio, is the mass of water vapor present in a unit mass of dry air. It provides a quantitative measure of moisture in the air.

These three elements are directly related because an increase in vapor pressure indicates a higher concentration of moisture, which will subsequently increase both the dew point and the humidity ratio. Thus, when you understand one of these factors, it can help you predict the others, demonstrating their direct relationship. This relationship is crucial for professionals in water damage restoration, as it aids in assessing moisture levels and developing effective drying strategies.