Cooling Degree Hours Calculator

Calculate Cooling Degree Hours (CDH)





Formula

The formula to calculate the Cooling Degree Hours (CDH) is:

\[ CDH = (T - T_b) \times t \]

Where:

What are Cooling Degree Hours?

Cooling degree hours (CDH) are a measure used in the field of meteorology and HVAC (heating, ventilation, and air conditioning) to quantify the demand for energy needed to cool a building. CDH is calculated by taking the difference between the outdoor temperature and a base temperature (usually 18°C or 65°F) and multiplying it by the number of hours the temperature remains above the base temperature. This metric helps in understanding the cooling requirements and energy consumption for air conditioning systems over a specific period.

Example

Let's say the temperature (T) is 25°C, the base temperature (Tb) is 18°C, and the time (t) is 5 hours. Using the formula:

\[ CDH = (25 - 18) \times 5 = 35 \]

So, the cooling degree hours (CDH) is 35.

Extended information about "Cooling-Degree-Hours-Calculator"

Calculate Cooling Degree Days

Definition: Cooling degree days (CDD) measure how much (in degrees) and for how long (in days) the outside temperature was above a certain base temperature.

Formula: \( \text{CDD} = \sum (T_{\text{avg}} - T_{\text{base}}) \)

Example: \( \text{CDD} = (25 , \text{°C} - 18 , \text{°C}) + (27 , \text{°C} - 18 , \text{°C}) \)

Cooling Degree Days Formula

Definition: The formula for calculating cooling degree days.

Formula: \( \text{CDD} = \sum (T_{\text{avg}} - T_{\text{base}}) \)

Example: \( \text{CDD} = (30 , \text{°C} - 18 , \text{°C}) + (28 , \text{°C} - 18 , \text{°C}) \)

Calculation of Rate of Cooling

Definition: The rate of cooling is the change in temperature over time.

Formula: \( \frac{\Delta T}{\Delta t} \)

Example: \( \frac{20 , \text{°C} - 15 , \text{°C}}{2 , \text{hours}} \)

Heating and Cooling Calculations

Definition: These calculations determine the heating or cooling load required to maintain a desired temperature.

Formula: \( Q = mc\Delta T \)

Example: \( Q = 5 , \text{kg} \times 4.18 , \text{kJ/kg°C} \times (25 , \text{°C} - 20 , \text{°C}) \)

Heating Degree Days Calculator

Definition: Heating degree days (HDD) measure how much (in degrees) and for how long (in days) the outside temperature was below a certain base temperature.

Formula: \( \text{HDD} = \sum (T_{\text{base}} - T_{\text{avg}}) \)

Example: \( \text{HDD} = (18 , \text{°C} - 10 , \text{°C}) + (18 , \text{°C} - 12 , \text{°C}) \)