Calcul Degré Heure Re2020

What are degree hours?

Degree hours are a measure of heating or cooling demand for a building. They represent the product of the temperature difference between indoor and outdoor conditions and the time period over which this difference exists. For heating degree hours (HDD), the calculation is based on temperatures below a base temperature (typically 18°C for RE2020). For cooling degree hours (CDD), it's based on temperatures above a base temperature (typically 22°C for RE2020).

These calculations are crucial for determining a building's energy performance and compliance with energy efficiency standards.

RE2020 compliance requirements

The RE2020 regulation in France establishes minimum energy performance requirements for buildings. One of the key metrics used is degree hours, which helps assess the heating and cooling needs of buildings. Compliance with RE2020 requires that buildings meet specific degree hour targets based on their size and location.

Key compliance points

• Buildings must demonstrate that their energy consumption is in line with the degree hour requirements
• Degree hour calculations must be based on actual weather data for the building's location
• Buildings must provide documentation of their degree hour calculations to demonstrate compliance

Calculation method

The calcul degré heure RE2020 involves several steps to accurately determine a building's heating and cooling requirements:

1. Collect hourly weather data for the building's location
2. Determine the appropriate base temperatures (18°C for heating, 22°C for cooling)
3. Calculate heating degree hours for each hour when outdoor temperature is below the heating base temperature
4. Calculate cooling degree hours for each hour when outdoor temperature is above the cooling base temperature
5. Sum the degree hours for the entire period to get the total heating and cooling requirements

The calculation can be performed using specialized software or manual methods, but it's essential to use accurate weather data and follow the specific requirements of the RE2020 regulation.

Example calculation

Let's consider a simple example to illustrate how degree hours are calculated. Suppose we have the following hourly outdoor temperatures for a single day:

Using a heating base temperature of 18°C and a cooling base temperature of 22°C, we can calculate the degree hours as follows:

In this example, the building has 180 heating degree hours and -38 cooling degree hours for the day. The negative cooling degree hours indicate that the building did not require cooling during this period.

Interpreting the results

Interpreting degree hour calculations requires understanding how they relate to a building's energy performance and compliance with regulations like RE2020. Here are some key points to consider:

• Higher heating degree hours indicate greater heating demand
• Higher cooling degree hours indicate greater cooling demand
• Degree hour calculations help determine appropriate heating and cooling systems
• Comparing degree hours over time can identify energy efficiency improvements
• Degree hours are used to assess compliance with energy performance standards

By analyzing degree hour calculations, building owners and managers can make informed decisions about energy efficiency measures and compliance with regulations.