1. What is Heating Degree Days (HDD)?

Definition: HDD is a measurement designed to quantify the demand for energy needed to heat a building.

Purpose: It helps energy companies, meteorologists, and building managers estimate heating requirements and energy consumption.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( HDD \) — Heating Degree Days (degree days)
• \( T_{base} \) — Base temperature (typically 65°F)
• \( T_{avg} \) — Daily average temperature (°F)

Explanation: For each day where the average temperature is below the base temperature, the difference is added to the HDD total.

3. Importance of HDD Calculation

Details: HDD values help in energy planning, HVAC system sizing, and comparing weather patterns between different periods or locations.

4. Using the Calculator

Tips: Enter the base temperature (default 65°F) and comma-separated daily average temperatures. The calculator will sum all degree days when average temperature was below the base.

5. Frequently Asked Questions (FAQ)

Q1: Why is 65°F commonly used as base temperature?
A: 65°F was established as the temperature at which buildings typically need heating to maintain comfortable indoor conditions.

Q2: How do I get daily average temperatures?
A: You can calculate them as (daily high + daily low)/2 or obtain them from weather stations or online sources.

Q3: What's a typical HDD value for winter?
A: This varies by location. Northern US cities might have 5,000-10,000 HDD per year, while southern cities might have 1,000-3,000.

Q4: Can I use Celsius instead of Fahrenheit?
A: Yes, but you'll need to convert all temperatures to Fahrenheit for this calculator or adjust the base temperature accordingly.

Q5: How is HDD used in energy bills?
A: Utility companies often use HDD to normalize energy consumption data when comparing different periods.