TABLE OF CONTENTS


COSTIC Data Source


The integrated COSTIC data pertains exclusively to Unified Degree Days (DJU), or heating degree days based on 18°C, calculated using the "energy professional" method.

These data are sent every ten days at a daily time interval from September to June. There are no COSTIC data available for July and August.


Degree Day Calculation Method


Heating Degree Days (Deficit)

  • S > Tmax (common in winter): DJ = S - Tm
  • S < Tmin (exceptional at the start or end of the heating season): DJ = 0
  • Tmin < S < Tmax (start or end of the heating season): DJ = (S - Tmin) × [0.08 + 0.42 × (S - Tmin) / (Tmax - Tmin)]


Cooling Degree Days (Surplus)

  • S > Tmax: DJ = 0
  • S < Tmin: DJ = Tm - S
  • Tmin < S < Tmax: DJ = (Tmax - S) × [0.08 + 0.42 × (Tmax - S) / (Tmax - Tmin)]