Thermal Energy Demand Intensity - TEDI is the annual heating energy demand for space conditioning and conditioning of ventilation air. In other words, TEDI is the amount of heating energy that is output from any and all heating equipment per unit modeled floor area. The heating equipment includes hot water, gas, electric or DX heating coils of the central air system, and any other equipment used for space conditioning and ventilation. Also, the heating output of any heating equipment whose source of heat is not directly provided by a utility must be counted towards the TEDI. Important to note that TEDI does not include mechanical efficiencies of equipment.
TEDI is formulated as the summation of space and ventilation heating output divided by modeled floor area. TEDI is reported in kWh/m2/year. Only the state of British Columbia in Canada formally utilizes TEDI to improve building envelope performance, however, it is a useful metric in any heating-dominated climate. In the platform, TEDI is provided for any project in Canada.
Formal Equation City of Vancouver Energy Modelling Guidelines version 2.0
Location of the TEDI output on the Baseline page.
What impacts the TEDI value?
The key inputs which have an impact on TEDI are listed below:
Envelope Performance Inputs (such as Wall, and Roof U-values)
Heat Recovery System
Building Energy Management System
Exhaust Recirc. %
What does not impact the TEDI value?
Heating System COP
Why consider TEDI at all?
As opposed to EUI, TEDI only considers the design aspects that limited the overall demand for heating in a building. By targeting low TEDI, designers focus on passive solutions like good insulation, air tightness, and beneficial sun angles that help reduce energy use directly. Looking at these passive design aspects is always the first step in a high-performing design.